The BLUF (bottom line up front): Research into the biology of long-living older adults reveals unique differences in so-called super agers and centenarians vs other people, and suggests what we can do to help us live longer, too.

The bodies and brains of very old and healthy people are roadmaps with some useful directions for people interested in aging with existential strength.

Two recent studies examined complementary facets of what separates so-called super agers—people who live well into their 80s in superb health—and centenarians from everyone else. Each report suggests that the biology of staying remarkably fit in body and mind may be far more flexible than most people over 50 have been led to believe.

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Join me on a live chat on Wednesday, March 4, at 10am Pacific Time / 1pm Eastern Time / 6pm GMT. Join me for a lively conversation about aging, ageism, strength & fitness, food & nutrition, sleep, stress, sex, menopause (I’m not an expert but I recently interviewed someone who is), and any other subject relevant to life after 45. I’ll happily take your questions, suggestions, curses and criticisms.

Find the chat thread here: https://www.agingwithstrength.com/chat

In other words: the new science supports the idea that moving your body with purpose daily, and feeding it whole food and clocking sufficient sleep, puts you in position for maximum healthy longevity. (For paying subscribers, here are several actionable recommendations to move and feed your body like its 1899).

What the centenarian & super ager studies revealed

The research on Swiss centenarians (press release here; scientific paper here) finds that certain 100‑year‑olds have blood protein patterns that look more like those of middle‑aged adults.

The new examination of brain tissue taken posthumously from “super‑agers” in their 80s (decent NYT summary here; scientific paper here) finds that they made roughly twice as many new brain cells as their peers, helping them keep unusually sharp memories.

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Together these findings suggest that, even very late in life, the brain and body can stay far more youthful than we once thought.

• People in their 80s with exceptional memories are still growing roughly twice as many new brain cells in a key memory region as their peers, the super agers study found. The study also found that Alzheimer's leaves marks on the physical structure of brain cells before those cells even start changing how their genes behave — suggesting the disease may be taking hold earlier than previously understood.

• 100‑year‑olds who reach that age in relatively good shape carry blood protein patterns that look closer to those of middle‑aged adults and, fascinatingly, have significantly lower levels of antioxidant proteins than the standard geriatric population—the opposite of what one might expect, since antioxidants combat “free radicals” that damage cells, proteins, fats and DNA.

  • A note about the paper’s methodology: The researchers did not document nutrition, exercise or lifestyle factors. Rather, they drew blood from 39 Swiss centenarians 100–105 yrs old, a few dozen hospitalized octogenarians (aged 80–90) and 40 healthy younger adults aged 30–60, then measured 724 proteins across inflammatory and cardiovascular panels. The paper is part of a larger analysis of centenarians called The SWISS100 Project.

For anyone over 50, 60 or 70, that raises the stakes on unglamorous habits—how often you actually move, how hard you exercise, what you eat, how well you sleep, and whether you keep forcing your brain to learn difficult new things—because those day‑to‑day decisions appear to feed directly into the same systems that help a small minority stay sharp and physically capable deep into old age.

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Put yourself in position to live healthier for longer by:

• Moving your body. Every day. With purpose.

  • Walking every day is good. Walking briskly is better.

  • Three-minute mini-workouts you can do at home in street clothes with no equipment help build strength & flexibility across multiple planes of motion.

  • Resistance training builds muscles you’ll need.

• Shopping for whole foods (ie, food that spoils if you don’t eat it) and think of eating meals based on lean meats & fish, beans & legumes, olive/avocado oil and greens.

• Sleeping 7–8 hours a night, optimally on a regular schedule.

• Working on one hard mental task each week (learn, practice, or memorize something new).

• Practicing daily gratitude and, by all means, daily self-forgiveness.

See you on Wednesday’s live chat, if you can make it.

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The billion-dollar longevity industry has become the Las Vegas of clinical science: a faux oasis that cares about only one thing—taking your money. To do that, Vegas built casinos; longevity marketers just lie.

Longevity literacy is therefore a skill—the ability to understand how a growing society of wellness chiselers and charlatans present half-truths as settled science and unproven supplements as the best $149 purchase you’ll ever make—but only if you act now.

lon·​gev·​i·​ty chis·​el·​er, n. someone who intentionally promotes unproven anti-aging claims or misrepresents science for financial gain, often unacknowledged.

Below are three recent examples of how agents in the Longevity-Industrial Complex take advantage of their own readers—their most dedicated customers—to enrich themselves or burnish their reputations. I know some AGING with STRENGTH readers don’t enjoy articles like this one and, candidly, I don’t enjoy writing them. But I believe pushing back against wellness hype is important, to set a standard for the future.

Let’s get into each longevity literacy example in detail.

1 | Dr. Mark Hyman misrepresents research to sell a supplement

Hyman is a well-known and relentless figure in Big Longevity. He runs his own branded website and co-founded an online wellness site, Function Health. He’s published best-selling books and prominently advertises his proximity to famous influencers.

On Sunday, subscribers to Hyman’s newsletter woke up to an email, titled, “A Non-Negotiable in My Healthy Aging Routine.” In the first paragraph, Hyman presents his hook, which is “the science behind how you can slow biological aging,” and then baits that hook with a saturated fatty acid called C15:0, which, Hyman says, has “caught my attention.”

Turns out there’s a C15:0 “standout supplement” called fatty15. Hyman enthusiastically recommends it, citing 15 research papers to support his assertion that fatty15 can “improve our everyday lives.” And, as luck would have it, fatty15’s manufacturer is offering Hyman’s “community” a 20% discount.

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But what he presents as a personal anecdote of research and discovery is, in fact, an unacknowledged sales pitch.

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EDITOR’S NOTE: I reached out to Dr. Hyman and his website’s support staff by email several time, asking for his response to my questions about his financial relationship to fatty15 and his interpretation of the clinical studies about its active ingredient. He did not respond. A representative from the DrHyman.com support staff replied, suggesting I review Hyman’s website writings.

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The undisclosed commercial relationship

Though he doesn’t acknowledge it in his email, Hyman financially benefits from fatty15 sales (the supplement’s website identifies Hyman as a paid promoter of the product). Hyman also sells fatty15 directly through his own website, with his own branded product page and has a promotional code relationship with the company.

Hyman’s email structured as a personal letter from a doctor (“as I dug into the emerging research…”) is actually cloaked marketing of a product pipeline.

The intentional misrepresentation of research to sell supplements

Hyman’s email dives into what seems like convincing evidence that fatty15 is a supplement with a proven clinical track record. Hyman cites no fewer than 15 research studies. But in fact:

• Almost none of the research Hyman cites was conducted in humans, and the two studies that were found effects too small, too narrow, and too preliminary to support anything he's claiming

• Several of the 15 cited studies are authored by the co-founder and CEO of fatty15’s manufacturer, Seraphina Therapeutics.

• Several other papers Hyman cites studied only mice, rabbits, or dolphins, or involved petri-dish experiments on isolated human cells — the kind of early-stage science that routinely fails to translate into human benefits.

• The only human clinical trial of C15:0 supplementation in Hyman's entire reference list involved 30 obese 20-year-olds, and across most key measures—cholesterol, blood pressure, glucose, and inflammation—found no significant improvements.

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None of the 15 papers Hyman cites is a randomized, controlled trial testing C15:0 in healthy middle-aged or older adults — which is precisely the population to which he’s surreptitiously marketing.1

I asked two longevity scientists about Hyman’s representation of the research behind fatty15. One of the scientists said the supplement may have potential but has “extremely weak evidence for human benefit at this point.” The other scientist called Hyman’s email “100% advertisement.”

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“I looked up this product…a while back and read through a lot of those papers,” this scientist told me. “There is no data worth citing, all conjecture and animal data designed to sell a ‘new’ type of fatty acid.”

The sad part is that C15:0 might turn out to have real benefits for people. Hyman’s fatty15 hustle may turn out to be everything he already says without evidence that it is. But when a doctor says things that aren’t fully supported by science, it’s a longevity scam.

2 | Katie Couric Media disguises a supplement ad as straight journalism

Before she became infamous for hanging out with Jeffrey Epstein, Katie Couric had been famous for being a journalist, and rightly so. Today, she runs what appears to be a rather successful media company that blends soft-focus marketing content with some wellness advocacy. But Couric still trades on her previous career as a broadcast news maven, so when her company publishes what looks like reporting, there’s an expectation of transparency and truth.

Which is why I was surprised when I came across a Katie Couric Media article whose headline, I’ve Tried Countless Wellness Products — This One Is Different, sounded like straight-up marketing. The subtitle, Showing your liver some love has never been easier, felt like Marketing 101. But okay, I’m an old-school reporter. Maybe I was just being a curmudgeon.

Turns out the article, whose opening line is, “I’m a sucker for a good Instagram ad,” is a wet-kiss “advertorial” for a liver supplement called Dose. But there’s nothing at the top of the post to alert readers. To the contrary, the post is presented as a piece of (flabby) reporting. To appear more like a real news story, it even includes an interview with “an expert in the dietary supplement and nutrition market,” Kiran Krishnan.

“As an expert, Krishnan can vouch that the brand has done rigorous clinical research,” the article squeals, “to show that Dose’s clinically backed formula is effective in supporting liver health.”

What the article does not disclose is that Krishnan is a member of Dose’s scientific advisory board. At the bottom of the piece, an icon reveals that it was “sponsored by Dose,” and the penny dropped for this reporter.

So it’s an ad. Who cares?

As with Hyman’s email, you may ask: What’s the big deal? Anybody with a nose for b.s. would quickly determine that this fluff piece wasn’t a New York Times investigation. And that’s a fair point. What’s also fair is treating your readers, who are your customers, with enough respect to be transparent in your operations. In this case, that means putting the sponsorship notification at the top of the post, so readers can decide for themselves what value, if any, to give a piece of marketing schtick masquerading as reporting.

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Transparency doesn’t sell supplements, apparently.

3 | A university dementia study opts for misleading clickbait headlines

Could diet soda increase dementia risk? That was the head-turning headline of a recent article by the University of Miami’s medical school (or probably more accurately, the school’s marketing department) to stoke attention to its new analysis.

When a university medical school publishes research, there’s a very reasonable expectation of accuracy, without which public trust in even that institution will quickly fade. I’ve written previously about Stanford aging research that didn’t quite back up what the medical school’s press release claimed.

But I haven’t before seen a university medical school so blatantly imply a potential spit-out-your-diet-soda conclusion—drinking Diet Coke could bring on dementia—before acknowledging a few paragraphs later that, in fact, it doesn’t.

“A new analysis…suggests that drinking diet soda every day may be linked to a higher risk of developing dementia,” the article, published Jan. 26 by Miami’s Miller School of Medicine, reported. Some 15 paragraphs later, the article casually mentions that:

”41% of high diet soda consumers in the study had diabetes, compared with 18% of the rest of the cohort.

“When researchers repeated the analysis excluding participants with obesity or diabetes, the association between diet soda and dementia disappeared.”

Translation: Nevermind! Nothing to see here, folks. Thanks for coming.

That’s why I believe it’s necessary to publish analyses of poor or disingenuous longevity and wellness marketing intentionally disguised as honest reporting. In this case, a peer-reviewed research paper published in the Journal of Alzheimer's Disease stood up a straw-man argument with a juicy headline before essentially knocking it down.

Yet another reason why longevity literacy matters now more than ever.

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This article was updated on Feb. 10 to include Diamandis’s attempt to visit Epstein’s New Mexico ranch in 2008 and his 2014 interactions with Epstein at a TED conference, according to documents that are not in the Justice Department’s files. They contradict Diamandis’s statement that he was “introduced” to Epstein only in 2013.

Peter Attia isn’t the only notable longevity-wellness industry figure who went out his way to engage with registered sex offender Jeffrey Epstein after Epstein pleaded guilty to procuring a child for prostitution.

, the founder and executive chairman of the XPRIZE Foundation and the co-founder (along with Tony Robbins) of a longevity clinic that charges more than $10,000 for its most basic membership, pursued a connection to Epstein over at least a six-year span, from 2008 to 2014, records show. Notably, Diamandis says he “was introduced” to Epstein in 2013, though emails show him arranging an in-person visit with Epstein five years earlier.

As of this writing, Diamandis has not offered a public explanation of the disparity.

Why this matters: the longevity industry’s integrity problem

In the billion-dollar wellness industry, transparency and sound judgment matter—because they’re often in questionable supply. Diamandis, who earned a Harvard medical degree, is one of the most prominent evangelists and entrepreneurs in the longevity-industrial complex. He charges up to $250,000 to give a speech, so clearly his words and actions matter greatly to a lot of people. He co-founded two venture-backed companies; Fountain Life, with Robbins, and Human Longevity Inc., that sell premium diagnostics and concierge health services to wealthy clients, marketed around the idea that, if you can pay enough, aging can be slowed or reversed.

Ambition is admirable, but so is speaking candidly to the people paying you. At a time when the longevity industry is bloated with misdirection, false claims and shaded truths, the people at the top should practice more transparency, not less.

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Diamandis & Epstein: unanswered questions

In May 2008, Diamandis wrote an email to Epstein’s assistant connecting Epstein to a business associate of Diamandis’s and asking for “proposed dates” to meet at Epstein’s New Mexico ranch, documents show. The email was sent about seven weeks before Epstein pleaded guilty to procuring a child for prostitution and began serving his jail sentence in Florida, on June 30, 2008.

Whether the men actually met in person that year is not clear. (You can peruse the Jmail trove of all Epstein files, including many not included in the Justice Department’s file, in a format vastly more searchable than the government’s.)

In April 2009, while Epstein remained incarcerated but was allowed to leave jail from 8am to 8pm six days a week, Diamandis emailed him directly seeking a “catchup.”

“Hi Jeffrey- It’s been a while since we chatted,” Diamandis wrote. “I’d love to connect and catch-up,” he added. “Are you in NYC or Florida these days?”

There is no indication in any public record thus far that Diamandis’s connection to Epstein went beyond business interests.

Diamandis’s response to this article

A day after this article first published, on Feb. 4, Diamandis responded with a statement in two parts that minimize his connection to Epstein and contradict the historical record of their six-year correspondence, most of which occurred after Epstein’s public reputation has become odious to many.

Diamandis says he was “introduced” to Epstein in May 2013 by his book publisher, who later urged him to meet with Epstein to discuss an XPRIZE donation. “I had a single fundraising meeting with Epstein about XPRIZE,” Diamandis says in the first part of his statement. “That’s it.” He also says, “Had I known more about him, I would have never pursued a meeting.”

In the second part of his statement Diamandis says his introduction to Epstein occurred at “TED Monterey,” facilitated by the publisher, John Brockman, during a group dinner. “We introduced at that time but we didn’t connect beyond an initial introduction,” Diamandis wrote. “It was later that Brockman suggested that I approach Epstein for XPRIZE Funding, which I did.”

But emails show Diamandis had wanted to visit Epstein at his New Mexico ranch as early as 2008 and had asked Epstein to reconnect and catch up in 2009. Moreover, the Brockman group dinners occurred at the main TED conference, which in 2013 wasn’t in Monterey. Further, an email exchange between Diamandis and Epstein in March 2014 (see below), suggest they had interacted at the big TED event in Vancouver that year, not 2013.

Notably, by 2014, TED conference organizers had barred Epstein from attending, so he held meetings in hallways and a hotel lobby—and apparently also attended Brockman’s dinners.

“Hi Jeffrey- Great to see you too.”

By May 2013, Diamandis’s and Epstein’s mutual interest in meeting was clear. “Jeffrey wants you to please contact him whenever you come to New York….he would love to get together,” Epstein’s assistant wrote to Diamandis in May 2013. Diamandis replied the same day, asking his assistant to “figure out when I’m next in NYC & schedule time with Jeffrey.” On June 9, 2014, Diamandis was scheduled to see Epstein for an hour-long meeting, these documents show.

This is a note I published on Feb. 10 after coming across the Jmail rendering of further emails between Diamandis and Epstein.

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Epstein later wrote to another acquaintance about Diamandis: “know him well.”

In an email sent a couple weeks before meeting Diamandis at a TED conference and three months before the two men arranged to meet in New York, Epstein referred to Diamandis as a “bullshitter.”

Only a fraction of the more than 270 documents in the government’s Epstein files that include Diamandis’s name are personal correspondences between the men or their assistants. Many are versions of the same emails.

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Other health and wellness entrepreneurs in Epstein’s orbit

The overall longevity market, encompassing complementary and alternative medicines, gene sequencing, and anti-aging therapies and products, generated $65 billion in revenue in 2023 and is projected to reach $314 billion by 2030.1

The two Peters—Attia and Diamandis—were hardly the only luminaries in the longevity-wellness industrial complex to have associated with Epstein.

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So did Bryan Johnson, the wax-skinned tech bro who wants people to pay him $1 million to avoid death. So did Katie Couric, who attended (now arrested former) Prince Andrew’s birthday party—and rearranged weekend plans to have tea at Epstein’s New York City home—17 months after he was released from prison. So did Deepak Chopra, who met with Epstein at least 12 times between 2016 and late 2018, during which time Chopra published two NYT best-selling self-help books, including “The Healing Self: A Revolutionary New Plan to Supercharge Your Immunity and Stay Well for Life.” So did George Church, a Harvard genetics professor and longevity business entrepreneur who, along with two Harvard colleagues, once proposed Epstein fund a “pleasure genome initiative” exploring neural correlates of pleasure, and who shared meals with Epstein as late as 2014.

The list goes on. Each of the above names has offered what feel like regretful if also professionally vetted apologies or explanations for their interactions with Epstein.

A few thoughts on Peter Attia’s relationship to Epstein

What distinguishes Attia’s relationship with Epstein from all the others is that:

• he wrote to Epstein with crude comments about women’s bodies

• he has wrestled with deep emotional issues that he described with admirable candor in his best-selling 2023 book, Outlive: The Science and Art of Longevity

• unlike almost everyone else with a direct, personal connection to Epstein, he’s made no excuses for his interactions with the man

A day before this article published, Attia, who is 52, posted a lengthy statement on X (fitting, considering Elon owns the often vile, increasingly toxic platform and is also featured in Epstein’s emails) to his staff, explaining his relationship with Epstein and not attempting to defend his crude sexualized remarks. You can read Attia’s statement here.

The cancellations begin

Attia, who CBS News just hired a week ago as a special health-wellness-longevity guru-slash-correspondent, is not expected to hold that job for much longer. For many people, the Epstein revelations were the disappointing icing on the proverbial cake—a layer cake of Attia product affiliations (like the overpriced David protein bar, which until Monday had paid Attia to be its chief science officer) and business ventures (like his high-end longevity clinic chain, Biograph, which he launched from stealth with a venture capitalist a year ago) that create real or perceived conflicts of interest.

The heartbreaking failure

Then there’s the most damning, heartbreaking Attia failure of all, which he himself disclosed on page 379 of his book, in a chapter titled “Work in Progress”: In July 2017, during a business trip to New York, Attia received a panicked call from his wife: their one-month-old son had stopped breathing and nearly died before being revived with CPR, and was in an ambulance to the ICU. His wife pleaded with him to come home. But instead, Attia wrote, he stayed in New York—for another 10 days—because of what he called “important” (his quotes) work.

That work, it turns out, involved a few meetings with Epstein, according to the time stamps on Attia’s emails released by the government. He chose that work over his family—his desperate, fragile family in a world of pain. It’s hard to fathom.

What happens next?

Peter Attia is almost certainly now in the process of disappearing, voluntarily or otherwise, from our collective longevity consciousness. At least for a while. (Peter Diamandis may lose a few speaking engagements but is not likely to disappear, is my guess.) Does that mean that Attia’s book, Outlive, which contains a lot of objectively valuable explanatory and clinical information about living better for longer, should no longer be read or discussed, due to the extreme failures of its author?

At a time when many Americans see equally poor, if not worse behavior from many other public figures in entertainment, academia and, especially, government, time will tell.

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Substack has many problems these days. One of them that should concern us all is the increasing number of medical doctors — and those who call themselves doctors — who publish health and wellness content that feels like AI-generated boilerplate.

I’ve been contemplating whether to write this post for a while now. Will anyone care? After all, AI is everywhere, and even Substackers that shamelessly copy/paste ChatGPT twaddle below their bylines still manage to accumulate dozens of likes and comments. Maybe readers don’t mind being spoon fed machine-made thoughts.

But after speaking with a few doctors on Substack who don’t use AI to write their posts, I realized I wasn’t alone in my growing dismay at the preponderance of rote, AI-derived health & wellness information on Substack. One doctor who has a substantial Substack following sent me a note that concurred.

“The funny/sad thing is that people seem to like it,” this doctor told me. “Mindless to write, mindless to read. I feel like it steals potential intellectual capital from over-50 readers. And longevity literacy has got to be impaired, too.”

In case you missed it….

Agreed. So I decided it was time to investigate how AI is now infiltrating what is starting to feel like the Substack health and wellness industrial complex. What I found, within and beyond Substack, was revealing and dismaying, compelling and crude — and probably just the tip of the AI iceberg that could sink all our ships, if we’re not careful.

Longevity literacy in the age of AI

Before I dive into the Substack doctors whose work I examined, let’s first take a step back to view the extent to which AI, in the hands of non-licensed, unscrupulous humans, is gaslighting us every day. (Last year, a Substack writer tackled the rising use of AI on the platform in a post that, according to a leading AI text analyzer, appears to be substantially AI generated.)

Esther Perel deepfakes posing as therapeutic advice

The three YouTube videos below are a prime example of why all of us need to develop what I call longevity literacy — without which we’re susceptible to believing, taking advice from or giving money to some of the worst people on the internet.

Each of these videos is from a different YouTube channel and claims to depict Esther Perel, the renowned psychotherapist, giving advice about a ridiculous subject. They each sound very much like Perel and, in the case of the first video below, look like her. But each is a deepfake — entirely AI generated.

The first video below may be the creepiest of the three.

UPDATE Jan. 1, 2026: After I published this article, YouTube removed all three videos below, which were AI deepfakes of Esther Perel talking about what women want from men and how they show their needs — utter AI bullshit. Unfortunately, many other AI-generated deepfakes of Esther Perel, like this one immediately below, persist on YouTube.

For about the first minute, you wonder why Perel would speak so condescendingly about how sexually needy women over 60 respond to men. Then comes the creepy part: At the 00:55 mark, AI Esther Perel pauses and announces: “Hi, It’s Vernon again….” and asks you to like and subscribe to his channel.

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And so you wonder: If YouTube can’t or won’t fight off its own egregious, almost certainly defamatory AI enshittification, is resistance to global AI enshittification futile? If so, who cares if doctors on Substack publish information that may come straight from, or be filtered through, AI?

Why we should hold doctors to a better-than-AI standard

We should all care, I think, because doctors — including those on Substack — aren’t just content machines who can ethically trade in the trust readers give them for a warehouse of AI-derived insight and instruction. That’s not transparent at all.

“When a physician publishes health explanations, the MD (or equivalent) degree after their name signals training, experience, judgment and accountability,” , a cardiologist, told me in response to my questions about doctors publishing content that appeared to be AI generated. “Readers reasonably assume that the analysis reflects the clinician’s actual expertise and that the author takes responsibility for the accuracy of the claims. When the substance is outsourced to AI, that trust is misplaced. It misleads the public and, in my opinion, crosses an ethical boundary.”

Running Substack docs’ content through an AI text analyzer

With that in mind, I spent this week reading through several Substacks published by 6 health & wellness professionals — 5 medical doctors (and one who calls herself “doctor”) to get a sense of whether and how much they routinely use AI in their posts.

I ran selections of their Substack-published work through a leading AI text analyzer, GPTZero, which claims to be able to discern AI prose from human writing with high confidence, and which Wired magazine has previously used to analyze other Substack content for AI influence. I then reached out to each person, to ask if and how much they use AI in their Substacks.

The results of that reporting are below. Two of the six people, Howard Luks MD and Mohammad Ashori MD, responded at length to my questions; the four others did not. One doctor, Laurie Marbas MD, MBA, blocked me.

It’s important to say clearly that this exercise is one of transparency, not playing gotcha. I wish my reporting had turned up no evidence of AI at all. Since it did, I hope this post leads to a greater awareness among readers and, indeed, greater transparency among MDs who regularly lean on AI to generate health & wellness advice.

In no particular order:

Laurie Marbas MD, MBA, who publishes The Habit Healers on Substack

• Dr. Marbas blocked me and did not respond to several requests for comment.

• Dr. Marbas is notable for her large following and for being a prolific producer of Substack content, posting lengthy, encouraging and prescriptive articles almost daily.

• GPTZero indicates many posts are mostly or entirely AI generated, including this one on how cold water impacts health (here’s the GPTZero report on that post); and this one on movements that are better than workouts (here’s its GPTZero report). And several others.

• The AI tool also indicated that the introduction of Dr. Marbas’s book, “Plant-based 101,” published in January, was likely AI generated. Many parts of her published work, in fact, carries the anodyne vernacular of AI, and the online analyzers corroborate that impression.

, an orthopedic surgeon who writes Built to Move, Born to Heal: Notes on Midlife Fitness on Substack

Dr. Luks also blocked me, on April 4, 2026, after I disputed his Note — now scrubbed of our politely adversarial exchange in comments —declaring that weight training provides no aerobic benefit. (It does.)

• Dr. Luks has been writing about his work, patients and thoughts on fitness and health for a few decades. He wrote a book and as he told me in a Substack chat, “On my topics, I’ve forgotten more than some will ever know.” He will sometimes use AI, he said, to ensure he’s writing at a level that his non-technical readers most appreciate.

• A few days earlier, he published a post on the importance of not slowing down with age, and when I read it, it reads like cheap, over-the-top AI. (And GPTZero agrees.) The purple prose. The tortured metaphors. The litany of three-word paragraphs. However, Dr. Luks, in an email response to my questions, said he wrote the the post mostly himself. “On short-form posts I will use an AI to edit it…and in some instances to soften it up a bit,” he said. “If, at times I feel that an LLM can enhance the message, so be it.”

• Dr. Luks posts several lengthy, in-depth articles in one 24-hour span, so whether they the result of AI “enhancement” or wholesale generation is not clear.1

• What’s seems more likely is that physicians like Dr. Luks use AI more than they admit. Case in point: it’s hard to read this passage from his Sunday post and not raise an AI-brow:

  Comfort can be a coffin.
  Excuses are chains.
  Your body doesn’t negotiate, and your future will not wait.

  Cry if you must.
  Fight if you can.
  But fight.

  Because time will take everything you refuse to earn…
  and it does not give refunds.

If that’s not AI-generated prose, I’m not sure what is. I think we’d all prefer that Substack writers, especially MDs, disclose when they’re relying on AI to generate content under their names, instead of pretending otherwise. Since this post originally published, Dr. Luks has become more willing to acknowledge how much AI his posts and notes actually contain.

, a cardiac surgeon who publishes Longevity Docs on Substack

• Dr. Luu is an entrepreneur cultivating Longevity Docs’ physician-only audience and who hosts large events in several cities.

• GPTZero indicates many posts, which tend to be extremely long, detailed and lavishly designed with customized photos and graphics, are mostly or partly AI generated, including this one on the “Biomarker gold rush” (GPT Zero report); this one on electronic medical records, peptides and other topics (GPTZero report); and this one on a “longevity clinical trial network” (GPTZero report).

• Dr. Luu did not respond to a request for comment.

, a cardiologist who publishes eponymously on Substack

• Dr. Kelly publishes a mix of first-person posts, including this recent one about an 80-year-old patient’s extraordinary VO2 max results, which the eye test and the online AI tool each indicate is human written; and another on why people die from heart disease, which suffers from tell-tale staccato AI tropes such as:

”You should not die of cardiovascular disease before old age.
Not anymore.
Not with what we know.
Not with the tools we have.”

• (GPTZero rated the post as 40% AI generated)

• And another, more personal story of “when fear becomes physical” that unfolds with similarly common AI phrases and cadence (GPTZero rates it as mostly AI).

• Dr. Kelly didn’t reply to requests for comment.

, a family physician and health coach on Substack

• Dr. Ashori is “an MD turned health coach” and runs an online coaching business, as well as a health-coaching YouTube channel. On Substack, he tackles very practical subjects with mass appeal, such as how to avoid waking up in the middle of the night (GPTZero rates it as almost entirely human written) and how to fix back pain, which the AI tool also rates as penned by a real person.

• Not much of Dr. Ashori’s writing struck me as clearly generated by AI, but in the interest of creating a broad canvas of doctors writing on Substack, I asked him if AI plays a role in what he publishes. Here’s his response, via Substack chat:

• “The practice of writing itself is what I’m after, without it the brain will atrophy quickly,” Dr. Ashori said. “So it’s important that I think about each piece creatively and grammatically. That said, some paragraphs are too verbose or I just can’t get my meaning across. Once I have something written I’ll pick the worst paragraph and ask my AI task manager to rewrite it only for clarity. Most of the time it’s great and I don’t need to make changes. When I have a complete block for an article I want to write I have Chatty [his pet name for ChatGPT] give me some suggested outlines. Usually only with bullet points so I don’t lose the cranial task of coming up with my own content.”

• His comment reminds me of something , creator of Brain Health Kitchen on Substack (and author of an excellent book with the same title), told me recently: That sometimes she congratulates her readers for making it to the end of a particularly thorny topic.

  • “I remind them they are building cognitive reserve,” Dr. Fenn told me. “Just hanging in there and trying to grasp complex topics is one way to build brain resilience. So I want them to feel good about reading stuff that’s hard even though it’s more of an effort than plowing through easy, AI-generated stuff.”

, who writes The Strong Doc on Substack

• She earned a degree in dentistry from an Indian university, according to her LinkedIn page. She is not a medical doctor, which may not be apparent to readers who see the her name preceded by “Dr”, not to mention the name of the Substack itself.

• Most of the posts I reviewed, including one on “invisible fat that’s killing millions,” and another on uric acid, seem plausibly written by AI. (GPTZero agrees.)

• But it seems there are larger ethical concerns about a Substack that gives advice and insight into medical topics if the author isn’t a physician.

• Ms. Chawla did not respond to requests for comment, but after this post published, her business partner left a comment below calling this article “AI slop.”

In summary

GPTZero’s analyses are not dispositive. My hunches could be off base—except in the case of Dr. Marbas, whose production of lengthy articles filled with programmatic advice would be virtually impossible to create without AI. Moreover, my reporting is by no means exhaustive, and, as stated above, it’s not intended to embarrass or play gotcha.

It is, however, a decent argument for greater doctor transparency on Substack.

AI-generated content is likely playing a bigger role in Substack’s increasingly crowded health & wellness category; doctors are among those using AI to produce a growing body of advice and opinion — often without telling their readers. My personal antennae go up when I observe practicing physicians posting lengthy, detailed articles daily or several times a week, when most doctors I know struggle just to see their patients and record their clinical notes.

Maybe I’ll create a separate post that examines Substack’s doctors’ and other other clinicians’ work for evidence that they’re using AI to trade on their credentials. What do you think? Worthy endeavor or “give it a rest, bud”?

One last thing some readers may be wondering about….

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How I use AI and disclose it on AGING with STRENGTH

I use AI almost daily the same way a lot of other Substack writers do: to ask questions, gather information, and tease out ideas that might be worth writing about. The images topping most AGING with STRENGTH posts (but not this one) are courtesy of Midjourney.ai. My posts evaluating longevity supplements and wearable fitness trackers were each created with research help from AI, which I disclosed in each post.

When I use AI in my writing or reporting, I make a point of saying so. That way, the reader can make an informed decision about the information I present. That’s basic communication transparency.

We all want doctors, including those writing about health and wellness on Substack, to be equally transparent, don’t we?

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Inside Longevity™ compiles data that helps you make informed decisions on personal and business opportunities in the longevity and anti-aging industries.

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The table below shows all 16 anti-aging drugs’ disparate effects on males and fe

males, with plain-English explanations of each drug’s mechanism and other key findings from this first-of-its-kind study.

Study Abstract

“Aging is the primary risk factor for frailty, sarcopenia, and functional decline, as well as cancer, cardiovascular and neurodegenerative diseases. Gaining insight into the biological mechanisms of aging could lead to interventions that broadly reduce age-related morbidity and mortality. To identify interventions that extend lifespan and delay aging, the National Institute on Aging launched the Interventions Testing Program (ITP) in 2004. This multi-site effort uses genetically heterogeneous UM-HET3 mice to evaluate the effects of candidate compounds. Over the past two decades, the ITP has tested 54 agents in more than 30, 000 mice. This is the first comprehensive review of the program’s results, with particular emphasis on a striking pattern of sex-specific responses. By presenting the full scope of the findings, readers can better understand the overall impact of the program and easily access detailed information on specific drugs of interest. Notably, most compounds that extended lifespan were effective primarily or exclusively in male mice. Dosage and age of treatment onset influenced efficacy and were also sexually dimorphic. These sex differences suggest that mechanisms of aging are sexually dimorphic and highlight the importance of recognizing biological sex as a modifier of treatment efficacy. Investigating the basis for these differences should enable more targeted and effective geroprotective strategies for both sexes.”

You can read the full research paper here.

What’s in this post:

• The fundamental market advantage of supplement sellers over buyers.

• Thesis: The NAD+ debate: is there proof it works in people?

• What are sirtuins and NAD+? A plain-English overview.

• The two scientists generating the NAD+ hype cycle: how they did it.

• Hitting the resveratrol jackpot, and how resveratrol paved the way for NAD+.

• Profitable consequences: When research PhDs exaggerate their own science.

  ---

There’s a reason you’ve been hearing more about NAD+ shots and supplements lately without feeling like you actually understand what NAD+ is, what it does, how it works, whether it’s worth trying or even why it has become, among celebrities and the so-called “worried well,” such a thing now.

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That lack of scientific clarity, I argue below, is partly by design.

When it comes to longevity supplements, ambiguity favors the PhDs selling them for a profit more than the consumers buying them on a prayer.

This post has a simple thesis: NAD+ may eventually be clinically proven to help people age slower and better, but so far there’s zero proof. That lack of evidence hasn’t prevented it from becoming a popular longevity supplement — especially among those on the Hollywood/Instagram axis. At the core of this massive uptick in NAD+ interest are two scientists, at Harvard and MIT, who for years have flooded the zone with research that, coincidentally or not, gave them a clinical basis to sell online sirtuin/NAD+ pills to consumers who may, or may not, receive a benefit.

But first, in case you missed it:

To keep this post as concise as possible, I’ll stay at a non-clinical level of detail to illustrate how talented but ambitious scientists intent on cashing in on their work can use prestigious medical research publications to foster a misleading narrative that provides those scientists lucrative business opportunities.

This isn’t a rare occurrence. In a longevity industry worth an estimated $5.6 trillion1, it’s become a trend.

TREND: A scientist at a prominent lab publishes research suggesting a promising new way to slow or reverse aging. He (they’re almost all men) joins with MBA types to sell an online supplement derived from that research, though the data on humans is inconclusive at best. Other researchers eventually dispute his public claims, but it’s too little, too late! The scientist and his partners, aided by social media influencers, have already developed their unproven product into a lucrative side hustle in the trillion-dollar longevity marketplace.

In plain English: What are sirtuins and NAD+?

Sirtuins are proteins in your cells that act like maintenance workers. They help repair DNA damage and keeping your cellular machinery running smoothly as you age. There are seven different sirtuins in humans (SIRT1 through SIRT7). They also help regulate everything from brain, immune and circadian function to fat metabolism and blood sugar. To function, however, sirtuins need NAD+, a molecule that is present in every cell of your body and is essential for life. (NAD stands for nicotinamide adenine dinucleotide.)

NAD exists in two forms that function as a pair:

• NAD+ (the oxidized form) has a positive charge, ready to accept electrons

• NADH (a reduced form, where H is hydrogen) is neutral, carrying electrons

These two forms work together in your cells. NAD+ picks up electrons (and hydrogen) during the breakdown of food, becoming NADH, which delivers those electrons to your mitochondria to generate energy and then turns back into NAD+. This cycle occurs constantly, in every cell, thousands of times per second, to keep you alive.

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Will NAD+ therapies be proven to offer positive health impacts on humans? Time will tell. Thus far, there has been no clinical consensus that it does2; some reputable scientists are cautiously optimistic, while others are not. Studies continue to publish on both sides of that clinicial aisle.

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We may find out sooner rather than later, however. The day before this post published on AGING with STRENGTH, the journal Nature Aging printed a new NAD+ paper with 28 authors — including two mentioned in this post.3

The graphic below, from that study, provides a helpful overview of NAD+ functions in cells, mice and humans, with references to correlated studies.

(As you read further, keep the above study in mind, because it illustrates a central point about the growing number of conflicts of interest in clinical research that I mention below.)

Sirtuins, discovered in the 1970s, have been in the scientific literature for decades. They became famous in the late 1990s when research first suggested that activating them in yeast could mimic the life-extending effects of calorie restriction — eating less while staying healthy — which had been shown to help various organisms (but not humans, really) live longer.

Here’s the critical twist:

NAD+ may precipitously decline with age4, thereby inhibiting the ability of sirtuins, which rely on NAD+, to help keep cells healthy, well and, just maybe, young.5

NAD+ and the scientist-led hype cycle

But, what if, instead of just losing our NAD+ supply as we age, people could keep topping it off with further supplements and injections, to give our sirtuins all the juice they need to continue repairing and rejuvenating our cells?

Or, in the PT Barnum-like parlance of David Sinclair, a serial dissembler and controversial6 Harvard geneticist who has falsely claimed to have reversed aging in dogs7; suggested a pill may soon reverse aging in humans; and regularly exaggerates his research:

What if human manipulation of NAD+ could slow aging?

In fact, in 2016, Sinclair published a paper on sirtuin/NAD+ with that exact, provocative, and, it turns out, unsupported title: “Slowing ageing (sic) by design: the rise of NAD⁺ and sirtuin-activating compounds.”8 I say unsupported because the

Read more

Below is Part 2 of my wide-ranging interview of Eric Topol, a cardiologist and one of the top 10 most cited researchers in medicine, about the biggest takeaways from his best-selling new book, “Super Agers: An Evidence-based Approach to Longevity.”

Read Part 1 of our Q&A session, which took place in Dr. Topol’s office at Scripps Research Translational Institute, which he founded, in La Jolla, Calif.

Reporter’s request: This interview has no paywall but required several hours to research, conduct, transcribe, edit and format. If you find what you read here helpful, please consider making a small, fair contribution to support it.

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(This interview has been lightly edited for clarity and length.)

Paul von Zielbauer, AGING with STRENGTH: Your book is a not-so-silent indictment of the American healthcare system, or “sick-care” system, as you’ve called it, which isn’t set up for prevention. Should people be setting aside money, just like they would for a vacation every year, to spend on their own health span?

Eric Topol: This is a really important question you're asking, because firstly, we didn't really have the ways to prevent these big three diseases (cancer, cardiovascular disease and neurodegeneration) before. It's only now. We needed AI for the analytics, and we needed the layers of data, and many of those layers have only recently become available or will soon be available.

We are not in a good position, in this country, to do this. You touched on it because we have a private-insurance based [system], where insurers don't have a long-term interest. They just want to get you or your employer to sign up for another year. Why would they want to prevent the diseases that cost money to prevent? Other countries will do this first because they're looking out for the countrywide health.

In the United States, we have such a perverse incentive system, which is not set up for prevention. To turn that around is going to be hard.

Putting in a prevention savings account, that's not really the problem. The problem is, how do you get these assessments? When are we going to have immune system testing for low cost? And how are we going to get it so it's not just for the affluent but for everyone, because it's an incredibly smart investment?

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It costs huge amounts to treat a person with Alzheimer's or cancer or even cardiovascular disease. Are we ready to invest in prevention and make it across the board, whether it's Medicare, private insurance, whatever? I don't know that our country has the boldness to take on that initiative.

It isn't a prevention system, and it isn't easy to morph it into a prevention system. Just because of the way it's structured.

AGING with STRENGTH: Should people be willing, then, to invest in their own healthcare, even if that means setting aside thousands of dollars every year for tests that insurance won’t cover?

Eric Topol: I'm into that democratization and more self-advocacy for people. The problem is all these companies that are marketing longevity. There's Peter Attia's Biograph, and Function [which Andrew Huberman1 advises], and all the rest. They'll give you all these tests for a big price. That isn't good, because you're doing tests indiscriminately and you're going to find things that you don't know what to do with — they are rabbit holes.

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They're advocating total body MRIs with no data to support it, except for Kim Kardashian's endorsement. So the question is, how do I get the right test for me instead of getting hundreds of tests that I pay big bucks for and I'm going to get these crazy results that are spurious?

It seems rapacious. I’ve advised some of these companies. I ask them why they don't just do the tests that are based on a person's risk. The accuracy is much higher. The idea they have of getting more tests isn’t a good idea [because] It's just getting the wrong tests for the wrong people, and too many tests.

But standard medicine is leaving too many unsolved questions about a person's risk. For example, the medical community has been against polygenic risk scores, which keep getting better every month, every quarter. We can pick up people who don't have any family history of heart disease and very accurately say, “You're at really high risk for heart disease.” And then we can get all over them, prevention-wise.

So why aren't we using polygenic risk scores, which you can get for less than $50? That would be one kind of starting point, because people don't understand that even if [a disease] is not in their families, the unique combination of variants [formed by combining] your mother’s and father's DNA can give you a disease burden that you didn't know about.

And that's how you find it: through a polygenic risk score. Or, for $200, your whole genome sequence, if you're worried about cancer in your family. But we're well past just genomes. Now we're into biomarker proteins.

AGING with STRENGTH: Who isn’t worried about cancer? Especially given what you said about how our DNA isn’t simply the sum of our mother’s and father’s?

Eric Topol: What I would say is, get a polygenic risk score for the cancer conditions, heart disease and Alzheimer's first.

If you have a high polygenic risk score for one of the cancers, let's say colon cancer, then I would get a whole genome sequence to see whether there are certain variants/mutations that add more to that risk. So you start off with a cheap test, 50 bucks, then you get a polygenic risk score. I put in the book a bunch of reputable companies that can do them. Then you go to the genome sequence, for $200.

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Let's say you're at high risk for Alzheimer's. Well, then you get a P-tau 217, you go to Quest Diagnostics, or LabCorp, it costs $190. And then you say, “Okay, my p-tau217 is up. It goes along with all these other things because I have a family history of Alzheimer's, I got an APOE4 allele. But now I have a test that I can use for my exercise and my lifestyle and all these things to bring it down. And hopefully, in the future, GLP-1 or one of the gut hormone remedies or many other drugs that are in the hopper for preventing Alzheimer's.

AGING with STRENGTH: I hear you saying that people do need to sort of be their own Sherlock Holmes here.

Eric Topol: Yes.

AGING with STRENGTH: Don’t start with the tests that are $500, for no good reason, but rather with the affordable tests and then follow that breadcrumb trail. Is that what you're saying?

Eric Topol: Yeah. That's a good way to put it. But don't go and get a total body MRI. Don't do that.

AGING with STRENGTH: What about a DEXA scan, which you can get for $50 or $75?

Eric Topol: That won't tell you about your risk for diseases. That will tell you, if you're on a strength training or weight loss program, [what your percentage of muscle and body fat is]. That's the solution to BMI.

By the way, I should have put in the book, but if you go for a DEXA scan at most hospital systems like mine, all you get is your bone density. You get nothing about your fat and your muscle. So you have to go to one of these strip-mall companies, like I had to, to get the real DEXA scan. I paid $70. I think they even have, you know, holiday sales or whatever.

Now I want to do it again, because I did that just at the beginning of my kind of strength training campaign. I'm the strongest I've ever been in my life. I want to see how much muscle I’ve built. So it's like you say: Aging with strength. And it's an amazing difference.

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AGING with STRENGTH: Can I ask you quickly about BMI? Obesity rates in the United States have gone through the roof — 40% of American adults are now considered obese. But obesity is based on BMI, which, as you mentioned, is a bad test because it doesn't distinguish between fat and muscle. So isn't that 40% rate false also?

Eric Topol: Yeah, it's off.

AGING with STRENGTH: So is there less of an American obesity problem?

Eric Topol: Well, we don't know. It could be more. It's probably less because you've got these athletic people that have big muscle mass and their BMIs are 30.

AGING with STRENGTH: I want to get to something you and your book say is extremely important to understand: the brain-gut axis. What is it and why is it important?

Eric Topol: Only in recent years have we gotten fully in touch with the many ways that the gut talks to the brain and vice-versa. Parkinson's disease has long been thought to emanate from the gut, not the brain, and there's more and more data to substantiate that. But that's just one aspect.

There's direct nervous system connections like the vagus nerve that goes from the gut sensory neurons right through the brain stem. The gut hormones actually talk to the brain directly.

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What is amazing is how gut hormones talking to the brain modulate inflammation and change the reward circuits in the brain. So people don't just lose weight, they markedly curtail alcohol, cigarettes, gambling — anything they're addicted to. Their reward circuits get rewired. They eat healthy food. They not only eat less food, they don't want to eat the junk they were eating.

Now we know there's this dramatic shift in the inflammation and the immune system from the gut hormones. There's a whole chapter on the immune system in the book. We learned how the brain is mission control for the immune system. We've also learned that the two [organ aging] clocks — the brain clock and the immune system clock — those are the two clocks to pay attention to, because that is healthy survival2, right there.

If I only could have two [organ aging] clocks, those are the two I want. And, by the way, those will be available in the next year.

AGING with STRENGTH: Organ aging clocks for the brain and the immune system?

Eric Topol: Well, for all eight [organ aging clocks], but brian and immune are my top two. I just met with the guy from the company [doing this], and he wants to get it out for $100. They test up to 11,000 proteins, and then the AI partitions out which proteins matter for each organ. I mean, it's the real deal. I'm glad it's going to be inexpensive. It's going to be routine someday. It's our first gateway window into our immune system and it's an invaluable marker of our brain's pace of aging.

These are tests for the gut-brain axis. Now, what is interesting is they've started trials, and are almost done with Ozempic, to prevent Alzheimer's in lean people, not obese people. It would have been even better if they did trials with people who had accelerated brain [aging] clocks.

This gut hormone connection [to the brain] is one of the biggest shifts in our understanding of the biology of humans. These are center stage now. It's not just the science part of aging, it's that we can manipulate them, we can mimic them, we can block them, you know. The point being, the way to a person's brain and to healthy aging, will likely be through their gut.

AGING with STRENGTH: That's the money quote!

Eric Topol: Yeah. Who would have guessed? The immune system is so entangled, so intertwined with what's going on in the gut. I mean, would I have ever thought that was possible? Never.

AGING with STRENGTH: On page 225 of the book, you write that "someday there will be a place for heritable human genome editing." How do you think about human genome editing and the ethics around designer babies?

Eric Topol: I'm not keen on embryo editing, especially with the misdeeds we've seen. But I do think eventually we'll get there. It starts to become the changing of humans. I'm much more excited about taking the somatic genes we have and doing that for preventing these three diseases. So, for example, if I'm an APOE4 carrier, can I have my APOE4 turned into APOE2?

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That'd be great because my chance of Alzheimer's would go way down. And as I mentioned in the book, there's already work being done to do that in people.

And then what about risk of heart disease? If I could just get a shot, a PCSK9, it works in the rare disease of familial hypercholesterolemia and I never have to take a drug the rest of my life because it prevents heart disease. I’d say, "I'll take that."

So I'm much more keen on the common diseases that will be approached by genome editing than I am about the embryos, because it's much more dicey.

AGING with STRENGTH: I'm barely keeping up with you on this stuff. Average folks who wants to be healthy, who are 50 and have a busy life — where can they go to learn more about all the acronyms?

Eric Topol: I think the new AI searches are great. So you could go to Perplexity. You could go to Gemini and Claude. Not only has that really gotten so good now but it also will be very current. A lot of these things are constantly evolving. So that's how I get good information.

AGING with STRENGTH: Can I ask you about intermittent fasting and/or calorie restriction? I know these are different things. Is either a longevity helper?

Eric Topol: There's no data to support it, including the guy at USC.

AGING with STRENGTH: Valter Longo?

Eric Topol: Yeah, but it’s data on mice and yeast, not people. That's the problem with all these. They look really good in rodents, but we don't have the data for people. He may be right, but we don't have any good convincing, even remotely compelling data. Now, is it good for weight loss? Yeah. It works well for weight loss. And if you keep your weight off and you avoid obesity, that should be good. Most people can't do that. A lot of people swear by it.

But the smart thing would be to eat your evening meal and don't eat anything else until the morning. They might help to extend health span, but we have no evidence.

AGING with STRENGTH: I’ve seen doctors advocate for the fast-mimicking diet, saying that science clearly shows that after a 72-hour fast the body starts cleaning out the zombie cells. Is that b.s.?

Eric Topol: It's just not adequate evidence to make a call on. I always worry when you publish some work, and then you have a company selling based on that publication.

That's what Peter Attia has done with his Biograph company. His book was pretty good, with a few caveats that I worried about. I had talked to him about that, but then he's gone off and done this. The guys at USC? Just do the science, okay? Don't make a company out of it, or go ahead and make a company, but not dependent on the science papers.

AGING with STRENGTH: You’re saying separate your research interests from your financial interests; otherwise, you lose your credibility?

Eric Topol: Because then you say, well, that paper that you had in Science [magazine] where it really wasn't compelling, it was suggestive, and now you formed a company and you're selling it. They don't have the sine qua non, the nuts of the evidence. And now they're going to sell it. If you're going to start a company, do it on something that has evidence.

AGING with STRENGTH: I’d like to ask you about alcohol. There's been a lot of things written in the last several months about alcohol being entirely bad for you, regardless of amount. And then, more recently, I wrote about an NYU researcher who attempted to quantify how much drinking actually takes off your lifespan. She said the data is a bit murky, but that number might be 1.8 years per alcoholic drink per week.

Eric Topol: That's interesting. Here's the big problem: With alcohol, we're trying to treat all humans the same. That's really dumb. Because if it has a risk for a cancer — for example, all three [recent government] reports did agree that there's a breast cancer risk when you pass a certain threshold. But 88% of women never get breast cancer. Only 12% of women ever get breast cancer in their life. So those are the people that need to be in the alcohol worry category.

No recommendation can be prescribed for all human beings. We keep coming up with these cockamamie assertions — "alcohol causes eight different types of cancer." Well, guess what? It doesn't just cause the cancer by itself. You have to have a genetic predisposition to those cancers. If I give the same amount of alcohol to 100 people — big-time alcohol — only one might develop esophageal cancer. And guess what? That person had a genetic predisposition.

AGING with STRENGTH: I don't think people understand that.

Eric Topol: But that's the thing: people should know if they're at risk for something, and these recommendations should be much more specific than, “Here are the Ten Commandments for the human species.” That just doesn't work anymore. We're smarter than that.

AGING with STRENGTH: What keeps you up at night?

Eric Topol: What keeps me up is, we're chasing our tails, we're taking away all the funds from doing the research that we need. I mean, currently right now with this administration, we're gutting resources. We're throwing people out who we need, whether it's at NIH, FDA, CDC, HHS — the whole works.

We're not taking on the environmental toxicities that we have to take on, which this administration, at least RFK Jr., has acknowledged is important — ultra-processed foods, plastics, forever chemicals, air pollution, we're doing nothing. In fact, the climate crisis is intertwined with all these, and we're not addressing that. We're denying it.

We're not looking after our less-privileged people, underrepresented people who should have access to all these things, and they're the ones who need it the most, and they're the ones who have the worst air pollution, the most microplastics, the most ultra-processed food, et cetera.

We have this monumental, phenomenal opportunity to prevent the three biggest diseases of humans that curtail our health span, and then at the same time, the things that are holding us back we're in denialism or we're ignoring.

We can't get the big jump in progress without putting the priority and the resources on the things that are holding us back. Our exposure to these toxins and these things in our foods that Big Food has never been taken on. They just keep getting away with it.

The people that need this stuff the most, all these longevity companies don't give a hoot about them.

I care about these people. I want a solution that's inexpensive, that AI... AI is not expensive. It's software, basically. You know, I want this free intelligence for medicine, for health.

AGING with STRENGTH: Anything that I should’ve asked you about but didn’t?

Eric Topol: I think you got it covered. It's been an extensive discussion.

It's a much more exhaustive interview than I expected. What's great is you've been thinking about it a lot. So that's why you are way ahead of the curve.

Eric Topol is a cardiologist and one of the top 10 most cited researchers in medicine. I sat down with him for an in-depth interview last month to discuss the biggest takeaways from his best-selling book, “Super Agers: An Evidence-based Approach to Longevity,” which quickly became a New York Times bestseller.

I’ve distilled our 70-minute conversation, which took place in Dr. Topol’s office at Scripps Research Translational Institute, which he founded, in La Jolla, Calif., into the Q&A below.

This is Part 1; I’ll publish the second and final part of the interview next week. Dr. Topol called our conversation “exhaustive” — a compliment, considering most media interviews he’s done have only skimmed the surface of his book’s scientific strategies for achieving a healthy and vigorous life free of physical, emotional and cognitive diseases — aka, aging with strength. There’s a lot to learn from Dr. Topol, below.

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(This interview has been lightly edited for clarity and length.)

Paul von Zielbauer, AGING with STRENGTH: Dr. Topol, you’ve written a few bestsellers, but until now none specifically about aging. Why did you write “Super Agers”?

Eric Topol: Each of the books I had done previously were trying to look at, “What's the next big thing in medicine?” “Super Agers” is about forecasting for each person to prevent the Big Three diseases of our species: cancer, cardiovascular disease and neurodegeneration.

The book's intent was to lay out that, while there's all this stuff going on to reverse aging, and that may be great someday, it's going to have risks.

On the other hand, there's this great promise that no one is really working on, using the science of aging to understand each person's aging process. There's all these biomarkers. I did the book primarily to anticipate where aging [science] has yield and excitement.

The other big reason was my longstanding interest in health span, healthy aging and the "Wellderly" — the people in their late 80s who have never had a chronic illness.

And then finally…we have these companies that are selling longevity, we have anti-aging supplements that don't do anything, we have Bryan Johnson and all these quacks. So we need the real truth out there, the facts. And I said, “Well, I can try to project where we can go and get the story straight.”

It's been really terribly predatory out there.

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AGING with STRENGTH: You are appropriately aggressive at calling out the longevity charlatans and chiselers out there — Andrew Huberman, David Sinclair, Peter Diamandis, you mentioned Bryan Johnson.

Eric Topol: Peter Attia is on that list, too.

Paul: David Sinclair, a notorious longevity chiseler, has claimed that aging is a disease that can be reversed. Do you believe that aging is a disease?

Eric Topol: That's a really great question. Aging is a normal process, so it's hard to call it a disease. (We used to say obesity wasn't a disease, and now that we have a treatment for it, we say it's a disease.)

The question is, Is it the root of the three major diseases? Are most of the cancers and the cardiovascular and neurodegenerative diseases an outgrowth of aging? They're dependent on the aging process. So I don't think aging itself is a disease, but because of the way it affects our immune system — the buzzword on that is immunosenescence — and the way it increases our propensity for inflammation, "inflammaging" — those two interrelated processes of aging — [aging] basically invites diseases. It sets up for disease. So per se, no, but indirectly, yes.

AGING with STRENGTH: You get to that at the end of your book, where you say immune function is one of the mainstays of remaining healthy deep into old age.

Eric Topol: We did that study, the "Wellderly" study, of 1,400 people age 80 years and older who had never been sick. No medications. Yet their families mostly did not have that pattern. Lea Rosenberry was 98. Her parents died in their 50s and 60s. Her brothers died in their 60s, and yet she's 98 and perfectly healthy. That was the pattern we saw in the “Wellderly” study.

So what is the explanation for that, if it's not in their DNA? My bet is it was these people's immune system, which is unlike most of us as we get older, where we lose our fine tuning, the integrity [of our immune function], so it’s more vulnerable and it allows cancer cells to get going and spread, or it's untoward inflammation in our brain, in our body, in our arteries that sets up the other two diseases.

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So it's the immune system. I keep saying to myself that old thing about the economy: “It's the immune system, stupid!” Because it really is. And only now are we seeing the beginnings of our ability to assay comprehensively a person's immune system.

We should be having immune system testing as we get older, because it is the reason why aging can hurt us.

We don't have a test for it in the clinic. We have a stupid test, which is in your complete blood count, the ratio of your white blood cell neutrophils to your lymphocytes. It's basically worthless. That's the only thing we have today that tells us anything about a person's immune system.

We have this emerging thing called organ clocks, which I'm very excited about. There's also an immune system clock. But that's just [measuring] proteins and it may not be a very accurate window to the cellular component — the antibodies and the interferons.

The immune system is so complex and it [represents] the big hole in the story of extending health span. We have to be able to test people starting at age 50, 60, 70, especially the older they get. Because we have ways to control it. We can dial it up and down. We just don't know who needs to control what.

AGING with STRENGTH: Along with creating a robust immune system later in life, how should people over 50 think about keeping their organs young? And which ones should they focus on?

Eric Topol: First, you’ve got to find out where the vulnerability is, which organ, and then you can get all over it. Let's say it is the immune system, and you have a family history of cancer but you don't know what type of cancer. You do a polygenic risk score.

We have that for every common cancer.

Everyone should have a polygenic risk score for the major cancers. I mean, it's inexcusable, for example, that we have an American president [Joe Biden] who goes all these years, and then all of a sudden has Gleason 8 prostate cancer, which almost invariably would have shown up [on a polygenic risk score test] that he was at high risk — and it was never done.

We do screenings based on age. It may not be just age. It may be, “What do you know about your family?” You get some genetic assessment, whether it's whole genome sequencing or polygenic risk score, then you start to look at the protein layer and particular biomarkers. And if you do have a high risk for cancer, and your immune system is down, but there's no evidence of cancer from, say, a multi-cancer early detection test, a blood test, then you could just keep an eye on this immune system and rev it up.

We just saw how if you just give shingles vaccine to people, it reduces the incidence of dementia and Alzheimer's by 20, 25 percent. If that was a medicine, that would be huge. It basically just revved up the immune system so that their ability to deal with the amyloid and tau proteins and these misfolded proteins in their brain. It just gave them a better defense.

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AGING with STRENGTH: Your book documents the big pillars of maximizing health span: Exercise, muscular strength maintenance, sleep, balance, nutrition, community and environmental factors, which the book calls “Lifestyle +.” How else should people think about maximum longevity?

Eric Topol: When you talk about nutrition, you’ve got to [consider] alcohol and salt and sugar. And then social interaction and being in nature. I was surprised at the body of evidence on these things. I didn't expect it. The environment, being in nature. And then along with that are the adverse things in our environment to try to minimize, whether that's [poor] air quality in your home or workplace or it’s plastics. And within nutrition, [limiting] ultra-processed foods and the forever chemicals.

The ultra-processed food story is pretty striking. And then these new categories, like you're bringing up, the social engagement, the beauty of the impact of being out in nature, for mental health.

AGING with STRENGTH: Longevity science can quickly get esoteric and technical, discussing ApoB, metformin, rapamycin, GLP-1s, polygenic risk scores, genomic sequencing, DEXA scans, SGLT-2 inhibitors. How should non-scientists figure out what they need to understand in order to maximize health span?

Eric Topol: On the one hand, it would be great if everybody adopted all the things we know about “Lifestyle +.” If everyone endeavored to do all that, we'd be way ahead in prevention. As outlined in the book, 80 percent to 90 percent of heart disease is preventable; 50 percent or so of cancers and neurodegeneration are preventable with what we know today. But most people don't do all these [preventative] things. So one of the [book’s] missions was, “Let's go with everything that's out there that we know to prevent.”

The problem is when you tell people to do all these things, most people don't do them.

So you don't just tell them, because it doesn't work. I mean, you try. As a doctor-patient relationship, I try. And some people will make a lot of big changes. But what I've learned, and what studies bear out, is that you can particularize the plan for a patient's risk — for example, heart disease — and that's what you go after. And that’s why you check these extra lipid tests like LP(a) and ApoB. And get you off red meat as much as possible and get you on an anti-inflammatory diet. For that person, you have a plan that uses a lot of that lifestyle [factors] but it’s much more directed.

Each person has a different strategy. For the people with cardiovascular, we're going to get the LDL down, whatever it takes, to very low levels. We're going to get LP(a) down. We're going for broke to prevent that disease.

For cancer, we're going to go into this early detection. We're going to get it at the microscopic level. We're going to keep your immune system high integrity so you don't even get microscopic cancer, because we've learned it's all about the immune system, why people get metastatic cancer.

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And then for Alzheimer's, [there is] a biomarker called p-tau217. We've got the polygenic risk score for Alzheimer's. We've got the ApoE4 allele. So, for you, today, I could say, you have a high risk or don't have a high risk, and I can say when. I never could say that before. Before, I could say only, "We're going to do a polygenic risk score, and it says you are high risk for Alzheimer's. But we don't know if that's when you're 102 or when you're 62.”

Now we can say it's at 87, plus or minus two years, when you will have mild cognitive impairment. And then another few years before you develop full-blown Alzheimer's. So we are so much better positioned now with AI. And none of this could happen without the AI.

Because you're taking all these data points, billions for each person — everything in the electronic [health] record, unstructured text, all their lab values, where we say, “Oh, it’s normal, no issues,” but the AI sees the trend among normal lab values. AI sees in the image things that humans will never see. And you have all this assembled and then you say, “This is what we're going to work on for this person.” We have this lifestyle plan and, oh, by the way, the GLP-1 drugs, like Ozempic? That could be a big winner for preventing Alzheimer's.

AGING with STRENGTH: GLP-1s — glucagon-like peptides — seem to be an emergent class of wonder drugs. Ozempic is the one that gets most of the attention in the longevity conversation, but what should my readers understand about how GLP-1s may impact their health spans?

Eric Topol: Glucagon-like peptide is one of the gut hormones that we're mimicking with injectable peptides. GLP-1 is just one of the three hormones that are now into therapeutics, or at least a third receptor is. There's glucagon and there's GIP, which is the gastric inhibitory peptide, and then there's 15 more. The dual receptor, which is tirzepatide, has been shown to be much more powerful than Ozempic for weight loss.

But then there's another 15 more peptides that people don't even know about that are coming. But with just GLP-1, that one peptide, if you're obese, you lose weight but before you lose one pound, the inflammation in your body and your brain comes down. I mean, it's striking.

Now we know that the principal action of these drugs, or a big driver, is markedly reduced inflammation.

Some of these newer peptides that are going to be the next-gen, they are incredibly well at penetrating the brain, [via] the vagus nerve. So they'll have even more anti-inflammatory effect in the brain than we've seen with Ozempic.

So this is very exciting. When I say this is a miracle drug class, I'm not just talking about that first one, GLP-1, which took 20 years to figure it out, but about…

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In this Fun Friday short post, four brief explorations of thoughts that came to mind while doing the dishes this week.

1 | Longevity chiselers and anti-aging charlatans

When I launched AGING with STRENGTH almost nine months ago, it didn’t take the YouTube algorithm very long to feed me a steady diet of Andrew Huberman videos discussing the notion that aging is a disease that can “halted.” By casually infusing his plain English explanations with just enough scientific jargon, Huberman, a Stanford neuroscientist, often asserts unproven theories as fact. He also has a financial stake in products and services he recommends, though he doesn’t often disclose them.

Huberman appears to be what I call a longevity chiseler:

lon·​gev·​i·​ty chis·​el·​er, n. someone who intentionally promotes unproven anti-aging claims or misrepresents facts for financial gain, often unacknowledged.

Huberman is chummy with another longevity chiseler, David Sinclair, a Harvard geneticist who once claimed, falsely, that he and his colleagues had figured out how to reverse aging in dogs. Together, they exemplify the art of scientific misinformation.

The market for preventive wellness, supplements, diagnostics and related healthspan-extending interventions is expected to surpass $8.5 trillion by 2030. With that much money in play, expect a growing number of longevity chiselers and anti-aging charlatans to pop up on your YouTube feed, too.

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2 | A European vacation with my mom and daughter

Next week will be a big one for me: I’m taking my 82-year-old mom and 9-year-old daughter to Austria, Switzerland and Bavaria, for an three-generation, train-based European vacation.

This will be the first and likely the last time we three travel together, so I’m looking forward to this experience, and especially the privilege of watching mom and daughter have their own European travel experience, together and individually.

I’m betting many of you have done something similar with parent and child together on a vacation or extended outing, so I’m asking for advice: What do I need to know that I’m not anticipating? Any helpful thoughts welcome.

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3 | Becoming a “super ager,” Part 2: don’t sleep too much

Last week, I mentioned I’d interviewed Dr. Eric Topol, one of the world’s leading medical researchers and author of “Super Agers.” Here’s another interesting finding from the book: regularly getting more than 7-8 hours of sleep a night is associated with a 12-percent greater risk of cardiovascular disease.

If you have a few hours to spare, here’s the research behind that statistic.

I’ll write a full post about my 70-minute interview with Dr. Topol. After I return from Europe, most likely.

4 | Two upcoming podcasts you’ll want to watch or hear

In the next two weeks, I’ll also publish edited versions of video conversations with two people who have a lot to say about different aspects of aging with strength, with some surprise moments:

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GLP-1, Metformin and rapamycin: three names that keep cropping up in the modern longevity conversation. Below is a brief but detailed breakdown of each of these three…things (they’re not “drugs” and I’m not sure there’s a single word that accurately comprises all three). Here’s a bulleted introduction to each thing, and below I get into what they do, the necessary cautions and the bottom line for each:

Disclosure: I used AI tools to research the information below, checking sources and facts for accuracy. Oh, and in case you missed it:

Check out this week’s 2-minute #WorkoutWednesday:

I’ll post more 2-minute mini-workouts for paying subscribers, keeping the regular #WorkoutWednesday open to all. Paying subscribers will also soon get access to other exclusive posts, including brief, but intense, #GymDad video workouts.

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GLP-1: An emergent wonder anti-aging and longevity drug?

Glucagon-like peptide-1, or GLP-1, is a hormone your body naturally produces, mainly in your gut, in response to eating. Its main job is to help regulate blood sugar by prompting your pancreas to release insulin (which lowers blood sugar) and by reducing the release of glucagon (which raises blood sugar). GLP-1 also slows down how quickly your stomach empties, which helps you feel full longer and can reduce how much you eat.

GLP-1 and aging: How does it affect longevity?

Recent research indicates GLP-1’s influence goes far beyond blood sugar and appetite control. Scientists are now exploring how GLP-1 and drugs that mimic its action (called GLP-1 receptor agonists) might help slow down aging and extend healthy lifespan.

Here’s what’s emerging:

• Cellular protection: GLP-1 appears to protect cells from damage caused by oxidative stress and chronic inflammation—two key drivers of aging and age-related diseases.

• Molecular rejuvenation: In animal studies, GLP-1 drugs have reversed many age-related changes at the molecular level, including improving the function of genes and proteins involved in cell repair, energy production, and metabolism. These effects were especially noticeable in older animals, not young ones, and occurred even without significant weight loss.

• Brain and body benefits: GLP-1 may help protect the brain from age-related decline, improve memory, and reduce the risk of diseases like Alzheimer’s. It also seems to benefit the heart, kidneys, and bones, all of which are vulnerable as we age.

• Potential for longer healthspan: Because GLP-1 drugs can reduce risk factors for chronic diseases (like diabetes, heart disease, and possibly neurodegenerative diseases), they could help people stay healthier for longer as they age.

How does GLP-1 work?

GLP-1’s anti-aging effects are thought to come from its ability to:

• Boost the body’s natural repair mechanisms (like DNA repair)

• Improve how cells handle stress

• Reduce harmful inflammation

• Support healthy metabolism and energy production in cells

What’s the evidence?

• Animal studies show promising results for reversing signs of aging at the molecular and functional levels.

• Human studies are ongoing, but early evidence suggests GLP-1 drugs can help manage or prevent several age-related diseases, potentially expanding healthy lifespan.

GLP-1 risks

While GLP-1 drugs are generally safe, especially for people with diabetes or obesity, they can cause side effects like nausea or, in some cases, loss of muscle mass, which is a concern for older adults.

The bottom line re GLP-1s

GLP-1 is a hormone that helps control blood sugar and appetite and is now being studied for its potential to slow aging and extend healthy years of life. By protecting cells, reducing inflammation and improving metabolism, GLP-1 and its related drugs may offer new ways to combat age-related decline and diseases.

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Metformin: A diabetes drug with anti-aging potential

Metformin is a widely prescribed medication for type-2 diabetes, first synthesized in 1922 and FDA-approved in 1994 (72 years later!). Derived from the French lilac plant, Metformin is known for lowering blood sugar by reducing glucose production in the liver and improving insulin sensitivity. Recently, scientists have explored its potential to slow aging and extend healthy lifespan.

But fair warning: Bozos like David Sinclair, who has repeatedly been called out by his peers for overstating if not fabricating clinical results of longevity research, are also behind glossy, overly optimistic reviews of Metformin, like this one.

How Metformin Works

• Blood sugar control: Blocks liver glucose production and helps muscles absorb sugar more efficiently.

• Activates AMPK: A cellular “energy sensor” that improves metabolism and reduces oxidative stress.

• Anti-inflammatory effects: Lowers chronic inflammation linked to aging and diseases like heart disease and Alzheimer’s.

Metformin & longevity

• Healthspan: Strong evidence shows metformin extends years of healthy life by delaying age-related diseases:

  • Reduces cardiovascular disease risk by improving blood vessel health.

  • Lowers cancer risk in diabetics and may protect against cognitive decline.

  • A 2024 study in monkeys found metformin reversed molecular aging markers (e.g., reduced inflammation, improved DNA repair) in multiple organs, effectively making their tissues 6 years “younger.”

• Lifespan: The evidence is mixed:

  • In mice, metformin extended lifespan by 14% when started young, but had minimal effects in older mice, a 2013 study found.

  • Human data from diabetics suggest longer lifespans compared to non-diabetics, but it’s unclear if this applies to healthy people.

Metformin controversies and risks

1. Does it work for healthy people?

   • Benefits may depend on existing metabolic issues. Studies in disease-free individuals show inconsistent results.

   • Critics argue its anti-aging effects are indirect, stemming from better blood sugar control rather than directly targeting aging pathways.

2. Side effects

   • Common: Nausea, diarrhea, and stomach pain (especially when starting the drug).

   • Vitamin B12 deficiency: Long-term use can lower B12 levels, raising anemia and nerve damage risk.

3. Age-dependent effectiveness

   • In mice, metformin’s benefits diminished when given later in life. Which raises questions about its utility for older adults.

4. Dose matters

   • High doses (1% of diet) were toxic in mice, while low doses (0.1%) extended healthspan. Human dosing strategies are still being refined.

The bottom line re Metformin

Metformin shows promise for extending healthspan by preventing diseases like diabetes, heart disease, and dementia. But its ability to increase lifespan, especially in healthy individuals, remains uncertain. It’s generally safe for diabetics but its side effects and variable effectiveness in non-diabetics mean proceed with caution.

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Rapamycin: Wonder drug found in Easter Island dirt?

Rapamycin (also called sirolimus) is a natural compound discovered in 1964 (the baby boomer of longevity wonder drugs) in soil from Easter Island (aka Rapa Nui). Originally used to prevent organ transplant rejection and treat cancer, it’s now being studied for its surprising potential to slow aging.

What Rapamycin does

• Targets mTOR: Rapamycin blocks a protein complex called mTOR, which acts like a control center for cell growth, metabolism and aging. By slowing mTOR, rapamycin helps cells focus on repair and survival instead of growth.

• Extends lifespan: In animals, rapamycin increases lifespan by 10% to 15%, even when given later in life. It delays age-related diseases like cancer, Alzheimer’s and heart disease by reducing inflammation and clearing damaged “zombie cells.”

• Animal studies: Mice given rapamycin live longer and stay healthier, with stronger hearts, better immune function, and fewer tumors. But mice aren’t people….

• Human potential: Early trials suggest it may improve immune health in older adults and treat age-related conditions like gum disease.

Rapamycin controversies and risks

• Immune suppression: At high doses (used in transplants), rapamycin weakens immunity, raising infection risks. However, low “anti-aging” doses may modulate immunity — calming overactive responses while preserving defenses. Critics argue even low doses could increase infection susceptibility in vulnerable people.

• Metabolic side effects: Can raise cholesterol and blood sugar, potentially worsening heart disease risk if unmanaged.

• Long-term safety: No long-term human data exist for anti-aging use. Critics question using it without proven benefits in healthy people.

Current Rapamycin research (2024–2025)

• Human trials: Testing rapamycin for age-related muscle loss, immune decline, and Alzheimer’s.

• Combination therapies: Pairing rapamycin with exercise or other drugs to maximize benefits and minimize risks.

• Senolytics: Newer anti-aging drugs that clear zombie cells are being compared to rapamycin for effectiveness.

Should you consider Rapamycin?

• For healthy adults: Experts are split. Some take low doses off-label, citing animal data and small human studies. Others, like U.C. Berkeley’s Dr. Andrew Dillin, quoted in this New York Times article on rapamycin, thinks not: “Why take risks with unproven benefits?” he told The Times. “I’ll pass.”

• For older adults: May help reverse immune aging, but requires close monitoring for infections and metabolic changes.

The bottom line re Rapamycin

Rapamycin is a promising but controversial anti-aging candidate. While it shows remarkable potential in animals, human risks and benefits remain uncertain. Current trials will determine if it’s a true longevity breakthrough or a risky gamble.

Whew! That was a lot of information. I hope it’s helpful to you.

On Monday, Harvard’s School of Public Health announced new research that reveals — are you sitting down? — that healthy eating in midlife is linked to healthy aging.

Yes. Several media sites ran with this mind-blowing news while failing, in a stark example of how rote health journalism is nowadays, to notice the disturbingly unhealthy aging revelations that lay further down in the researcher’s findings.

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What the new Harvard research says

Before I get to those, some quick context:

In a paper published in Nature Medicine, 13 researchers from Harvard and the universities of Montréal and Copenhagen concluded that people who maintain diets that includes more plant-rich foods have a greater chance of living into their 70s than people who eat more ultra-processed foods and red meat.

The research does include several genuinely interesting insights into the diets, and specific foods and beverages, that it associated with greater or lesser chances of remaining healthy after 70. (See chart below for more detail on those foods.)

• The study examined data from 105,000 Americans, aged 39 to 69 (two-thirds women and ~95% white) who self-reported detailed dietary consumption every 4 years over the course of 30 years, from 1986 to 2016. This is a significant longitudinal data set, spanning decades, though one lacking demographic variety.

• Researchers categorized participants’ self-reported eating and drinking regimens into eight healthy dietary regimens that included large amounts of fruits, vegetables, whole grains, unsaturated fats, nuts and legumes. All the dietary regimes, except for the vegetarian diet, also included meat, fish and certain amounts of ultra-processed food and red meat.

• The dietary regime that was most greatly associated with “healthy aging,” which the study defined as reaching age 70 with no cognitive, mental or physical problems or chronic disease, was the Alternative Healthy Eating Index (AHEI).

• The strictly vegetarian diet had the weakest association with “healthy aging.”

• Also: All 105k study participants were nurses and other health professionals.

For further details on the study, here’s a servicable Washington Post article.

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What The Post, NBC News and the rest of the media missed

So here’s the dark surprise in this Harvard study that hasn’t been reported elsewhere, as far as I can tell: Though this research purports to show which dietary regimen promotes healthy aging, the vast majority of this massive cohort of 105,000 health professionals did not age well and, in fact, hit age 70 in demonstrably poor health (see screenshot below):

1. Only 9.3% made it to 70 with “intact” cognitive, mental and physical function and no chronic diseases. (There’s a pronounced gender gap: though 11% of women in the study hit 70 in all-around good health; only 6% of men did.)

2. Only 38% — barely a third — managed to survive to 70

3. Fewer than 1 out of 4 managed to avoid contracting a chronic disease

4. Only a third reached 70 with full cognitive function; fewer than a third had “intact physical function”

5. Only about 1 in 4 study participants had a clean bill of mental health by 70

Here’s the upshot:

• A study of a huge number of healthcare professionals from the 1980s, 1990s, 2000s and 2010s who ate mostly plant-based diets reveals that few of them made to 70 in good health. Nearly two-thirds didn’t even make it 70, though cohort life expectancy1 for men and women of that generation was 73 and 79, respectively. Maybe healthcare workers are more likely to be unhealthy (due to stress and compensatory behaviors like smoking and drinking, say, or to exposure to illnesses). The published study is silent that topic.

• But consider the implications: If the contemporary average life expectancy2 for a white American woman and man is 80 and 75, respectively (the study participants were overwhelmingly white), is it reasonable to assume that most Americans still breathing at 70 are not, and will not be in the future, in particularly good health?

  AUTHOR’S EDIT: As an AGING with STRENGTH reader pointed out after this article first published, mine may be an “apples to oranges” comparison, because life expectancy for white American women and men between 1947 (when the oldest people in this study would have been born) and today has increased by 14% and 17%, respectively. However, what is known as “cohort life expectancy,” explained in Footnote 1 below, shows that these 105,000 health professionals would have a life expectancy well above 70 years. Moreover, two-thirds of the people in this study cohort were women, who, if you believe the Social Security Administration’s life tables, would have had a life expectancy of 78.

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• What do these numbers say about the prospects of people now in midlife reaching, or living beyond, the rather young age of 70 without a chronic disease or significant cognitive, emotional and physical problems? During the ~75 years since many of the people in this study were born, American obesity rates for white men and women have exploded at least 4x, from under 10% at mid-century to 38% today. These rates, as well as those for severe obesity, have gotten only worse since 2016, when the data for this study concluded.

A “healthy aging” food and beverage chart worth reading

The Harvard study also includes a chart (see below) of foods and beverages that illustrates the associations between individual dietary factors and the researchers’ definition of “healthy aging.”

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Some of this information is intuitive. For instance, larger consumption of fruits, whole grains, vegetables, added unsaturated fats, nuts, legumes and low-fat dairy were associated with greater odds of healthy aging. Likewise, greater consumption of trans fats, sodium, total meats, including red and processed meats, were associated with lower odds. But then there are some counterintuitive results as well.

Below the chart is a simple explanation of how to read it.

Interpreting the chart’s colors

Green squares show foods that are good for healthy aging — they increase your odds of aging well. Pink/red squares show foods that are bad for healthy aging — they decrease your odds of aging well. Darker colors (either green or pink) mean stronger effects. Lighter colors mean weaker effects. White/blank spaces mean no significant relationship was found. Asterisks (*) indicate findings that are statistically significant.

The chart’s main takeaways

This chart suggests that a primarily plant-based diet with moderate amounts of select animal products (like fish and low-fat dairy), healthy fats and minimal processed foods, red meat and added sugar would provide the best chance for healthy aging.

Several other findings that may strike you as either interesting, affirming, counterintuitive or utter crapspackle:

1. Fast food is…sorta healthy? There are several possible explanations why the "Fast and fried foods" row in this chart are green. The study’s authors suggest that people who occasionally eat out might have stronger social connections, which are known to positively influence longevity and health.

2. Eggs show mixed effects. Eggs appear to have a neutral to slightly positive effect on physical function and mental health, despite years of concern about their cholesterol content. This aligns with more recent research suggesting eggs may be healthier than previously thought.

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3. Coffee has varied effects. Coffee shows a negative association with cognitive function but positive associations with mental health and survival to 70 years of age. This mixed pattern might explain conflicting findings about coffee in previous research.

4. Pizza shows some positive associations. Similar to fast foods, pizza has some green squares (particularly for healthy aging overall), which seems counterintuitive for what's often considered an unhealthy food.

5. Potatoes have mixed effects. Potatoes show negative associations with some aspects of healthy aging but positive associations with others, despite often being grouped with other vegetables.

6. Snacks have positive associations. The "Snacks" category shows several green associations, particularly with survival to age 70 — unexpected for what most people would consider less healthy foods.

7. Dietary pattern effects were stronger in women. The study found that the associations between dietary patterns and healthy aging were consistently stronger in women than in men.

8. Stronger benefits in higher-risk groups. Dietary patterns showed stronger associations with healthy aging among smokers, overweight individuals, and those with lower physical activity levels, suggesting diet may have more impact in higher-risk populations.

9. Dairy products show mixed effects. Low-fat dairy shows positive associations while high-fat dairy (including butter) shows negative associations, reinforcing the importance of distinguishing between different types of the same food group.

10. Participants in the highest quintile for the the following diets — the Alternative Healthy Eating Index (AHEI); the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND); the healthful plant-based diet(hPDI); and the Planetary Health Diet Index (PHDI) — consumed more alcohol than those in the highest quintile for the Dietary Approaches to Stop Hypertension (DASH) and Alternative Mediterranean Index (aMED).

Altogether, the research highlights the complexity of nutrition research and reinforce that the relationships between foods and health outcomes aren't always as straightforward as commonly believed.

Building nutritional strength for yourself: pick and choose

The study authors said their findings, and this chart, are best used not as a set of rigid rules but as guidance that people can use to build a dietary plan that fits their specific goals. I plan to reach out to them, to follow up on the “dark surprise” statistics surrounding the paucity of participants who managed to get to 70 in good health.

I’ll let you know what the researchers tell me, if they respond. But let’s also keep sight of the practical wisdom here.

As Anne-Julie Tessier, an assistant professor of nutrition at the University of Montréal and the lead author of this study told the WaPo: “This suggests what you eat in midlife can play a big role in how well you age.”

Let’s hope so. But if the low “healthy aging” success rate indicated in this research is accurate, just getting to 70 clinically “intact” may be a bigger challenge, with a lower likelihood, than any of us had thought.

What are your expectations for “healthy aging”? Leave a comment.

A few days ago, I spoke with Dr. Michael Snyder, a prominent Stanford geneticist and the senior author of a blockbuster-esque study that the Stanford press team and several major media organizations said, incorrectly, showed that all people age more rapidly around ages 44 and 60. I reviewed that research critically in an Oct. 12 post. Below is my exchange with Dr. Snyder, who graciously offered me 30 minutes on a busy Friday while he was in transit. But first….

Mea culpa

I screwed up one thing in my Oct. 12 post: 10 days before publishing it, I had emailed Dr. Snyder’s office to request an interview, to allow him to respond to my pointed questions whether the study’s findings had been significantly overstated by Stanford, the media and, subtly, by Dr. Snyder himself.

Dr. Synder’s office had replied to my request — agreeing to an interview — within hours. He also personally emailed me several times over the following days seeking to confirm a time to talk. Because of my own screw up (I had emailed him from a new email address that I had failed to ensure forwarded to my regular email address, where I would see any reply) I didn’t see his responses and published my article. In that article, I stated — incorrectly, as I now know — that Dr. Snyder and Stanford had not responded to my several requests for interviews. Only a week ago, on Dec. 3, did I discover Dr. Synder’s litany of unrequited replies to my original request. I apologize to him and to Aging with Strength readers.

My Q&A with Dr. Snyder on how his study’s findings were portrayed

The interview, below, shows that there is merit to both the criticism I’ve made of how Stanford and, to a degree, how Dr. Snyder himself portrayed his and his team’s research, about consistent and rapid changes at the molecular level around the ages of 44 and 60. Our exchange also shows a scientist willing to openly discuss his research and, as you will see between the lines, also acknowledge missteps about how it has been portrayed to the public.

Takeaways from the conversation:

• Dr. Snyder’s research paper itself is scrupulous, noteworthy and worthy of discussion; the way Stanford, and therefore the media and, to a limited degree, Dr. Snyder described how broadly it applies to how all people age, was at best less than precise and at worst intentionally inflated, or allowed to be inflated by the media.

• He deserves credit for making himself available for open-ended interviews like the one I conducted with him. He is both accomplished and, from the evidence, quite ambitious, having co-founded seven or more biotech-industry startups that may or may not have an interest in his aging research.

• Only late Tuesday, during my final research for this post, did I learn that Dr. Snyder and his Stanford lab had collaborated with self-help charlatan Tony Robbins to produce questionable research that Robbins now uses to aggressively plug a $4,500 self-help program called Date With Destiny (featuring Dr. Snyder). Robbins even built a new website — scienceofTonyRobbins.com — portraying his program as Stanford-proven to be 100% effective.

Without further kerfuffle, here is Dr. Daniel Snyder, in conversation with me last Friday, about exaggerated claims that all humans age more rapidly at 44 and 60.

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This interview has been edited and condensed for clarity and brevity.

PVZ: Dr. Snyder, it seems to me that the media headlines about your study, and the stories under them, go beyond what the study and the science indicated. Did the media take this ball a little bit too far down the field?

DR. MICHAEL SNYDER: Yes and no. They (journalists) would interpret these bursts of changes as accelerated aging, and I don't think that's what we said. Or least not trying to say.

Most people think of aging as this gradual process where you get older, things gradually change and you die, in a fairly linear process. What we did was look at all the biochemistry. And there's some times when there are more things happening than at other times, in terms of biological processes.

PVZ: I’m looking at the headlines:

• The Guardian: “Scientists find humans age dramatically in two bursts, 44, and 60.”

• Fox News: “Aging speeds up massively at two points in one's lifetime.”

• The Washington Post: “Feeling old? Your molecules change rapidly around ages 44, and 60.”

• CNN: “Humans age dramatically at two key points in their life, study finds.”

These headlines don’t match up with the language that you used in the study.

SNYDER: We're saying that we do see more changes occurring in these 40s and in the 60s relative to the other timeframes. So there are more changes occurring, and we could say exactly what those changes are, at least as measured by blood components.

Whether that's accelerated aging, I don't think we tried to claim that.

I think most news organizations said, “Oh, that means you're accelerating your aging during that time.” And I don't think that was quite our intent.

PVZ: Your study was of only 108 people in and around Stanford — 77% white, 22% Asian, only a few Hispanics and Blacks, studied for 20 months or so and sampled only six to eight times total. Is that enough people, with enough racial and ethnic diversity, studied for long enough to say that all humans age more rapidly around these two ages?

SNYDER: It's true for the population we studied. It remains to be seen how generalizable it is. We tried to be explicit about that, but they don't always print that. So, it remains to be seen if it can be more generalized.

PVZ: You were quoted in USA Today (editor’s note: USA Today actually lifted Dr. Synder’s quote from Stanford’s own press material on this study) saying, “We're not just changing gradually over time. There are some really dramatic changes.” That sounds like you're saying that all humans kind of do this around these two times.

SNYDER: I guess I was trying to generalize, so either I was imprecise — you'd have to read it back to me — but that was our finding. We do see more changes at these two times.

I think it's safe to say from an earlier study that everybody is aging differently. We all have different aging profiles. (The data) are cross sectional, which is the point you're picking up on, meaning we're not seeing one person over many decades to see if those shifts actually occur. We're in the process of collecting another shot of data (across) 11 years. So we will be able to see a better longitudinal side of it. That will take another year to analyze.

But you're right. It's a small number of people. And I think we've always tried to say that is a limitation.

PVZ: I think you say that explicitly in the paper: you can't infer that all humans go through these rapid changes.

SYNDER: Oh, no. And in fact, from our earlier work, we would say that everybody ages differently. Some are metabolic agers, some are cardio, some are immune and some are combinations of those things.

PVZ: It sounds like from the study, and from what you're saying, that people age for different reasons, and maybe they age around 44 and 60, or maybe they don't. But what if people change their lives, or spend a lot of money to change things based on what these headlines trumpet about the inevitability of “rapid” aging at 44 and 60, and it really doesn't help them?

SNYDER: My reaction to that is, I do think (this research) is a heads up, especially as you get towards your 60s. Because what we would say is that that is an average, not on the individual. I would agree with you 100%, so maybe it is misquoted, and I'd have to go back and look at (the article).

So that is an average, that's in our study, and you're right — it is not representative.

But I do think the 60s changes were quite large. That is observed in other studies as well. I do think it is a good heads up. But I think you might say, Well, what's going on in the 40s?

I don't think when you turn 43 you suddenly have all these things happening. My own view — this is hypothesis — is that people get a little more sedentary, other things are happening in their lives, as they go through their 30s. They're generally less active, is my hypothesis. And as they hit their 40s, some of this stuff builds up. But it is a generalization, so you're absolutely right.

It's not every individual — potentially not if they exercise more, they care for themselves, I would hope that those changes in people are minimized.

PVZ: Last question is, and again, I know that you are not the Stanford marketing team, so I'm only asking you because you're the study’s lead author.

SNYDER: Yeah, sure, this is all fair game.

PVZ: Going back to the headlines your study generated, among those that I found curious was the Stanford headline publicizing your research. It said, “Massive biomolecular shifts occur in our 40s and 60s, Stanford Medicine researchers find.” That's a great headline that might inspire donors — and I know you didn't write the headline — but isn't characterizing this as applicable to all people a little misleading?

SNYDER: Yeah. It's a little strong. There's no question there are significant changes during those times, but whether "massive" is an overstatement — I don't know. I will say that the results are statistically significant. We're not cherry picking there.

PVZ: When I read the study, it issued caveats and qualified your findings accurately.

SNYDER: We try to be honest, too. We're scientists, after all.

PVZ: It seems like everybody from USA Today to Fox News to The Guardian and the Stanford marketing team took the ball a little bit further down the field than the science warranted.

SNYDER: They probably did, a little bit. On the other hand. I do think these are significant changes, and I do think it is worth people having a heads up.

Takeaways up front:

∞ certain human organs, each of which ages at a unique rate, are associated with either greater longevity or mortality risk, depending on the organs’ biological ages, according to a Stanford research paper

∞ of 11 organs tracked in more than 44,000 people over several years, the brain and immune system, together, uniquely correlated to disease-free human longevity

∞ except for the brain and immune system, having 5 to 7 other biologically “younger” organs actually correlated to an increased risk of mortality; and having 8 or more “extremely aged” organs increased the chances of dying early by what scientists often refer to as a shit ton

∞ of 137 drugs and supplements examined in the research, only six (see below) were “significantly associated” with having at least two youthful organs, which conferred slightly greater than average longevity

“A youthful brain and immune system are key to longevity”

In a convincing and slightly fascinating1 research paper, a group of Stanford University scientists studied the biological ages of 11 organs, over many years, from 44,526 people aged 40 to 69 whose blood and other sample tissue is stored in the U.K. Biobank2. What they learned is, to anyone in the latter half of life, worth understanding.

In this post, I reveal a couple hidden gems from that paper that I haven’t seen in any other published review of it.

But first, the paper’s noteworthy main finding:

“Surprisingly, brain aging was most strongly predictive of mortality,” the researchers wrote in their paper, which was published in June (but has yet to be peer reviewed), “suggesting that the brain may be a central regulator of lifespan in humans.” In fact, the study authors added, people with aged brains showed increased risk for several diseases beyond dementia, including serious lung disease and heart failure, “consistent with previous studies showing that the brain regulates systemic inflammation.^”

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To track how each of these 11 organs (brain, heart, kidney, liver, lung, pancreas, immune system, arteries, intestines, muscle and adipose tissue aka fat) aged over many years, the researchers tracked proteins produced by each organ.

To get a broader picture of what the research examined, I urge you to read this Washington Post article, by my former NYT colleague Gretchen Reynolds.

On to the two hidden gems in the paper’s findings that, to my surprise, haven’t been noted elsewhere:

1. Though biologically younger organs are better than having what the researchers called “extremely aged” organs, it turns out that having several younger-than-average organs actually correlated to a slightly greater than average mortality risk.

2. Of the 137 drugs or supplements the researchers tracked in the Biobank’s longitudinal data, only 6 — Premarin (a brand-name estrogen medicine), ibuprofen, glucosamine, cod liver oil, multivitamins and vitamin C — were significantly associated with having two or more youthful organs. Which, in turn, correlated to having slightly greater than average longevity.

Let’s look at each of these findings in greater detail.

1 | Two graphics that correlate organ age and mortality risk

In their paper, the Stanford researchers include two charts that visually summarize how biological organ age is associated with human mortality and longevity.

The chart below shows the impact on mortality risk of each “extremely aged” organ as well as the impact of extremely youthful organs. You can see that the combination of an extremely youthful brain and immune system, for example, has by far the strongest correlation to increased longevity; conversely, people with eight or more extremely old organs were at the highest risk for dying earlier than normal. (To understand how much mortality risk increases for each really old organ or combination of old organs, read this footnote.3)

But then notice the counterintuitive results:

As the researchers4 wrote, “We found individuals with youthful appearing arteries had increased mortality risk, and those with multi-organ youth had no difference in mortality risk compared to normal agers.” (Italics are mine.)

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“Multi-organ youth” doesn’t help you live longer?

It may not. According to the data, having a lot of extremely youthful organs is a greater mortality risk than having a couple very youthful organs.

The possible reasons for that are not covered in this paper. Apparently, it’s complicated. But if you trust AI to give you some reasonably sound food for thought, here are some possible explanations.

I’d rather be the blue line than the black. Yes I would.

Now, take a look at the graphic below, Fig. 4e from the study, which shows that “the accrual of aged organs progressively increases mortality risk,” the researchers write, “while a youthful brain and immune system are uniquely associated with disease-free longevity.”

By any measure, the blue line is the one to ride.

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2 | Five supplements and an estrogen med for younger organs

The correlation of younger organs to the use of Premarin, an estrogen medicine prescribed to women experiencing post-menopausal symptoms, is not surprising.

“Women with earlier menopause were age accelerated across nearly all organs, in line with the well-documented adverse health consequences of early menopause,” the research paper noted. “Conversely, estrogen treatment was associated with more youthful immune systems, livers, and arteries suggesting intervention with estrogen treatment may protect these organs from menopause-induced age acceleration resulting in extended survival.” Here’s the paper’s full passage on this subject.5

Ibuprofen, glucosamine, cod liver oil, multivitamins, and vitamin C “were associated with youth primarily in the kidneys, brain, and pancreas,” the paper said, without elaborating further. Perhaps the anti-inflammatory properties in ibuprofen and glucosamine help reduce chronic inflammation associated with organ aging; likewise, maybe the antioxidant properties in vitamin C and omega-3 fatty acids in cod liver oil help protect cells from oxidative stress, another big factor in the biology of aging.

I guess I’d rather eat a salmon than a steak. Yes I would.

Inside Longevity™ explores the news, data, people, companies and investors populating the longevity and anti-aging industries, and their interconnections.

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I’ve noticed that a lot of the online advice about intermittent fasting and its cousin, caloric restriction, is based on research on non-human organisms — mice, worms or yeast — or small groups of humans that the researchers invariably describe as “young and healthy.”

But what if you’re old and healthy? Or just older and deeply invested in staying as physically, mentally and physiologically strong as possible into your 50s, 60s and beyond? Is intermittent fasting, or caloric restriction, a practice you should embrace?

Some experts aren’t convinced intermittent fasting, or IF for short, does anything except help you drop a few pounds. I disagree with them, based on my and others’ experience, and in a brief audio follow-up to this post, I explain my reasons.

So, to the question about whether to embrace specifically IF, I think the answer for most healthy adults is a big, fat (pun intended), slightly qualified1 Yes. Here’s why.

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Intermittent fasting (IF) vs. caloric restriction (CR)

Intermittent fasting is the practice of limiting eating to within a specific daily range — say, 6 to 12 hours. Caloric restriction, by contrast, refers to reducing the overall amount of food you eat each day to a minimum, without limiting essential nutrients.

IF and CR each seem to emulate how humans have been wired to eat from the beginning: only when and if food became available.

Benefits and risks of CR

CR is more difficult to maintain over time and sort of rides the edge of human tolerances about what is, for many people, considered healthy. It’s not for dilettantes or most athletes (who need sufficient daily protein to avoid cannibalizing muscle tissue). CR is an advanced technique for people in good health who know their body’s needs very well2.

But if you’re able and healthy — and even if you’re 45, 50 or 70 — several more recently studies have shown even modest levels of CR (12-15% reductions in daily food consumption) can lead to powerful health and longevity benefits, including:

• improved muscle strength even as it reduces muscle mass

• aging slower (though not necessarily reducing biological age)

• an increase in cellular housekeeping and repair functions (known as autophagy) that keep the bits of our cells, called organelles, functioning

• a reduction in oxidative stress that increases with, and causes us to, age

• lowered blood sugar, cholesterol and inflammation

But CR done wrong can lead to health problems, including an overkill of autophagy that can have harmful effects at a cellular level. For most of us, a more achievable, less onerous alternative with many similar effects on reducing the rate of aging is intermittent fasting.

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A note about my experiences with CR and IF: For a long time, before I knew there was a term for it, I practiced a casual form of daily CR — eating just enough to avoid feeling irritably hungry — on the theory that it just might, as early studies suggested, slow down my biological aging process. CR certainly made me leaner (and sometimes meaner, unfortunately, due to being “hangry”) with steady, durable levels of energy; I never felt midday fatigue or a need for an afternoon coffee. I was eventually persuaded by a coach to stop CR and start eating more, and more often, because I was most likely damaging my athletic performance and my ability to keep, much less build, lean muscle.

I’m now an IF devotee, not eating after 6:30pm and usually not before 10am, unless I’m hungry, in which case I listen to my body. I find IF, which takes a while (weeks, if not months) to fully acclimate to, very effective at staying lean, strong, durably energetic and sharp and, I hope, aging slower than my actual years.

Benefits of intermittent fasting

If you can manage to not eat for even 12 hours (say, 7pm to 7am), you can succeed at IF. (In my non-expert experience, a daily eating window smaller than about 6 hours starts to feel like hardcore CR, especially if you’re exercising regularly.) Once you work your way up to 14 or 16 hours of fasting, eating only between mid-morning and mid-evening, your body begins burning stored fat and glucose for energy — yay! You may well lose a few pounds of flab, and then you’re on the glide path to many of the same benefits CR provides, including:

• improved brain health that, in research on animals, led to…

• a reduced risk of Alzheimer’s disease, Parkinson’s disease and stroke

• a reduced risk, according to research on animals, of cancer (perhaps the result of losing weight and lowering blood sugar and inflammation)

For women over 50, in particular, IF can have specific benefits that include weight loss and mitigating the effects of menopause. But show me a 50-year-old guy who isn’t also interested in having IF’s cellular-level housecleaning function slow down his aging process, and I’ll show you Wilford Brimley.

Practitioners in praise of IF

Moran Hermesh, a functional medicine dietician based in Santa Monica, Calif., practices IF herself and recommends the practice to her clients — regardless of gender. “It creates a lot of health benefits,” she told me in an interview for this article. “It really cuts out those extra calories after dinner that contributes to weight gain and inflammation.”

Can you practice IF and still exercise regularly, train hard, build muscle and operate and peak physical, mental and physiological levels? Definitively, yes, you can — if you eat the right foods and nutrients. To succeed at IF, eating consistently is crucial, Hermesh said. “In this 8-hour window, you do need to eat every two to three hours, 25 to 30 grams of protein.”

This is a process of learn-and-adapt that requires time to figure out. Hermesh says she teaches her clients to “only eat what your body needs” and “to be never hungry and never full.”

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This post follows up the article I published last month about a study that showed how a small group of women 46 to 65 lowered their biological ages by an average of almost 5 years by following a strict but achievable daily nutrition, exercise and stress-mitigating regimen.

I subsequently interviewed Dr. Kara Fitzgerald, the lead author of that 2023 study, and asked her about:

• The reasons for including liver in participants’ weekly diet (as a whole food or supplement)

• Why she kept the daily diet free of beans/legumes and dairy

• Her book, “Younger You,” which includes the full daily regimen that her two aging-related studies indicate may consistently lower biological age

• The negative impact of stress on biological age

Our conversation also touched on epinutrients, which help turn on processes that benefit our health and lifespans, and briefly on DNA methylation, a biological process that affects how our genes are expressed and, as a result, how we biologically age. More about those in a future post.

But first, liver! Why liver?

Dr. Fitzgerald’s study had participants eating three 3-ounce servings of organic liver a week, either as a whole food or as a supplement, because it packs the biggest punch.

“Liver is the most nutritionally dense food out there,” she told me. “It contains folate, B-12, cholene — those epinutrients that fall in the methyl category.”

If you’re not up for eating liver, she recommends liver supplements, which she said she takes as part of her weekly diet.

The reasons against including beans and dairy in her study

Dr. Fitzgerald avoided including beans in her nutrient plan for study participants, she said, because of it’s propensity to raise blood sugar and cause digestive issues. Dairy is also a “pretty common inflammatory food for a lot of individuals,” she said.

Her 2023 study of middle-aged women was designed, she said, to be broadly tolerable and anti-inflammatory for the study period.

Her book: “Younger You”

Published in 2022, Dr. Fitzgerald’s book includes the specific biological-age-reducing diet in her 2023 study. The book includes a 30-page epinutrient appendix.

The book is a followup to Dr. Fitzgerald's novel 2021 study of 43 healthy men aged 50-72 which, she said, was the first randomized, controlled trial to show biological age reversal through diet and lifestyle changes.

“That 2021 paper was the first of its kind in the world,” she said, and when she formulated the study, in 2019, biological age reversal in humans was not yet an established concept.

Stress reduction as a vital component of lowering biological age

Her 2021 and 2023 studies on how to reduce biological age required participants to do daily breathing exercises that most of those people struggled to complete. The average compliance rate was less than 60%. And yet, according to Dr. Fitzgerald, the exercises, which are meant to reduce the impact of daily stress on one’s aging process, can have a large impact.

“In the literature, it really does seem that stress is a huge factor in aging,” she told me.

A biological age blood test?

Dr. Fitzgerald's website offers a testing package using TruDiagnostic's DunedinPACE of Aging test. (The tests appear to be out of stock as of this writing, fyi.) I haven’t done the test so can’t offer an opinion on it. But the idea is to test your biological age before and after embarking on a daily nutrition, exercise and meditation/breathing regimen for two months or longer.

I’ll write about epinutrients, and their role in biological aging, in a future article.

Inside Longevity™ explores the news, data, people, companies and investors populating the longevity and anti-aging industries, and their interconnections.

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I recently came across a study in the journal Aging that showed how a strict but achievable two-month dietary and lifestyle regimen lowered the biological ages of its participants by an average of 4.6 years. Other studies have shown similar findings, but what made this study different is that its subjects were all healthy women 46 to 65 years old.

Also notable is that the study’s dietary requirements to reverse biological aging were not draconian, not vegan and not even vegetarian. More on the specifics below.

What is biological age and why does it matter?

Biological age refers to how old your cells are and can differ significantly from your chronological age, which is simply how many years you’ve lived. Having a lower biological age means your body is aging slower than someone of your chronological age. You’ll often hear this referred to as “reversing the aging process,” because many studies have shown how diet and lifestyle changes over the course of several weeks can reverse your aging clock by several years. A lower biological age has a huge positive impact on your ability to avoid chronic physical and cognitive disease1, some form of which now afflicts a majority of American adults.

You don’t need to be vegan, vegetarian or a biohacker to slow aging

That’s why this 2023 study, led by Dr. Kara Fitzgerald (read about my subsequent interview with her in this follow-up post), struck me as a longevity treasure map for women and men who want the undeniable benefits of maintaining a younger biological self but who also want to live and eat like a relatively normal human, and not like a self-obsessed biohacker with $1,000 worth of supplements in the cupboard and an 18-year-old blood boy on speed dial.

To the contrary, the daily regimen that Dr. Fitzgerald’s study required its participants to complete seemed achievable by many everyday people, in terms of required time and expense — though it does mean eating a lot of certain kinds of vegetables, eating liver (or liver supplement) and taking two other supplements and exercising daily.

The daily regimen that reversed biological age in 2 months

(See the full program below). Each day, you’ll need to eat lots and lots of dark leafy greens (sadly, the Spring Mix I usually buy doesn’t count).

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