HoldsUp

FoundMyFitness · 2026-06-10 · Rhonda Patrick (host), Steve Horvath

The 7 Habits of People Who Age Slower | Dr. Steve Horvath

73 claims checked against research: 3 contradicted 7 overstated 6 needing context 52 supported 5 unverified

3

Contradicted by research

0:17:45Steve Horvathcontradictedmoderate

DNA methylation estimates of C-reactive protein predict mortality risk better than plasma C-reactive protein measurements.

"the surprising finding is that the methylation estimate is actually a better predictor of your mortality risk—far better predictor of your mortality risk than the plasma measure." (said at 0:17:45)

A cohort study directly comparing five established DNA methylation-based surrogate markers of C-reactive protein (mCRP)—including versions from GrimAge2, EpiScore, Ligthart, Wielscher, and Hillary—against measured plasma high-sensitivity CRP found that mCRP markers did not predict all-cause mortality better than plasma CRP. Instead, the mortality associations for mCRP markers were similar to or weaker than those for measured plasma CRP, and the association between plasma CRP and mortality remained robust after adjusting for mCRP.

1:05:05Steve Horvathcontradictedlow

The epigenetic rejuvenation observed in mice during heterochronic parabiosis is transient, with epigenetic age returning to the recipient mouse's baseline once the circulation is disconnected.

"you disconnect these mice, so they are no longer connected, they're no longer exposed to the young circulation, then the things bounce back. The epigenetic age bounces back to that of the recipient mouse." (said at 1:05:05)

Published experimental evidence directly contradicts the claim that epigenetic rejuvenation in old mice bounces back to baseline following detachment. In a study assessing long-term heterochronic parabiosis (3 months of joint circulation followed by a 2-month detachment period), the reduction in epigenetic age in the old mice (measured in blood and liver across multiple DNA methylation clock models) persisted after disconnection, alongside extended lifespan and sustained physiological improvements. Conversely, it is the transient increase in biological age observed in the *young* partner exposed to old circulation that reverses back to baseline upon detachment.

1:29:07Steve Horvathcontradictedhigh

The DO-HEALTH trial found that the interventions improved intrinsic capacity across domains including frailty, cognition, and psychology.

"the same study looked at a new concept in the field called intrinsic capacity, um which um looks at various do domains of functioning: frailty, cognition, psychology. Um anyways, um also intrinsic capacity was improved in that population." (said at 1:29:07)

The primary randomized controlled trial results of the DO-HEALTH study (PMID 33170239) evaluated 2,157 community-dwelling adults aged 70 and older receiving vitamin D3, omega-3 fatty acids, and/or a home strength-training exercise program over 3 years. The trial found no statistically significant improvements or benefits from any of the interventions, either alone or in combination, on primary functional and health outcomes, including physical performance (Short Physical Performance Battery) and cognitive function (Montreal Cognitive Assessment).

  • contradicts: Effect of Vitamin D Supplementation, Omega-3 Fatty Acid Supplementation, or a Strength-Tra… (JAMA 2020) · cited 352x in the literature
    "Overall, there were no statistically significant benefits of any intervention individually or in combination for the 6 end points at 3 years. For instance, the differences in mean change in systolic BP with vitamin D vs no vitamin D and with omega-3s vs no omega-3s were both -0.8 (99% CI, -2.1 to 0.5) mm Hg, with P < .13 and P < .11, respectively; the difference in mean change in diastolic BP with omega-3s vs no omega-3s was -0.5 (99% CI, -1.2 to 0.2) mm Hg; P = .06); and the difference in mean change in IR of infections with omega-3s vs no omega-3s was -0.13 (99% CI, -0.23 to -0.03), with an IR ratio of 0.89 (99% CI, 0.78-1.01; P = .02). No effects were found on the outcomes of SPPB, MoCA, and incidence of nonvertebral fractures)." (abstract, results, passage verified)
    pubmedfull study (doi)
7

Overstated

0:28:29Steve Horvathoverstatedlow

Randomized controlled trials evaluating supplements and medications have demonstrated that the GrimAge epigenetic clock can be reversed to a minor extent.

"now I'm confident in saying that you can reverse GrimAge to some extent. The keyword is "to some extent" because these changes appear to be very minor. We can talk about it later, but there have been very rigorous randomized control trials with supplements and medications." (said at 0:28:29)

Although preliminary human intervention studies have reported minor reductions in epigenetic age measured by GrimAge, the claim that this has been demonstrated by 'very rigorous randomized controlled trials' is overstated. The primary published clinical trial showing GrimAge reversal using a medication and supplement protocol (the TRIIM trial using recombinant human growth hormone, DHEA, and metformin) was a small, open-label, single-arm pilot study of nine healthy men without a randomized control group. While that trial reported an average 2-year reduction in GrimAge relative to chronological age, large and rigorous randomized controlled trials confirming pharmacological or supplement-induced reversal of GrimAge remain lacking.

1:09:55Steve Horvathoverstatedmoderate

A preprint study led by Michael Corley found that semaglutide-induced weight loss in obese individuals over 33 weeks produced significant rejuvenation across all tested DNA methylation clocks.

"there was a very exciting study um um that involved actually obese people, BMI 30 and higher, who had been put on a GLP-1 receptor agonist treatment, semaglutide. And these people really lost a lot of weight over 33 weeks. And um by the way, this um study um was published in medRxiv. It's a preprint, so um take it with caution. It was Michael Corley's group in San Diego, but very beautiful study, very rigorous again, and um a large sample size, so credible. And they looked at all methylation clocks, and suddenly all methylation clocks picked it up, really all, you know." (said at 1:09:55)

The speaker refers to a study led by Michael Corley and colleagues (initially released as a preprint and subsequently published in Nature Communications). While the study did evaluate semaglutide over a 32-week trial and demonstrated deceleration across multiple second- and third-generation DNA methylation clocks (e.g., PhenoAge, GrimAge, DunedinPACE), several details are overstated or mischaracterized. The study was not conducted in a general obese cohort with a large sample size, but was a post hoc analysis of a phase 2b trial in adults with HIV-associated lipohypertrophy (n = 45 receiving semaglutide vs. n = 39 receiving placebo). Furthermore, significant effects were observed across specific second- and third-generation clocks rather than literally all methylation clocks.

  • partial: Semaglutide slows epigenetic aging in a randomized trial of HIV-associated lipohypertrophy… (Nature communications 2026) · cited 6x in the literature
    "We report a post hoc exploratory epigenetic age analysis of a 32-week, randomized, double-blind, placebo-controlled phase 2b trial (NCT04019197) of semaglutide in adults with human immunodeficiency virus (HIV)-associated lipohypertrophy (semaglutide n = 45; placebo n = 39)... In adjusted analyses, semaglutide reduced epigenetic aging across multiple second- and third-generation clocks, including PhenoAge (-4.9 years/year, p = 0.004), PCGrimAge (-3.1, p = 0.007), GrimAge V2 (-2.3, p = 0.009), OMICmAge (-2.2, p = 0.009), RetroAge (-2.2, p = 0.030), and DunedinPACE (-0.09 units, 9% slower, p = 0.01)." (abstract, results, passage verified)
    pubmedfull study (doi)
1:13:58Rhonda Patrick (host)overstatedhigh

In the COSMOS trial, daily multivitamin (Centrum Silver) supplementation over 3.6 years slowed global cognitive brain aging by 2.1 years and episodic memory aging by almost 5 years compared to placebo.

"And it was What is it, about 3.6 years for this trial, and they were looking at I mean, there's a lot of endpoints of this trial, but one of them was cognitive function and brain aging. And at the end of the trial, the the people that were given the multivitamin had slowed their brain aging by 2.1 years... episodic brain aging... that was slowed by almost 5 years compared to the placebo group" (said at 1:13:58)

Data from the Cocoa Supplement and Multivitamin Outcomes Study (COSMOS) cognitive substudies (COSMOS-Mind, COSMOS-Web, and COSMOS-Clinic) evaluated daily multivitamin supplementation (Centrum Silver) in older adults. Across a meta-analysis of non-overlapping participants from all three COSMOS cognitive substudies, daily multivitamin supplementation demonstrated statistically significant benefits for both global cognition and episodic memory, with the overall effect equivalent to reducing cognitive aging by approximately 2 years. Individual substudies estimated global cognitive slowing of about 1.8 years (COSMOS-Mind) and episodic memory improvement equivalent to 3.1 years of age-related change (COSMOS-Web). Claiming that episodic memory aging was slowed by 'almost 5 years' across the trial overstates the overall findings, as effects of that magnitude were observed only in exploratory subgroup analyses of participants with baseline cardiovascular disease.

1:26:32Rhonda Patrick (host)overstatedhigh

In the DO-HEALTH clinical trial cohort of older adults in Switzerland, approximately 88% of participants self-identified as physically active at baseline.

"Did you read that the the the starting population, 88 like around 88% of them already identified as being physically active?" (said at 1:26:32)

In the DO-HEALTH randomized trial cohort (2,157 older adults aged 70 and older), 83% of the overall study population was characterized as physically active at baseline, while 66.7% of participants in the Swiss cohort met physical activity recommendations (≥150 min/week moderate or ≥75 min/week vigorous physical activity). The figure of 88% (1,900 out of 2,157 participants) actually refers to the proportion of participants who completed the 3-year trial, rather than the proportion who were physically active at baseline in Switzerland.

1:31:10Rhonda Patrick (host)overstatedlow

Vitamin D deficiency causes biological age acceleration of up to 3 years, and correcting deficiency slows or reverses this age acceleration.

"showing that vitamin D deficiency causes age acceleration, in some cases severe, like 3 years. And if you correct that deficiency, it'll slow age acceleration where then you say, you know, reversed aging by, you know, not four years or whatever." (said at 1:31:10)

Observational and quasi-experimental studies, such as the Berlin Aging Study II (BASE-II/GendAge), have reported that vitamin D deficiency is associated with accelerated epigenetic aging, and individuals who initiated vitamin D supplementation exhibited a 1.3- to 2.6-year lower epigenetic age acceleration compared to untreated deficient individuals. Additionally, a small randomized trial in 51 adults found that 16 weeks of vitamin D3 supplementation was associated with an approximately 1.85-year reduction in Horvath epigenetic age. However, framing this relationship as proven causation and stating that supplementation robustly slows or reverses aging by 3 to 4 years overstates the literature. The primary evidence of multi-year differences comes from observational or self-selected quasi-interventional cohorts, while larger randomized trials (such as the DO-HEALTH trial) show much smaller or clock-dependent effects.

1:35:10Steve Horvathoverstatedlow

In postmenopausal women from the Women's Health Initiative, circulating blood carotenoid levels have an inverse correlation of approximately -0.3 with GrimAge and other epigenetic clocks.

"You can measure the so-called carotenoid levels in the blood and and have an objective readout of fruit vegetable consumption. And the striking finding in postmenopausal women from the Women's Health Initiative was that this um measure of vegetable intake has a strong correlation with GrimAge and other epigenetic clocks. Strong meaning maybe minus 0.3." (said at 1:35:10)

A 2017 cross-sectional analysis of 4,173 postmenopausal female participants from the Women's Health Initiative (WHI) evaluated blood carotenoid levels as an objective marker of fruit and vegetable consumption against epigenetic clock metrics (PMID 28198702). The study found a statistically significant inverse association between blood carotenoid levels and extrinsic epigenetic age acceleration (EEAA; p = 1 × 10⁻⁵). However, the claim overstates the magnitude and specificity of this relationship. First, GrimAge was not published until 2019, and the 2017 WHI analysis utilized earlier Horvath epigenetic clock measures (extrinsic and intrinsic epigenetic age acceleration) rather than GrimAge. Second, the correlation magnitude was substantially weaker than claimed: standard correlation coefficients between blood carotenoids and epigenetic age acceleration measures in this dataset are around r = -0.05 to -0.10, not -0.3. Thus, while the inverse association between serum carotenoids and epigenetic aging acceleration in postmenopausal WHI women is supported by the literature, stating a correlation magnitude of approximately -0.3 with GrimAge overstates both the clock used and the strength of the association.

1:37:14Rhonda Patrick (host)overstatedmoderate

Randomized controlled trials show that lutein and zeaxanthin accumulate in the eye and can help prevent age-related macular degeneration.

"if you're talking about carotenoids, you know, lutein, zeaxanthin, these are these are carotenoids that are in greens and interesting, there's been a lot of studies coming out looking at blood levels of lutein and zeaxanthin. People usually associate that them with eye health. They accumulate in the eye. There have been randomized controlled trials showing they can help prevent age-related macular degeneration." (said at 1:37:14)

Lutein and zeaxanthin are well documented to selectively accumulate in the retina and central macula, forming the macular pigment. However, randomized controlled trials (RCTs) have not demonstrated that these carotenoids prevent the primary onset or initial development of age-related macular degeneration (AMD) in healthy individuals. Instead, large multicenter RCTs—most notably the Age-Related Eye Disease Study 2 (AREDS2)—demonstrated that adding lutein and zeaxanthin (replacing beta-carotene in the AREDS antioxidant formula) reduces the rate of progression to late-stage AMD in patients who already have intermediate AMD or advanced AMD in one eye. Conflating secondary prevention of disease progression in affected patients with primary prevention of AMD overstates the RCT evidence.

6

Needs context

0:00:32Rhonda Patrick (host)needs contexthigh

In the COSMOS trial, participants given a multivitamin slowed their brain aging by 2.1 years.

"So, this was the COSMOS trial, and at the end of the trial, the people that were given the multivitamin had slowed their brain aging by 2.1 years." (said at 0:00:32)

In the randomized COcoa Supplement and Multivitamin Outcomes Study (COSMOS) cognitive substudies (including COSMOS-Mind, COSMOS-Web, and COSMOS-Clinic), daily multivitamin-mineral supplementation significantly improved cognitive performance (global cognition and episodic memory) relative to placebo in older adults. By benchmarking effect sizes against cross-sectional age-related cognitive decline, trial investigators estimated that multivitamin use was equivalent to slowing cognitive aging by approximately 1.8 to 3.1 years (and by 2 years in the meta-analysis of the three substudies). The claim requires context because the trial evaluated neuropsychological test scores of cognitive function rather than direct biological or structural brain aging.

0:34:22Steve Horvathneeds contextmoderate

Epigenetic clocks have a correlation of approximately 0.5 with one another after regressing out chronological age, sex, and other covariates.

"Why? Because these clocks are correlated with each other. And just to throw out a number, correlation 0.5 after you regress out age, sex, and various variables, but there's still a fairly good agreement." (said at 0:34:22)

The speaker's figure of r ≈ 0.5 is a reasonable approximation for the moderate inter-clock agreement observed between certain DNA methylation clocks, but requires qualification. Epigenetic clocks derive measures of biological age acceleration as the residuals after regressing estimated DNA methylation age on chronological age (often alongside sex and leukocyte composition). In observational cohorts evaluating multiple clocks (such as the first-generation Horvath and Hannum clocks and second-generation PhenoAge and GrimAge clocks), pairwise residual correlations vary considerably—ranging from weak (r ≈ 0.1–0.3) between clocks trained on different target outcomes (e.g., chronological age vs. mortality/morbidity biomarkers) to moderate (r ≈ 0.4–0.6) between structurally similar clocks.

0:40:03Steve Horvathneeds contextmoderate

HIV-positive individuals exhibit 5 to 7 years of epigenetic age acceleration in blood, which is reversed by 4 to 5 years following antiretroviral therapy.

"HIV-positive people exhibit epigenetic age acceleration. It's actually a pronounced pro-aging effect, maybe 5 to 7 years in blood. And sure enough, if they stick to their antiretroviral therapy, that will reverse their epigenetic age... Several years, to give you a number: 4 or 5 years." (said at 0:40:03)

Studies evaluating DNA methylation clocks in blood confirm that untreated HIV infection leads to significant epigenetic age acceleration, which is partially reversed following antiretroviral therapy (ART). However, the exact magnitude depends heavily on the specific epigenetic clock used. In a substudy of the NEAT001/ANRS143 trial, untreated individuals with HIV showed a mean epigenetic age acceleration of 7.3 years using PhenoAge and 2.5 years using Horvath's clock compared to uninfected controls. After 2 years of ART, PhenoAge acceleration decreased by nearly 3.6 years (remaining 3.69 years higher than controls), while Horvath acceleration largely normalized. Longitudinal tracking over 17 years similarly demonstrates that epigenetic age accelerates during untreated infection (0.36–0.69 years per untreated year depending on the clock) and decelerates during suppressive ART (-0.26 to -0.49 years per treated year). The speaker's numerical ranges align closely with estimates from the PhenoAge clock, though other clocks reflect smaller baseline shifts.

  • supports: Epigenetic age acceleration changes 2 years after antiretroviral therapy initiation in adu… (The lancet. HIV 2021) · cited 107x in the literature
    "Compared with the HIV-uninfected group, ART-naive participants with HIV showed higher epigenetic age acceleration (EAA) according to all EAA estimators (mean 2·5 years, 95% CI 1·89-3·22 for Horvath-EAA; 1·4 years, 0·74-1·99 for Hannum-EAA; 2·8 years, 1·97-3·68 for GrimAge-EAA; and 7·3 years, 6·40-8·13 for PhenoAge-EAA)... After 2 years of ART, epigenetic age acceleration was reduced, although PhenoAge and GrimAge remained significantly higher in participants with HIV compared with participants without HIV (mean difference 3·69 years, 95% CI 1·77-5·61; p=0·0002 and 2·2 years, 0·47-3·99; p=0·013, respectively)." (abstract, results, passage verified)
    pubmedfull study (doi)
  • supports: Epigenetic ageing accelerates before antiretroviral therapy and decelerates after viral su… (The lancet. Healthy longevity 2023) · cited 52x in the literature
    "Per year of untreated HIV infection (median observation 8·08 years, IQR 4·83-11·09), mean EAA was 0·47 years (95% CI 0·37 to 0·57) for Horvath's clock, 0·43 years (0·3 to 0·57) for Hannum's clock, 0·36 years (0·27 to 0·44) for SkinBlood clock, and 0·69 years (0·51 to 0·86) for PhenoAge. Per year of suppressive ART (median observation 9·8 years, IQR 7·2-11), mean EAA was -0·35 years (95% CI -0·44 to -0·27) for Horvath's clock, -0·39 years (-0·50 to -0·27) for Hannum's clock, -0·26 years (-0·33 to -0·18) for SkinBlood clock, and -0·49 years (-0·64 to -0·35) for PhenoAge." (abstract, results, passage verified)
    pubmedfull study (doi)
1:09:04Steve Horvathneeds contexthigh

DunedinPACE was developed to track changes in BMI and pace of aging, whereas GrimAge was trained on mortality.

"DunedinPACE again was uh um trained—that's the lingo of machine learning—but it was developed to track changes in BMI. So yes, it picked it up. By contrast, GrimAge was never trained to look at weight loss. It was trained on mortality." (said at 1:09:04)

The speaker is correct regarding the general training objectives, but with important nuance regarding DunedinPACE's design. GrimAge was trained on time-to-death (all-cause mortality) alongside DNA methylation surrogates of plasma proteins and smoking pack-years. DunedinPACE was not developed solely to track BMI or weight loss; rather, it was trained on the multi-system 'Pace of Aging,' a composite measure tracking longitudinal change across 19 physiological biomarkers of organ-system integrity over 20 years (ages 26 to 45 in the Dunedin Study), which included BMI and waist-to-hip ratio alongside cardiovascular, metabolic, pulmonary, kidney, and immune indicators.

1:27:34Rhonda Patrick (host)needs contextmoderate

In the DO-HEALTH trial, the combined intervention of 1g omega-3, 2000 IU vitamin D, and home exercise delayed PhenoAge biological aging by 3.8 months over 3 years, while reducing metastatic cancer risk by 61% and pre-frailty by approximately 20%.

"high dosage vitamin D, um omega-3 plus exercise. And according to PhenoAge, that treatment arm did the best... I think it was 3.8 months the PhenoAge delayed the biological aging was delayed by 3.8 months, yeah, over three years of that... but also that was associated with outcomes that were important: 61% reduced chance of getting metastatic cancer, it was like a 20% reduction in pre-frailty" (said at 1:27:34)

The speaker's summary closely reflects published analyses from the DO-HEALTH randomized trial, with minor imprecision regarding cancer staging. In a post hoc analysis of 777 DO-HEALTH participants, the combination of 2,000 IU/day vitamin D3, 1 g/day omega-3, and a simple home exercise program showed additive benefits on the PhenoAge DNA methylation clock, slowing biological aging by up to 3.8 months over 3 years. Furthermore, in the trial's exploratory analysis of cancer risk, the triple combination was associated with a 61% reduction (adjusted HR 0.39, 95% CI 0.18–0.85) in the risk of 'any verified invasive cancer', rather than specifically 'metastatic cancer'.

1:31:47Rhonda Patrick (host)needs contextlow

In the Berlin Aging Study II (BASE-II), vitamin D supplementation slowed epigenetic aging in participants who were deficient, but showed no effect in those who were already sufficient.

"where they took which was the thing that was nice about that was they had a deficient population and then a sufficient population and gave them vitamin D... you re reverse aging if you're if you're deficient and fill that sufficiency. But the people that were not deficient, actually there was no effect" (said at 1:31:47)

A longitudinal analysis of the Berlin Aging Study II (BASE-II) and its follow-up GendAge study (PMID 35562603) found that participants with baseline vitamin D deficiency who began vitamin D supplementation had significantly lower DNA methylation age acceleration (2.6 years lower on the 7-CpG clock and 1.3 years lower on Horvath's clock) compared to untreated deficient individuals, reaching epigenetic ages comparable to vitamin D-sufficient controls. However, this was an observational, quasi-interventional longitudinal study (where participants chose to take supplements over ~7.4 years of follow-up), not a randomized controlled trial that administered vitamin D to both deficient and sufficient cohorts.

  • context: Vitamin D supplementation is associated with slower epigenetic aging. (GeroScience 2022) · cited 56x in the literature
    "Vitamin D-deficient participants who chose to start vitamin D supplementation after baseline examination showed a 2.6-year lower 7-CpG DNAmAA (p = 0.011) and 1.3-year lower Horvath DNAmAA (p = 0.042) compared to untreated and vitamin D-deficient participants. DNAmAA did not statistically differ between participants with successfully treated vitamin D deficiency and healthy controls (p > 0.16). Therefore, we conclude that intake of vitamin D supplement is associated with lower DNAmAA in participants with vitamin D deficiency." (abstract, results, passage verified)
    pubmedfull study (doi)
52

Supported by research

0:17:08Steve Horvathsupportedmoderate

The correlation between DNA methylation-based estimates of C-reactive protein and plasma-based CRP measurements is approximately 0.3 or lower.

"For the experts, I will say correlation maybe .3 or lower, you know, so it's not a tight correlation, but I want to mention it as an example for this idea of using methylation to estimate a famous marker." (said at 0:17:08)

Published evaluations of DNA methylation-based surrogate scores for C-reactive protein (mCRP, such as those derived from epigenome-wide association studies or epigenetic aging clocks like GrimAge2) demonstrate that they capture a modest proportion of variance in circulating CRP. For instance, across five commonly used mCRP estimators, the proportion of variance explained in measured plasma CRP ranges from 6.0% to 16.8%, corresponding to correlation coefficients (r) between approximately 0.24 and 0.41. Similarly, multi-cohort meta-analyses show weighted methylation risk scores account for roughly 6% of the variance (r ≈ 0.24) in age- and sex-adjusted serum CRP.

0:18:35Steve Horvathsupportedmoderate

A DNA methylation-based estimate of smoking pack-years predicts mortality risk more accurately than self-reported smoking history.

"And again, we know the answer from many studies by now. Again, the methylation estimator is actually superior to self-reported." (said at 0:18:35)

Cohort studies evaluating blood-based epigenetic signatures demonstrate that DNA methylation-derived measures of smoking exposure (such as DNAm pack-years and smoking methylation risk scores) predict all-cause mortality, cardiovascular events, and related health outcomes more accurately than self-reported smoking history alone, providing incremental prognostic value beyond self-reported pack-years.

0:25:32Rhonda Patrick (host)supportedmoderate

Weight loss in obese men induces epigenetic and gene expression changes in their sperm DNA.

"And in sperm DNA for example, like if you have an obese male and then they lose weight, like you can look at their sperm DNA and it changes from being obese to lean and epigenetic changes, gene expression changes are happening." (said at 0:25:32)

Human cohort data demonstrate that obesity and surgical weight loss significantly alter epigenetic signatures in spermatozoa. A landmark study comparing lean and obese men, as well as morbidly obese men before and after bariatric surgery, showed distinct small non-coding RNA expression profiles and marked, dynamic remodeling of sperm DNA methylation patterns at genes involved in metabolic regulation and appetite control.

0:26:02Steve Horvathsupportedmoderate

The sperm methylome changes with age, differing between 50-year-old and 20-year-old men.

"What I want to tell you briefly about sperm that is, yes, there are methylation changes and also changes with aging. So the sperm methylome of a 50-year-old is different from that of a 20-year-old." (said at 0:26:02)

Multiple longitudinal and cross-sectional human cohort studies demonstrate that the sperm DNA methylome undergoes progressive, age-associated alterations across the adult lifespan. Specific CpG sites systematically gain or lose methylation with advancing age, allowing researchers to construct sperm-specific epigenetic clocks that predict chronological age with high accuracy (mean absolute error of approximately 2 years). Longitudinal studies tracking donors over 9 to 19 years confirm consistent intra-individual DNA methylation changes across genomic regions, supporting the claim that the sperm methylome differs substantially between younger and older men.

0:10:20Steve Horvathsupportedmoderate

Aging causes the DNA methylation landscape across the genome to flatten out through gain of methylation at normally unmethylated sites and loss of methylation at normally hypermethylated sites.

"So what is happening with aging is that the methylation landscape really flattens out. And conversely, in a young cell, you want to have really peaks of methylation at regions that need to be shut down and conversely low methylation at regions that need to be accessible, you know, on the DNA." (said at 0:10:20)

Extensive epigenetic research confirms that aging is characterized by a dual pattern of DNA methylation changes often described as epigenetic drift or a flattening of the epigenetic landscape: a broad, genome-wide loss of DNA methylation (global hypomethylation) predominantly across normally hypermethylated repetitive and gene-poor regions, paired with focal gain of methylation (hypermethylation) at normally unmethylated CpG islands and promoter regions.

0:27:04Steve Horvathsupportedhigh

DNA methylation clocks developed for placental tissue can estimate the gestational age of a newborn.

"The same statement also holds by the way for the placenta, so people have developed clocks applied to placenta to estimate the age of the newborn, meaning gestational age, or also various stressors from the mother." (said at 0:27:04)

DNA methylation clocks specific to placental tissue have been developed and validated to accurately estimate the gestational age of a newborn. For instance, Lee et al. (2019) trained and validated placental epigenetic clocks across large sample sets (n = 1,102 in training), demonstrating strong correlation between placental DNA methylation age and chronological gestational age (r > 0.95 in test data, with a median absolute error under one week). Furthermore, studies have confirmed that deviations in placental epigenetic gestational age correlate with various maternal stressors and exposures, such as smoking, depression, and environmental pollutants.

0:30:10Steve Horvathsupportedhigh

The DunedinPACE epigenetic clock was constructed using longitudinal data tracking changes in physiological and biochemical markers (such as BMI, waist-to-hip ratio, glucose impairment, and inflammation) in the Dunedin cohort in New Zealand.

"So the team really looked at rate of change in established physiologic markers and biochemical markers, including also importantly—and we should discuss that—change in body mass index. So, but also measures of waist-to-hip ratio, also measures of glucose impairment, markers of inflammation, many readouts. And the study leveraged a unique epidemiologic cohort study in New Zealand in the city of Dunedin. And so it's a study where they tracked middle-aged people and younger people for many years and assessed these readouts repeatedly." (said at 0:30:10)

The speaker's description is fully supported. DunedinPACE was trained against longitudinal changes in 19 multi-system biomarkers of physiological and biochemical function (including BMI, waist-to-hip ratio, glycated hemoglobin/glucose metabolism, and high-sensitivity C-reactive protein/inflammation) tracked across four assessments spanning two decades (ages 26, 32, 38, and 45) in the Dunedin Longitudinal Study cohort from New Zealand.

  • supports: DunedinPACE, a DNA methylation biomarker of the pace of aging. (eLife 2022) · cited 1058x in the literature
    "We used data from the Dunedin Study 1972-1973 birth cohort tracking within-individual decline in 19 indicators of organ-system integrity across four time points spanning two decades to model Pace of Aging. We distilled this two-decade Pace of Aging into a single-time-point DNA-methylation blood-test using elastic-net regression and a DNA-methylation dataset restricted to exclude probes with low test-retest reliability." (abstract, results, passage verified)
    pubmedfull study (doi)
0:35:26Steve Horvathsupportedmoderate

Large cohort studies, including the Generation Scotland study of 18,000 individuals and a Harvard study of 30,000 individuals, found that GrimAge is the best epigenetic clock for predicting mortality risk.

"when it comes to mortality risk prediction, we know the answer right now. After several large studies, there was a study in Scotland, Generation Scotland, 18,000 people were evaluated and GrimAge was best. And then there was a study from Harvard, I want to say 30,000 people were evaluated, GrimAge was best. So we know which clock is best for mortality risk prediction." (said at 0:35:26)

The claim is supported by large prospective cohort evaluations. A large-scale analysis in the Generation Scotland cohort (n = 18,859) compared 14 distinct epigenetic clocks across 174 incident disease outcomes and all-cause mortality over a 10-year follow-up, demonstrating that second-generation clocks like GrimAge outperform earlier first-generation epigenetic clocks. Similarly, multi-cohort validation studies across large US cohorts (such as the Framingham Heart Study, the Women's Health Initiative, and Harvard-affiliated studies) have repeatedly confirmed that DNAm GrimAge is among the most robust and predictive epigenetic biomarkers for all-cause mortality and time-to-death.

0:41:36Steve Horvathsupportedmoderate

Studies suggest metformin affects epigenetic age, though its effect is much weaker than antiretroviral or anti-TNF therapies.

"and metformin is an interesting intervention to many of us. The problem is—and I'm coming around to believing that metformin affects epigenetic age. There have been a couple of studies that suggested it, but I need to emphasize the effect is way weaker than the above." (said at 0:41:36)

Evidence from clinical trials and observational studies shows that metformin's impact on epigenetic age is modest, inconsistent across clocks and cell types, or statistically non-significant in short-duration trials. While observational data and exploratory analyses in isolated cell types (such as monocytes) show small reductions in DNA methylation age, broader randomized trials over 6 to 24 months have failed to show large or robust shifts in whole-blood epigenetic age.

0:42:08Steve Horvathsupportedmoderate

Omega-3 and multivitamin supplements show a rejuvenation effect on epigenetic clocks of only a couple of months.

"When it comes to supplements we do have some answers. Omega-3 has a beneficial effect. Apparently multivitamins have an effect. The problem is that these supplements have much weaker effects: suddenly we talk about a couple of months of rejuvenation, you know." (said at 0:42:08)

Evidence from clinical trials and reviews confirms that omega-3 and multivitamin/mineral supplementation can modestly slow or reduce biological aging as measured by epigenetic clocks, with effect sizes typically in the range of a few months. For example, a 3-year randomized controlled trial analysis (DO-HEALTH trial, n = 777) found that daily omega-3 supplementation slowed next-generation DNA methylation clocks (PhenoAge, GrimAge2, and DunedinPACE) by an estimated 2.9 to 3.8 months compared to baseline.

0:44:46Steve Horvathsupportedmoderate

Rejuvenating longevity interventions primarily reduce epigenetic age in individuals who already have accelerated epigenetic age, rather than in healthy individuals.

"And by the way, this is something we see over and over again with various rejuvenating interventions: they seem to work in people whose epigenetic age is already accelerated, you know, but not in the people who are very healthy." (said at 0:44:46)

Longevity and geroprotective intervention studies frequently demonstrate that reductions in epigenetic age or age acceleration are concentrated in participants who exhibit accelerated epigenetic aging at baseline, whereas individuals who are biologically younger or baseline-normative show minimal to no detectable reduction. For instance, an interventional study assessing a multi-component geroprotective supplement in older adults found no significant overall change across the full cohort, but identified significant reductions in epigenetic age and epigenetic age acceleration specifically among participants with baseline epigenetic age acceleration of at least 2 years.

0:45:47Rhonda Patrick (host)supportedmoderate

Vitamin D deficiency is associated with accelerated epigenetic aging.

"vitamin D deficiency has been shown to be associated with age acceleration." (said at 0:45:47)

Observational and interventional studies have consistently found that vitamin D deficiency or lower serum 25-hydroxyvitamin D concentrations are associated with increased biological age acceleration as measured by various DNA methylation (epigenetic) clocks. For example, cross-sectional analysis from the Berlin Aging Study II (BASE-II, n = 1,649) demonstrated that vitamin D-sufficient individuals had a 1.4-year lower mean DNA methylation age acceleration compared to vitamin D-deficient participants. Furthermore, longitudinal and randomized clinical trials have shown that supplementing vitamin D in deficient or suboptimal individuals is associated with a reduction in epigenetic age acceleration.

0:50:57Steve Horvathsupportedmoderate

For a 50-year-old individual, having a GrimAge of 58 (8 years older than expected) corresponds to more than double the risk of dying in the next year compared to an average person of the same age and sex.

"So, let's start with a 50-year-old um and um let's say their GrimAge is 58, 8 years older than expected. Then their risk of dropping dead in the next year is more than twice that of the average 50-year-old of the same sex." (said at 0:50:57)

In the foundational validation study by Lu et al. (2019) introducing DNAm GrimAge, AgeAccelGrim (the residual metric indicating age acceleration beyond chronological age) was evaluated across large prospective cohort studies (including FHS, WHI, JHS, and InCHIANTI). The hazard ratio for all-cause mortality associated with GrimAge acceleration is approximately 1.10 per year of positive age acceleration (Cox regression P = 2.0E-75). Over an 8-year acceleration gap (e.g., GrimAge of 58 in a 50-year-old), the cumulative hazard ratio equates to 1.10^8 ≈ 2.14, representing more than double the mortality risk compared to an average peer of the same chronological age and sex.

  • supports: DNA methylation GrimAge strongly predicts lifespan and healthspan. (Aging 2019) · cited 2724x in the literature
    "Using large scale validation data from thousands of individuals, we demonstrate that DNAm GrimAge stands out among existing epigenetic clocks in terms of its predictive ability for time-to-death (Cox regression P=2.0E-75), time-to-coronary heart disease (Cox P=6.2E-24), time-to-cancer (P= 1.3E-12), its strong relationship with computed tomography data for fatty liver/excess visceral fat, and age-at-menopause (P=1.6E-12)." (abstract, results, passage verified)
    pubmedfull study (doi)
0:54:29Steve Horvathsupportedmoderate

Epigenetic clocks track several hallmarks of aging, including mitochondrial dysfunction, stem cell changes, nutrient sensing/metabolism, aspects of DNA repair, and shifts in immune cell composition.

"And we know that clocks relate to mitochondrial dysfunction, the energetics. They relate um also to stem cell changes very much so, stem cell biology. Um they um relate to um metabolic changes, nutrient sensing um um to some extent as well, and um and also aspects of DNA repair, you know. So um that is part of the biology. They clearly relate also to changes in what is known as cell composition. So um in in blood we have many different blood cells, and some cells uh are aged, so-called um stressed memory uh T cells, um cytotoxic T cells um um that um are exhausted—this is actually a technical term, exhausted T cells from aging—and conversely there are these naive T cells, you know. So we understand that epigenetic clocks also relate to inflammation and um and that biology." (said at 0:54:29)

Published experimental and epigenetic literature confirms that DNA methylation clocks capture multiple biological hallmarks of aging. Studies evaluating the mechanistic underpinnings of epigenetic age in primary human cell models demonstrate that epigenetic clocks are directly associated with nutrient sensing pathways, mitochondrial activity and energetics, and stem cell composition. Furthermore, blood-based epigenetic clocks (including extrinsic epigenetic age measures) are well-documented to track shifts in leukocyte and immune cell composition, including age-associated declines in naive T cells and increases in exhausted or senescent memory cytotoxic T cell subsets.

0:56:20Steve Horvathsupportedmoderate

DNA methylation clocks do not detect cellular senescence or double-strand breaks induced by gamma radiation in cultured cells.

"You have cells growing in a dish. You irradiate them, high gamma radiation. You induce senescence, they the cells can no longer proliferate. Um, and by the way, radiation leads to double-strand breaks. It really very much stresses the cells. And wouldn't it be nice if methylation clocks picked that up, but they don't, you know. So so radiation damage, at least for— HOST: They don't pick up double-strand breaks even? GUEST1: Yes, at least when you induce it by radiation, you know." (said at 0:56:20)

Published cell culture studies evaluating DNA methylation age estimators (epigenetic clocks) demonstrate that cellular senescence and acute DNA damage response triggered by radiation-induced double-strand breaks do not cause epigenetic age acceleration in cultured cells. Epigenetic clocks track processes that operate independently of radiation-induced DNA damage, telomere shortening, and acute DNA damage-induced senescence.

0:57:15Steve Horvathsupportedmoderate

Epigenetic clocks correlate only weakly with telomere length, and in vitro overexpression of TERT did not reverse epigenetic clock age.

"However, many of the clocks have only a weak correlation with telomere biology. It's a frustrating aspect. Um and um 20 years ago people had an exciting idea: um overexpress a part of telomerase, the TERT, um overexpress TERT. Um and there were companies that pursued that as a rejuvenating intervention, and um in at least in our hands um we did not see a beneficial effect, at least in vitro, you know." (said at 0:57:15)

Published studies confirm both components of the claim. Leukocyte telomere length shows only weak-to-modest correlations with epigenetic clocks (correlation coefficients typically ranging between r = -0.26 and r = -0.49), with no significant association with intrinsic epigenetic age acceleration after multivariable adjustment. Furthermore, in vitro studies by Horvath and colleagues demonstrated that telomerase-immortalized cells and primary human fibroblasts overexpressing human telomerase reverse transcriptase (hTERT) continue to show progressive, linear increases in DNA methylation age as population doublings advance, indicating that TERT overexpression does not halt or reverse epigenetic aging.

1:01:15Steve Horvathsupportedmoderate

The epigenetic age of blood in bone marrow transplant recipients reflects the chronological age of the donor.

"the epigenetic age in a bone marrow transplant recipient often um reflects the age of the donor, you know." (said at 1:01:15)

Studies evaluating DNA methylation (DNAm) age in allogeneic hematopoietic stem cell transplantation (HSCT) recipients demonstrate that the epigenetic age of reconstituted blood primarily reflects the donor's chronological age rather than the recipient's age, maintaining cell-intrinsic epigenetic age patterns even years after transplantation.

1:04:15Steve Horvathsupportedvery low

Heterochronic parabiosis in mice improves cognitive and muscle function and rejuvenates epigenetic clocks across multiple organs, including the liver and kidney.

"when an old mouse is exposed to the circulation of a young mouse, it has multiple benefits: cognitive benefits, also muscle benefits. So um and also, importantly, epigenetic clocks get rejuvenated in many organs. Um so we know that again from several studies, including from Vadim Gladyshev's lab, but others have found that too. So yes, um young circulation rejuvenates the liver, the kidney, all of that, you know, um on the methylation level." (said at 1:04:15)

Preclinical rodent studies have shown that heterochronic parabiosis (pairing the circulatory systems of young and old mice) improves tissue function and reverses biological age markers. Research from Vadim Gladyshev's laboratory and collaborators demonstrated that extended heterochronic parabiosis significantly lowers biological and epigenetic clock age in multiple tissues (including blood and liver) and yields transcriptomic and epigenomic rejuvenation that persists following surgical detachment. Because this evidence is exclusively derived from animal models, the GRADE certainty is very low.

1:06:00Rhonda Patrick (host)supportedhigh

The CALERIE study was a two-year randomized controlled trial evaluating a 25% caloric restriction intervention in humans.

"This was a two-year randomized controlled trial where individuals were basically eating 25% fewer calories than they otherwise would or they were eating their normal, you know, daily food intake as as usual." (said at 1:06:00)

The CALERIE Phase 2 study (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) was a two-year multicenter randomized controlled trial conducted in healthy, non-obese human adults (aged 21–51 years). Participants were randomized (2:1 ratio) to either a prescribed 25% calorie restriction diet intervention or an ad libitum control diet.

1:07:50Steve Horvathsupportedhigh

In the CALERIE trial, the GrimAge and PhenoAge clocks did not detect a significant anti-aging effect, but the DunedinPACE clock showed a 2% to 3% slowing of the rate of aging.

"GrimAge and PhenoAge did not pick up an effect. But this new clock, a new clock at the time, DunedinPACE, really picked up an effect... The like a 2 to 3% slowing of the rate of aging over the two years." (said at 1:07:50)

A post hoc analysis of the phase 2 CALERIE randomized controlled trial evaluated the effect of 2 years of caloric restriction versus an ad libitum diet on DNA methylation measures of biological aging in 220 healthy, non-obese adults. The analysis found that caloric restriction significantly slowed the pace of biological aging as measured by DunedinPACE (by approximately 2% to 3%), but did not show statistically significant changes in biological age estimates measured by static epigenetic clocks such as GrimAge and PhenoAge.

1:18:30Rhonda Patrick (host)supportedhigh

In the main COSMOS randomized controlled trial, multivitamin supplementation showed no statistically significant reduction in hard clinical endpoints like all-cause mortality, cancer mortality, or cardiovascular disease.

"the COSMOS trials people they're looking at everything, right? Cancer mortality, cardiovascular mortality, all-cause mortality, and those didn't really seem to change, yes, at least within the time frame, yes, that was looked at." (said at 1:18:30)

In the large-scale COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized controlled trial (21,442 older adults followed for a median of 3.6 years), daily multivitamin-multimineral supplementation showed no statistically significant reduction compared to placebo in total invasive cancer (HR 0.97, 95% CI 0.86–1.09), composite cardiovascular disease events (HR 0.98, 95% CI 0.86–1.12), or all-cause mortality (HR 0.93, 95% CI 0.81–1.08).

1:23:15Rhonda Patrick (host)supportedmoderate

Approximately 90% of Americans do not consume sufficient amounts of omega-3 fatty acids.

"90% of Americans don't get enough omega-3 fatty acids. Nobody's eating seafood in the US." (said at 1:23:15)

Nationally representative analyses from the National Health and Nutrition Examination Survey (NHANES) support the claim. An evaluation of NHANES 2003–2008 data (n = 24,621) found that over 90% of the US population consumed less than the American Heart Association-recommended 0.5 g/day of long-chain omega-3 fatty acids (EPA + DHA) from food sources. Biomarker evaluations from NHANES also demonstrate that 80.6% to 95.7% of US adults have plasma long-chain omega-3 concentrations below thresholds associated with cardiovascular health and cardioprotection.

1:24:17Steve Horvathsupportedhigh

In the DO-HEALTH randomized controlled trial of 780 older adults led by Heike Bischoff-Ferrari, 1 gram daily of omega-3 slowed epigenetic aging as measured by GrimAge v2, PhenoAge, and DunedinPACE.

"This was a study conducted by a Swiss professor, Heike Bischoff-Ferrari, who looked at 780 people and um followed, again, the most rigorous um design: randomized controlled trial, placebo-controlled trial in a population that I was very interested in, people 71 years or older... The most credible result was omega-3 on epigenetic clocks. A couple of epigenetic clocks picked it up: GrimAge version two, PhenoAge, DunedinPACE also worked very well in that context." (said at 1:24:17)

A 2025 analysis of the DO-HEALTH randomized controlled trial led by Heike Bischoff-Ferrari examined 777 older adults (aged 70+) over 3 years. The study found that 1 g per day of omega-3 supplementation slowed biological aging as measured by three next-generation DNA methylation clocks: PhenoAge, GrimAge2, and DunedinPACE, with overall standardized slowing effects ranging from 2.9 to 3.8 months across clocks.

1:25:30Steve Horvathsupportedmoderate

In the DO-HEALTH trial, high-dose vitamin D (2000 IU vs 800 IU) alone and home resistance exercise alone showed no significant effect on epigenetic clocks.

"high vitamin D was 2,000 IUs... And the low was 800 IUs... results for vitamin D were disappointing. No effect on epigenetic clocks... this home exercise intervention was very modest... no effect. I was very disappointed." (said at 1:25:30)

In a post hoc randomized controlled analysis of 777 older adults from the DO-HEALTH trial (PMID: 39900648), the effects of vitamin D3 (2,000 IU/day), omega-3 fatty acids (1 g/day), and a simple home exercise program were assessed on four epigenetic clocks of biological aging (PhenoAge, GrimAge, GrimAge2, and DunedinPACE) over 3 years. While omega-3 alone significantly slowed aging across several clocks and the three interventions showed an additive benefit on PhenoAge, neither vitamin D alone nor the home exercise program alone demonstrated a statistically significant individual effect on slowing the epigenetic clocks.

1:33:00Rhonda Patrick (host)supportedhigh

Magnesium is required to convert vitamin D3 into active steroid hormone.

"There's other micronutrients: magnesium really affects vitamin D. You need magnesium to convert vitamin D3 into, you know, the steroid hormone." (said at 1:33:00)

The claim is supported by established biochemistry and clinical literature. Magnesium acts as an essential cofactor for the enzymatic conversion of vitamin D into its biologically active steroid hormone form, 1,25-dihydroxyvitamin D (calcitriol). Both the hepatic 25-hydroxylation step (converting cholecalciferol/vitamin D3 to 25-hydroxyvitamin D) and the subsequent renal 1α-hydroxylation step (converting 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D), as well as the activity of vitamin D-binding protein, require magnesium.

1:36:03Steve Horvathsupportedmoderate

Smoking has a positive correlation of 0.4 to 0.45 with GrimAge epigenetic age acceleration.

"smoking has a correlation of 0.4. So, if you smoke a lot, it increases your age... smoking 0.4, maybe 0.45. So it's increased correlation." (said at 1:36:03)

DNAm GrimAge is an epigenetic biomarker of mortality and biological aging that explicitly incorporates DNA methylation surrogate markers, including a DNA methylation-based estimator of smoking pack-years (DNAm PACKYRS). In published validation and cohort studies evaluating lifestyle associations with epigenetic clocks, cigarette smoking and pack-years consistently exhibit a moderate-to-strong positive correlation (typically r ≈ 0.40–0.45) with GrimAge and GrimAge epigenetic age acceleration (AgeAccelGrim), explaining a substantial portion of the variance in GrimAge acceleration.

1:36:20Steve Horvathsupportedlow

Physical activity measured by step counts has an inverse correlation of approximately -0.1 with epigenetic clocks such as GrimAge.

"exercise, the correlation would be 0.1. So, do you see? So vegetable intake has a much stronger effect, I mean orders of magnitude stronger effect on GrimAge and these methylation clocks than, for example, exercise, you know... yes, if you move more, yes, your epigenetic clocks um pick up a small effect, and I mentioned earlier correlation minus 0.1." (said at 1:36:20)

Epidemiological studies examining DNA methylation clocks (including GrimAge) consistently find that physical activity and exercise metrics have only modest to weak inverse associations with epigenetic age acceleration (typically correlation coefficients or standardized betas around r ≈ -0.10, or modest reductions in epigenetic age of a fraction of a year). Lifestyle factors such as smoking, BMI, and certain dietary markers tend to exhibit significantly larger association sizes with GrimAge than physical activity.

1:39:48Steve Horvathsupportedmoderate

An analysis of 3,000 women in the Women's Health Initiative showed that red meat consumption had only a negligible, barely noticeable effect on increasing epigenetic age.

"We looked again in the Women's Health Initiative. I mean, there was a hint, I want to say, when we analyzed 3,000 women, and then women who ate red meat, it was barely noticeable that red meat was ever so slightly increasing epigenetic age, but it was truly negligible, you know." (said at 1:39:48)

In published analyses of epigenetic clocks in postmenopausal women from the Women's Health Initiative (WHI; ~4,000 participants), red meat intake showed either non-significant or negligible associations with biological age acceleration compared to factors like metabolic health, BMI, and overall diet quality. Significant dietary associations were primarily driven by fish, poultry, processed meats, and plant-derived nutrients rather than overall red meat consumption.

  • supports: Epigenetic clock analysis of diet, exercise, education, and lifestyle factors. (Aging 2017) · cited 901x in the literature
    "We analyze cross-sectional data from 4,173 postmenopausal female participants from the Women's Health Initiative, as well as 402 male and female participants from the Italian cohort study, Invecchiare nel Chianti. Extrinsic epigenetic age acceleration (EEAA) exhibits significant associations with fish intake (p=0.02), moderate alcohol consumption (p=0.01), education (p=3x10 -5 ), BMI (p=0.01), and blood carotenoid levels (p=1x10 -5 )-an indicator of fruit and vegetable consumption, whereas intrinsic epigenetic age acceleration (IEAA) is associated with poultry intake (p=0.03) and BMI (p=0.05)." (abstract, results, passage verified)
    pubmedfull study (doi)
1:41:06Rhonda Patrick (host)supportedmoderate

A 2025 study by lead author Vanam found that 6 months of cycling for 4.5 hours per week improved VO2 max by 20% and reduced PC-GrimAge by approximately 7 to 7.4 months.

"and it was kind it was a new one in 2025 showing that 6 months of cycling, it seemed to slow epigenetic aging or GrimAge, right? GrimAge by 7.4 months... this study that was published um by first author I can remember Vanam... It was putting people on a bicycle and they now um bicycled 4 and 1/2 hours a week... they had strong effects on VO2 max, 20% 20%... it picked up a 7-month reduction in GrimAge" (said at 1:41:06)

A clinical study evaluating a 6-month cycling endurance exercise training intervention in 42 adults aged 35-65 found that cardiorespiratory fitness (VO2 max) improved by 20% (P < 0.001) and biological age measured by the GrimAge epigenetic clock decreased by an average of 7.44 months relative to the expected trajectory (P = 0.012). The reduction in GrimAge correlated with the gains in VO2 max.

  • supports: Epigenetic age deceleration reflects exercise-induced cardiorespiratory fitness improvemen… (GeroScience 2026) · cited 5x in the literature
    "This pilot study investigates whether the GrimAge clock can capture the effects of a 6-month cycling-based endurance exercise training intervention, with cardiorespiratory fitness (VO 2 max) and body composition as primary outcomes. We enrolled 42 adults aged 35-65, of whom 38 completed the study and 33 adhered to the protocol (> 66% adherence). Participants demonstrated significant improvements in VO 2 max (+ 20%, P < 0.001) and body composition (P < 0.001)... On average, GrimAge decreased by 7.44 months relative to the expected trajectory (P = 0.012), reflecting improvements in VO 2 max (R 2 = 0.27, P = 0.002) but not body composition changes." (abstract, results, passage verified)
    pubmedfull study (doi)
1:44:05Rhonda Patrick (host)supportedmoderate

A two-year exercise trial led by Dr. Benjamin Levine in 50-year-olds improved VO2 max and reversed cardiac structural stiffening and aging by approximately 20 years.

"he did one that was a two-year study in 50-year-olds. They were about 50-year-olds and they had never been physically active, but they didn't have any other diseases. Put them on a a two-year trial where they were working out, exercising about five on average 5 hours a week, doing a lot of cycling... they improved the structure of their hearts by it was like if you basically it looked like they reversed aging by about 20 years. Their hearts, you know, got bigger and they were more flexible and it looked more like a 30-year-old even though they were 52 at the end of the trial." (said at 1:44:05)

A randomized controlled trial led by Dr. Benjamin Levine (Howden et al., 2018) evaluated the effects of 2 years of supervised exercise training (4-5 sessions per week, progressive high-intensity and endurance training) versus an attention control in 61 healthy, sedentary middle-aged adults (mean age 53 ± 5 years). The trial found that 2 years of exercise increased VO2 max by 18% and significantly decreased left ventricular stiffness (reversing the leftward shift in end-diastolic pressure-volume curves), increasing left ventricular compliance and end-diastolic volume toward profiles typically seen in healthy younger individuals (~30 years of age). Evidence certainty is rated moderate due to sample size constraints.

  • supports: Reversing the Cardiac Effects of Sedentary Aging in Middle Age-A Randomized Controlled Tri… (Circulation 2018) · cited 217x in the literature
    "Sixty-one (48% male) healthy, sedentary, middle-aged participants (53±5 years) were randomly assigned to either 2 years of exercise training (n=34) or attention control (control; n=27)... Vo 2 max increased by 18% (exercise training: pre 29.0±4.8 to post 34.4±6.4; control: pre 29.5±5.3 to post 28.7±5.4, group×time P <0.001) and LV stiffness was reduced (right/downward shift in the end-diastolic pressure-volume relationships; preexercise training stiffness constant 0.072±0.037 to postexercise training 0.051±0.0268, P =0.0018), whereas there was no change in controls" (abstract, results)
    pubmedfull study (doi)
1:48:38Steve Horvathsupportedvery low

Stimulating preoptic neurons in mice to lower their core body temperature by approximately 3°C significantly slowed epigenetic aging across multiple organs.

"if you stimulate certain neurons in the brain, the uh preoptic area, I think, you can actually lower the body temperature of a mouse. And um there was a team in Harvard, um Sinisa Hrvatin, who did just that in the mice, and he lowered the body temperature of the mice, I want to say by 3° C or some order of magnitude, and then he just looked at their methylation clocks, multiple organs, and guess what? Very strong effect. So the mice whose body temperature was lowered, they really aged substantially more slowly than a control mouse." (said at 1:48:38)

The speaker accurately summarizes published experimental work from Sinisa Hrvatin and colleagues. In mouse models, chemogenetic activation of specific neurons in the preoptic area induced a hypothermic, torpor-like state (TLS). Prolonged induction of this state significantly decelerated epigenetic aging across multiple tissues (assessed via DNA methylation clocks) and extended healthspan, with the deceleration mediated by reduced core body temperature. Because this evidence is restricted to pre-clinical mouse models, the overall GRADE certainty is very low for translation to human biology.

  • supports: Neurons that regulate mouse torpor. (Nature 2020) · cited 302x in the literature
    "Here we show that entry into mouse torpor, a fasting-induced state with a greatly decreased metabolic rate and a body temperature as low as 20 °C, is regulated by neurons in the medial and lateral preoptic area of the hypothalamus. We show that restimulation of neurons that were activated during a previous bout of torpor is sufficient to initiate the key features of torpor, even in mice that are not calorically restricted." (abstract)
    pubmedfull study (doi)
  • supports: A torpor-like state in mice slows blood epigenetic aging and prolongs healthspan. (Nature aging 2025) · cited 19x in the literature
    "Here we demonstrate that the activity of a spatially defined neuronal population in the preoptic area, which has previously been identified as a torpor-regulating brain region, is sufficient to induce a torpor-like state (TLS) in mice. Prolonged induction of TLS slows epigenetic aging across multiple tissues and improves healthspan. We isolate the effects of decreased metabolic rate, long-term caloric restriction, and decreased core body temperature (T b ) on blood epigenetic aging and find that the decelerating effect of TLSs on aging is mediated by decreased T b ." (abstract, passage verified)
    pubmedfull study (doi)
1:49:52Steve Horvathsupportedvery low

A UCLA study on marmots during hibernation found that DNA methylation clocks did not advance while the animals hibernated.

"During hibernation, animals that hibernate, yeah, same thing. There have been a couple of studies that um suggest um that there's um a slowing of aging. Um we did such a study at UCLA. We looked at marmots in um Colorado, I think. Um and um sure enough, during hibernation, the methylation clocks um didn't advance, you know." (said at 1:49:52)

A 2022 study by UCLA researchers (Pinho et al., published in Nature Ecology & Evolution) evaluated epigenetic aging in free-ranging yellow-bellied marmots in Colorado using DNA methylation models. They observed that epigenetic aging advanced during the active season and essentially stalled while the animals hibernated.

1:51:25Steve Horvathsupportedlow

Observational research by Judith Carroll in the Women's Health Initiative cohort found that severe sleep disturbances are associated with increased epigenetic age.

"I worked with a team at UCLA, uh, Judith Carroll, um, and she looked at sleep disturbances in the Women's Health Initiative, um, and other cohorts. And sure enough, um, people who report severe sleep disruptions, these people exhibited increased epigenetic age." (said at 1:51:25)

A 2017 observational study led by Judith Carroll using data from the Women's Health Initiative (WHI) cohort (N = 2,078 postmenopausal women) evaluated the association between sleep parameters and biological aging measured via DNA methylation (epigenetic clock). Insomnia symptoms (such as restless sleep, difficulty initiating sleep, nighttime awakenings, and early awakenings) were significantly associated with accelerated epigenetic age after adjusting for covariates (β = 1.02, p = 0.005). Because the analysis was observational and cross-sectional, certainty is rated as low.

1:52:53Steve Horvathsupportedlow

Research by Laura Kubzansky showed that cumulative social advantage and community connectedness significantly reduced GrimAge epigenetic aging.

"there was a um researcher at Harvard, um Laura Kubzansky or I I butcher her last name, but um she is um a very rigorous scientist, and she wanted to evaluate whether what she calls uh I think a social cumulative advantage, um which is a measure of um how connected you are in the community, your social behavior, your your friends, your community. Anyways, how does that affect biologic aging?... GrimAge again picked it up. People who have this uh who are blessed really by having wonderful family relations, community, just this social advantage, you know. Sure enough, their GrimAge was reduced." (said at 1:52:53)

A cohort study of 2,117 adults from the Midlife in the United States (MIDUS) study, co-authored by Laura Kubzansky, evaluated the association between cumulative social advantage (a latent construct capturing familial, religious, emotional, and community connection) and biological aging. The study found that higher cumulative social advantage was significantly associated with slower epigenetic aging as measured by the GrimAge clock (β = -0.09 to -0.10, q < 0.001) as well as DunedinPACE. Because this is observational data, certainty is rated as low.

1:37:14Rhonda Patrick (host)supportedmoderate

Lutein and zeaxanthin accumulate in the human brain and are associated with improved cognitive function, crystallized intelligence, and reduced brain aging.

"They also accumulate in the brain, and they're associated with improved cognitive function, crystallized intelligence, improved brain aging in general, all right." (said at 1:37:14)

Lutein and zeaxanthin cross the blood-brain barrier and selectively accumulate in human neural tissue, where lutein represents the predominant carotenoid across the lifespan. Observational and intervention studies have linked higher lutein/zeaxanthin levels and macular pigment optical density to better overall cognitive performance and specific cognitive domains. Furthermore, research in older adults has specifically identified an association between serum lutein concentrations and crystallized intelligence, partially mediated by preservation of gray matter thickness in temporal brain regions such as the parahippocampal cortex.

1:48:09Rhonda Patrick (host)supportedlow

Head-to-head comparison trials show that a 20-minute sauna session induces cardiovascular and physiological effects comparable to 20 minutes of cycling on a stationary bike at approximately 100 watts, including heart rate elevation and blood pressure improvements.

"There's been head-to-head comparisons with like getting on a stationary bike and, you know, doing about 100 watts. So, you're for 20 minutes and then comparing that to like a 20-minute sauna and you get a lot of the similar benefits. You get improvements in blood pressure, improvements in your resting heart rate, [snorts] you get, you know, again, you're sweating, your core body temperature is going up." (said at 1:48:09)

A clinical study directly comparing the acute hemodynamic responses of a sauna session (25 minutes at 93°C) with submaximal dynamic exercise testing on a stationary bike found that heart rate and blood pressure responses during the sauna session corresponded to an exercise load of 60 to 100 watts. Following heat exposure, participants experienced reductions in blood pressure below baseline levels. However, this evidence is derived from a small physiological trial (n=19 healthy adults) measuring acute, short-term effects.

2:08:51Steve Horvathsupportedmoderate

Principal component-based epigenetic clocks, such as PC-GrimAge, have high technical reproducibility with test-retest technical variation of only a few months.

"these principal component-based versions of clocks, such as PC-GrimAge that was used in the COSMOS multivitamin study. Anyway, these are very reproducible. And to give you a number, let's say you measured that marker two days apart. You measure PC-GrimAge on Monday and then another measure on Wednesday, and nothing has happened. I would expect a technical variation of maybe four or five months, perhaps, and/or two months. It's a few months, you know, and so this is just technical variance" (said at 2:08:51)

Principal component-based (PC) epigenetic clocks, including PC-GrimAge, were developed specifically to address the technical noise and poor test-retest reliability of standard DNA methylation clocks. Standard epigenetic clocks can exhibit replicate deviations of up to 9 years due to technical noise, whereas principal component versions markedly improve test-retest reproducibility, narrowing differences between replicates to within 1.5 years and typical technical variation down to several months.

  • supports: A computational solution for bolstering reliability of epigenetic clocks: Implications for… (Nature aging 2022) · cited 527x in the literature
    "Here we show technical noise produces deviations up to 9 years between replicates for six prominent epigenetic clocks, limiting their utility. We present a computational solution to bolster reliability, calculating principal components from CpG-level data as input for biological age prediction. Our retrained principal-component versions of six clocks show agreement between most replicates within 1.5 years, improved detection of clock associations and intervention effects, and reliable longitudinal trajectories in vivo and in vitro ." (abstract, passage verified)
    pubmedfull study (doi)
2:10:05Steve Horvathsupportedmoderate

The Horvath pan-tissue epigenetic clock tracks stem cell biology, hematopoietic stem cells, and leukemia precursors, but is not good for predicting mortality risk.

"The Horvath pan-tissue clock is very good for stem cell biology, hematopoietic stem cells, precursors of leukemia, that type of biology; just not good for mortality risk, you know." (said at 2:10:05)

The speaker accurately characterizes the utility of Steve Horvath's original 2013 pan-tissue DNA methylation clock. First-generation epigenetic clocks were trained directly on chronological age across multiple tissue types, making them sensitive to cellular mitotic history, stem cell biology, pluripotency resetting (such as embryonic stem cells and induced pluripotent stem cells having a methylation age near zero), and hematopoiesis. However, large comparative studies demonstrate that first-generation clocks perform poorly compared to second- and third-generation clocks (such as DNAm PhenoAge and DNAm GrimAge) for predicting incident disease and all-cause mortality risk.

2:13:13Steve Horvathsupportedhigh

Reprogramming somatic cells using Yamanaka factors reverses their epigenetic age to a prenatal, negative value on the pan-tissue DNA methylation clock.

"So back in 2013, I published the pan-tissue clock. Figure 5 in that paper showed Yamanaka factors reversed the age to a prenatal state. So you take a skin cell from a 50-year-old, and the epigenetic age of an induced pluripotent stem cell is a negative number, meaning prenatal, you know." (said at 2:13:13)

Steve Horvath's landmark 2013 paper describing the multi-tissue DNA methylation clock demonstrated that reprogramming somatic cells into induced pluripotent stem cells (iPSCs) via Yamanaka factors resets their epigenetic age to an embryonic/prenatal baseline, typically resulting in values near or below zero on the clock.

2:23:45Steve Horvathsupportedhigh

When somatic cells are reprogrammed into induced pluripotent stem cells, somatic DNA mutations are retained and persist.

"If we talk about the extreme case of making an induced pluripotent stem cell, do the somatic mutations persist in that as well? GUEST1: Yes." (said at 2:23:45)

The claim is supported. High-resolution whole-exome sequencing and genomic analyses show that pre-existing somatic mutations present in parent somatic cells are retained and persist when cells are reprogrammed into induced pluripotent stem cells (iPSCs). Additionally, cellular reprogramming can enrich for certain pre-existing somatic mutations present in subpopulations of the parental cells.

2:24:20Steve Horvathsupportedhigh

As humans age, all cells throughout the body accumulate somatic mutations.

"what happens as we age: all cells in your body accumulate somatic mutations. They really do" (said at 2:24:20)

High-throughput single-cell and bulk whole-genome sequencing studies have consistently demonstrated that normal cells across both dividing (e.g., skin, intestine, hematopoietic system) and postmitotic/non-dividing human tissues (e.g., neurons, cardiomyocytes) progressively accumulate somatic DNA mutations throughout life in a clock-like manner.

2:28:51Rhonda Patrick (host)supportedhigh

Resistance training helps individuals maintain and increase muscle mass.

"We know resistance training absolutely helps you not only maintain but increase your muscle mass, and that's hugely important for life expectancy and quality of life." (said at 2:28:51)

A extensive body of randomized controlled trials and systematic reviews confirms that resistance training increases and maintains skeletal muscle mass across young, middle-aged, and older populations. Meta-analyses demonstrate consistent gains in muscle cross-sectional area and lean mass across various loading protocols and training volumes, as well as significant increases in appendicular skeletal muscle mass among older adults counteracting age-related muscle loss.

2:05:57Steve Horvathsupportedhigh

DNA methylation patterns can be used to construct organ-specific biological age estimators for individual organs such as the heart, kidney, and lung.

"people use methylation to estimate the ages of different organs, you know, so it's a heart measure, but they will say your kidney is older or your lung, you know, so that's where the field is at, developing um organ-specific methylation markers" (said at 2:05:57)

DNA methylation patterns have been extensively validated to construct both pan-tissue and organ/tissue-specific biological age estimators across human and mammalian tissues (including heart, kidney, lung, and others). Meta-analyses of thousands of tissue methylation profiles demonstrate that DNA methylation changes exhibit distinct organ-specific epigenetic signatures of aging alongside systemic pan-tissue patterns.

2:13:42Steve Horvathsupportedhigh

Ake Lu and colleagues published the DNAm GrimAge epigenetic clock in 2019.

"Ake Lu in the lab published GrimAge 2019, way before ChatGPT, before anything." (said at 2:13:42)

Ake T. Lu and colleagues (including Steve Horvath) published the landmark paper introducing the DNA methylation GrimAge clock ("DNA methylation GrimAge strongly predicts lifespan and healthspan") in the journal Aging in January 2019.

2:00:25Steve Horvathsupportedmoderate

Partial or interrupted cellular reprogramming with Yamanaka factors does not restore telomere length.

"I seem to remember one aspect that wasn't restored was telomere length, so that wasn't." (said at 2:00:25)

Complete reprogramming into induced pluripotent stem cells (iPSCs) fully reactivates telomerase and elongates telomeres alongside resetting epigenetic clocks. In contrast, partial or interrupted cellular reprogramming (transient exposure to Yamanaka factors Oct4, Sox2, Klf4, and c-Myc) reverses transcriptomic aging and resets DNA methylation clocks while preserving cell identity, but does not induce full telomere elongation or restoration, though it may stabilize existing telomere length.

2:01:40Steve Horvathsupportedvery low

DNA methylation clocks detect rejuvenation effects from interrupted cellular reprogramming in some tissues, such as skin and muscle, but not across all organs.

"methylation clocks do detect a benefit of interrupted reprogramming in certain organs, but not all... in skin there was a strong effect, I want to say also muscle, you know, it's just not all organs." (said at 2:01:40)

Animal and cellular studies demonstrate that interrupted (partial or transient) cellular reprogramming with Yamanaka factors (OSKM) leads to tissue- and regimen-specific reversals of epigenetic age measured by DNA methylation clocks. For example, long-term cyclic in vivo partial reprogramming in aging mice reversed epigenetic aging signatures in tissues such as skin and kidney, but effects varied across organs and treatment durations. Because these findings are derived entirely from preclinical mouse models and in vitro cell culture, certainty in human clinical contexts remains very low.

2:32:15Steve Horvathsupportedhigh

The APOE4 allele is strongly associated with Alzheimer's disease.

"I mean, they are famous association APOE4 for Alzheimer's. There's strong association" (said at 2:32:15)

Large-scale meta-analyses and extensive genetic epidemiology establish that the APOE ε4 (APOE4) allele is the strongest known genetic risk factor for late-onset Alzheimer's disease. Carrying a single ε4 allele substantially increases the odds of developing Alzheimer's disease (odds ratios typically between 2.5 and 3.5), and carrying two alleles (ε4/ε4 homozygosity) increases the risk by roughly 7- to 15-fold depending on ancestral background.

2:34:04Steve Horvathsupportedhigh

Many people who carry the APOE4 allele do not develop Alzheimer's disease, and many people with Alzheimer's disease do not carry the APOE4 allele.

"I mean, there's a lot of people that have APOE4 that do not have Alzheimer's disease, and there's a lot of people with Alzheimer's disease that do not have an APOE4 allele." (said at 2:34:04)

The claim is well supported by epidemiological and genetic studies of Alzheimer's disease (AD). Although the APOE ε4 allele is the strongest common genetic risk factor for late-onset AD, it is neither necessary nor sufficient to cause the disease. Approximately 24% of non-demented community-dwelling adults carry an APOE ε4 allele (mostly heterozygous ε3/ε4), and the majority of ε4 carriers do not develop AD. Furthermore, a substantial proportion of individuals diagnosed with Alzheimer's disease do not carry an APOE ε4 allele, as the presence of ε4 increases disease odds but does not account for all cases.

2:37:54Rhonda Patrick (host)supportedhigh

Statins inhibit the mevalonate pathway (HMG-CoA reductase), which is responsible for cholesterol synthesis and CoQ10 production in mitochondria.

"statins target the mevalonate pathway, which is HMG-CoA, important for cholesterol synthesis. That's why it's the most widely prescribed drug for lowering LDL cholesterol, but also that pathway is important for making CoQ10 in your mitochondria." (said at 2:37:54)

The speaker's statement accurately reflects established pharmacology and biochemistry. Statins competitively inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme of the mevalonate pathway. This pathway produces not only cholesterol (leading to upregulation of LDL receptors and lowering of circulating LDL cholesterol), but also isoprenoid intermediates (such as farnesyl pyrophosphate) necessary for the biosynthesis of coenzyme Q10 (ubiquinone), an essential component of the mitochondrial electron transport chain.

  • supports: Statins Limit Coenzyme Q Synthesis and Metabolically Synergize with MEK Inhibition in Panc… (Cancer research 2020) · cited 19x in the literature
    "Tumors frequently increase expression of enzymes in the mevalonate biosynthesis pathway. Statins inhibit flux through this pathway, but if and how such treatments elicit a therapeutic benefit in cancer remains unclear. In this issue of Cancer Research , McGregor and colleagues perform in vivo metabolic tracing to demonstrate that mouse pancreatic ductal adenocarcinoma (PDAC) tumors and human PDAC cell lines require this pathway for coenzyme Q (CoQ) synthesis and redox homeostasis. Simvastatin treatment reduces CoQ synthesis and promotes oxidative stress and apoptosis in tumors" (abstract, passage verified)
    pubmedfull study (doi)
  • supports: Effects of statins on mitochondrial pathways. (Journal of cachexia, sarcopenia and muscle 2021) · cited 246x in the literature
    "They inhibit β-hydroxy β-methylglutaryl-coenzyme A reductase, i.e. the rate-limiting enzyme in mevalonate pathway, reduce endogenous cholesterol synthesis, and increase low-density lipoprotein clearance by promoting low-density lipoprotein receptor expression mainly in the hepatocytes... Results have shown that statins have several effects on mitochondria including reduction of coenzyme Q10 level, inhibition of respiratory chain complexes, induction of mitochondrial apoptosis, dysregulation of Ca 2+ metabolism, and carnitine palmitoyltransferase-2 expression." (abstract, passage verified)
    pubmedfull study (doi)
2:38:24Rhonda Patrick (host)supportedhigh

Ubiquinol is the reduced form of CoQ10, while ubiquinone is the oxidized form.

"So taking CoQ10, I say ubiquinol, it's the reduced form, ubiquinone also does the does the trick" (said at 2:38:24)

Coenzyme Q10 exists in two primary interconvertible redox states: ubiquinone is the fully oxidized form and ubiquinol is the fully reduced form. Both forms participate continuously in cellular bioenergetics and redox homeostasis.

2:40:02Steve Horvathsupportedmoderate

Severe psychological stress such as childhood sexual abuse and PTSD has been shown in the literature to affect epigenetic age acceleration.

"there's some literature that really severe psychological stress, we're talking now childhood sexual abuse, perhaps even PTSD, that affects your epigenetic age." (said at 2:40:02)

Published literature supports the claim that severe psychological stressors, including childhood trauma and PTSD severity, are associated with altered epigenetic age and accelerated DNA methylation aging. A meta-analysis of 9 cohorts (N = 2,186) by the Psychiatric Genomics Consortium PTSD Epigenetics Workgroup found that childhood trauma exposure and lifetime PTSD symptom severity were significantly associated with accelerated DNA methylation age, though effect sizes were modest. Longitudinal cohort studies have also demonstrated that childhood adversity, including abuse, is associated with accelerated epigenetic aging.

2:39:48Steve Horvathsupportedmoderate

Short-term psychological stress does not significantly affect epigenetic clocks.

"the hopeful message about stress is that short-term stress does not seem to affect epigenetic clocks, psychological stress." (said at 2:39:48)

Published studies examining stress and epigenetic clocks indicate that while chronic psychological stress, depression, and trauma are reliably associated with accelerated epigenetic aging across various clocks (such as GrimAge and PhenoAge), acute or short-term psychological stress reactivity per se does not show a significant direct effect on epigenetic age acceleration. In an experimental acute laboratory stress study measuring epigenetic markers before and after stress exposure, psychological stress reactivity did not predict changes in epigenetic aging clocks (though physiological cortisol reactivity showed associations). Systematic reviews and meta-analyses consistently confirm that epigenetic age acceleration is driven by long-term, cumulative psychological adversity and chronic stress rather than transient, short-term psychological stress events.

5

No source found (not proven false)

0:26:50Steve Horvathunverifiedvery low

Applying the Horvath pan-tissue clock to sperm yields a constant uninformative value of approximately 37 across individuals.

"So for example, what is known as the Horvath pan-tissue clock, you apply to sperm you get one number: 37 or so, [laughter] but everybody has the same number in essence, you know, uninformative." (said at 0:26:50)

No published record matching the claim that applying the Horvath pan-tissue clock to sperm yields a constant value of approximately 37 across individuals was located; this does not prove the claim false.

0:38:03Steve Horvathunverifiedvery low

The FDA has not approved or qualified any aging biomarker as an official surrogate endpoint for clinical trials.

"the biomarker field has not yet developed any biomarker that is credible to the FDA when it comes to this ambition of being an official surrogate endpoint of a clinical trial." (said at 0:38:03)

No published record matching the claim that the FDA has not approved or qualified any aging biomarker as an official surrogate endpoint for clinical trials was located; this does not prove the claim false.

0:41:06Steve Horvathunverifiedvery low

Anti-TNF-alpha therapy reverses epigenetic age in patients with autoimmune disease.

"So the other intervention that has very strong evidence is anti-TNF-alpha therapy, really anti-inflammatory drugs for people who have an autoimmune disease." (said at 0:41:06)

No published record matching the claim that anti-TNF-alpha therapy reverses epigenetic age in patients with autoimmune disease was located; this does not prove the claim false. Published studies on DNA methylation and epigenetic clocks in autoimmune conditions (such as psoriasis and rheumatoid arthritis) have examined cross-sectional differences in epigenetic age acceleration or predicted treatment response based on baseline DNA methylation patterns (e.g., PMID: 33015854, PMID: 37698382, PMID: 39797936), but direct longitudinal published evidence demonstrating reversal of epigenetic age following anti-TNF-alpha therapy in human patients was not found in PubMed or Europe PMC.

1:02:20Steve Horvathunverifiedvery low

In animal transplantation experiments by Vadim Gladyshev's group, replacing blood or stem cells with those from a young mouse did not rejuvenate other organs, and the transplanted stem cells aged in the old recipient.

"They didn't rejuvenate other organs. If anything, there was um a disappointing result that um after x number of months, actually the stem cells had aged. So the body has the memory of the old mouse, and that then aged the the the blood." (said at 1:02:20)

No published record matching the claim that Vadim Gladyshev's group conducted stem cell or blood transplantation experiments in which young stem cells aged in the old recipient body without rejuvenating other organs was located; this does not prove the claim false.

1:12:43Steve Horvathunverifiedvery low

In a multivitamin trial analysis (COSMOS subset), GrimAge and PhenoAge detected a statistically significant deceleration of epigenetic aging of 2.7 to 5 months over 2 years, whereas DunedinPACE did not reach statistical significance.

"here GrimAge found an effect, PhenoAge found an effect based on multivitamin use, but DunedinPACE failed. It was not significant, you know... When it comes to looking at these epigenetic aging clocks, the PhenoAge and GrimAge clocks were the ones that stood out to me. As you mentioned, there was a battery of clocks that were that were looked at, but it seemed as though they were slowing, or at least—I'm not exactly sure all the calculations that go into this—but 2.7 months to 5 months, right? Like they were basically they're they're slowing the aging by roughly that amount." (said at 1:12:43)

No published record matching the specific epigenetic clock findings (GrimAge, PhenoAge, and DunedinPACE deceleration effects) in the multivitamin trial analysis was retrieved in full; this does not prove the claim false.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.