Heart-Healthy Habits Slow the Epigenetic Clock — But Not All Equally
A new Korean cohort study ranks which of the eight cardiovascular health pillars move the biological-age needle most — and the answer differs by sex.
For the better part of a decade, longevity-minded readers have been trading wearables data, fasting protocols, and DNA-methylation reports in pursuit of a single number: biological age. The promise of the epigenetic clock — that the chemical tags on our DNA can be read like an odometer — has reshaped how we think about prevention. But the field has been long on hype and short on a question every self-quantifier eventually asks: of all the lifestyle levers we are told to pull, which ones actually slow the clock the most? A new analysis out of South Korea offers the cleanest answer yet, and it complicates the one-size-fits-all advice that dominates wellness culture.
The study, published in BMC Medicine, drew on 1,940 participants from the Korean Genome and Epidemiology Study and mapped their adherence to the American Heart Association's Life's Essential 8 — diet, sleep, physical activity, nicotine avoidance, BMI, blood lipids, blood glucose, and blood pressure — against five separate epigenetic-age measures, including the widely cited GrimAge2 and the DunedinPACE pace-of-aging metric. The researchers then used a statistical method called quantile-based g-computation to tease apart how much each individual pillar contributed to slower biological aging, rather than treating the eight as an undifferentiated bundle. The headline finding is unsurprising in direction but useful in precision: better cardiovascular health was associated with lower epigenetic age acceleration across every clock tested, with collective effect estimates ranging from roughly −4.29 to −0.79 years depending on which clock you trust (Lee et al., BMC Medicine, 2025).
What is genuinely new — and what makes this paper worth a longevity reader's time — is the ranking. Not every pillar pulled equal weight, and the leaderboard changed depending on the participant's sex.
A sex-specific leaderboard
In male participants, the components contributing most to slower epigenetic aging were nicotine avoidance and better glucose control. That should not be read as a license to ignore the others — the Korean team explicitly frames Life's Essential 8 as a system of interacting factors — but it does suggest that for men in this cohort, the metabolic and tobacco-exposure pillars carried disproportionate weight in the multivariate decomposition (Lee et al., 2025).
The female ranking diverged. The authors note that the dominant contributors among women differed from men's, reinforcing a point that longevity medicine has been slow to internalize: the levers that move biological-age biomarkers are not uniformly distributed across populations. A protocol optimized around a 45-year-old male executive's risk profile may underweight the very factors most predictive for his sister.
Glucose regulation emerged as a top contributor to slower epigenetic aging in male participants — a finding consistent with the field's growing interest in metabolic flexibility as a longevity lever.
The levers that move biological-age biomarkers are not uniformly distributed across populations.
Why the clocks disagree — and why that matters
One subtlety worth dwelling on: the study measured five different epigenetic clocks, and they did not move in lockstep. Horvath's intrinsic clock, Hannum's extrinsic clock, PhenoAge, GrimAge2, and DunedinPACE each capture slightly different biology — some weight immune-cell composition, others weight mortality-associated proteins, others measure the rate at which aging is currently proceeding rather than how much has accumulated. The collective association between cardiovascular health and epigenetic age acceleration ranged across these clocks from about a fifth of a year to more than four years (Lee et al., 2025).
For readers tracking their own methylation panels, that spread is the story. A test that reports your GrimAge2 acceleration is not interchangeable with one that reports a Horvath number, and an intervention that meaningfully shifts one may barely touch another. The Korean data is a reminder to interpret a single biological-age readout with humility — and to be skeptical of any consumer service claiming a definitive number.
What this is, and what it isn't
The evidence here is moderate, not definitive. This is a cross-sectional analysis: it captures a snapshot in time and cannot prove that improving glucose control or quitting nicotine causes the epigenetic clock to slow. The cohort is Asian and Korean-specific, which is precisely why the authors undertook it — Asian cohorts have been underrepresented in epigenetic-aging research — but it also means the relative weightings may not transfer cleanly to other populations. And quantile-based g-computation, while a thoughtful tool for decomposing joint exposures, depends on modeling assumptions that thoughtful epidemiologists will debate.
What the paper does deliver is a credible, prospectively-collected, mechanism-agnostic ranking that lets a longevity-literate reader ask sharper questions of their clinician. If you are already meeting most of Life's Essential 8 targets, where is the marginal return on further effort? For men in this cohort, the data points toward metabolic and tobacco-exposure pillars. For women, the picture differs, and clinicians should be reading the supplementary tables rather than the abstract.
Diet is one of eight pillars in Life's Essential 8 — but its individual contribution to slower epigenetic aging was modest compared with metabolic and behavioral factors in male participants.
- Better cardiovascular health tracks with slower epigenetic aging across five different DNA-methylation clocks in a Korean cohort.
- The top contributors differ by sex. In men, nicotine avoidance and glucose control led the rankings; in women, a different set of pillars dominated.
- Not all clocks agree. Effect sizes ranged widely (≈ −0.79 to −4.29) depending on which epigenetic measure was used — single biological-age scores deserve skepticism.
- This is associational, not causal. A cross-sectional Asian cohort cannot prove that changing a pillar will move your clock.
- The Life's Essential 8 framework still holds as a coherent target — the new data refines, not replaces, it.
- Talk to a clinician before reweighting your own regimen based on a population-level ranking.
The broader arc here is encouraging. Five years ago, the standard advice for slowing biological aging amounted to a vague invocation of "healthy living." Today, researchers are quantifying which components of that bundle do the heaviest lifting, in which populations, against which biomarkers. The Korean analysis is one data point in a rapidly maturing literature — moderate evidence, carefully reported, and refreshingly honest about its own boundaries (Lee et al., 2025). For readers who have spent years optimizing every pillar at once, it offers something more valuable than another protocol: a reason to ask which pillar, for you specifically, deserves the next hour of your attention.