The phrase "biological age" is increasingly common in consumer health, but research uses several different biomarkers that are not interchangeable. One important family of measures is based on DNA methylation — chemical marks associated with ageing and health-related processes.
A 2026 study from the Chinese National Twin Registry asked whether a cardiovascular-health score called Life’s Essential 8 was associated with three epigenetic ageing measures. The twin design makes the result especially interesting because the researchers could also compare identical co-twins who differed in their health profiles.
Quick answer
Did better cardiovascular health make the twins biologically younger?
The study found that higher Life’s Essential 8 scores were associated with slower values on selected epigenetic ageing measures, including DamAA and DunedinPACE within identical-twin pairs. That is not the same as proving that healthier behaviour reverses ageing, makes DNA younger or slows every biological system.
Key takeaways
- The cross-sectional analysis included 1,030 twins from 515 pairs in the Chinese National Twin Registry.
- The sample included 367 monozygotic and 148 dizygotic twin pairs.
- A longitudinal subset included 294 twins from 147 pairs with baseline and follow-up measurements.
- Higher Life’s Essential 8 scores were associated with slower values on selected DNA-methylation ageing measures.
- Within-MZ analyses retained associations for DamAA and DunedinPACE, reducing genetic confounding but not proving a universal causal anti-ageing effect.
What Life’s Essential 8 actually measures
Life’s Essential 8 is a cardiovascular-health framework built from four health behaviours — diet, physical activity, nicotine exposure and sleep — and four health factors: body mass index, blood lipids, blood glucose and blood pressure.
In this study, researchers combined those components into an LE8 score and compared it with three DNA-methylation ageing measures: GrimAge acceleration, DamAge acceleration and DunedinPACE. Each clock captures a different aspect of epigenetic ageing, so results should not be generalized from one measure to every concept of ageing.
Why the twin design strengthens the question
The study included 515 complete twin pairs, of whom 367 were monozygotic. Across all twins, higher LE8 scores were associated with lower or slower values on several epigenetic ageing measures after adjustment for age, sex, region, education, chronic disease history and alcohol use.
The researchers then compared differences within monozygotic pairs. Because identical twins share essentially the same inherited DNA and are matched for age and sex, within-pair differences reduce some genetic and family-background confounding. Associations with DamAA and DunedinPACE remained statistically significant in these within-MZ models.
The longitudinal subset adds time — but not a randomized experiment
A smaller subset of 294 twins had measurements at two time points. Cross-lagged models found temporal associations between baseline LE8 or health-factor scores and later DunedinPACE, while baseline health-behaviour scores were associated with later GrimAA.
Temporal ordering is useful, but the study was still observational. People were not randomly assigned to different LE8 profiles, and changes in an epigenetic clock are not automatically equivalent to changes in disease risk, function or lifespan.
Why “reversing ageing” would be the wrong headline
Epigenetic clocks are statistical biomarkers built from patterns of DNA methylation. They can be associated with ageing-related outcomes, but each clock has its own construction and interpretation. A lower value on one clock does not mean every organ or tissue has become younger.
The study supports an association between better cardiovascular-health profiles and selected epigenetic ageing measures. It does not establish that improving one LE8 component will reverse ageing, nor does it provide a consumer protocol for changing epigenetic age.
TwinPare perspective: track behaviours, not a promise of “younger DNA”
For TwinPare, the practical value lies in the structure of the evidence: sleep, activity, nicotine exposure and several cardiovascular risk factors form a connected health picture, while individual responses can still differ even within genetically similar pairs.
TwinPare Health & Fitness can support voluntary tracking of everyday health behaviours and trends. It does not currently measure DNA methylation, calculate epigenetic clocks or claim to determine biological age.
Source notes
The source has been verified and editorially reviewed for this article. The limitations below show which level of conclusion the sources support.
- [cao-2026-le8-epigenetic-ageing] Association between cardiovascular health and epigenetic aging: a twin study Hui Cao et al.. Clinical Epigenetics, 2026. Evidence type: Chinese National Twin Registry study of 1,030 twins with within-MZ analyses and a 294-person longitudinal subset Limitation: Higher Life’s Essential 8 scores were associated with slower values on selected DNA-methylation ageing measures, including DamAA and DunedinPACE within MZ pairs. These biomarker associations do not show that a person can reverse whole-body ageing or make DNA younger. PubMed PMC DOI
Editorial source review
This section shows how the article's key factual claims are linked to the source.
Phrasings that require caution
- Do not say the study proved that healthy habits reverse ageing or make DNA younger.
- Do not equate DamAA, GrimAA or DunedinPACE with a person’s total biological age.
- Within-MZ associations reduce genetic confounding but do not automatically establish causality.
- Do not imply that TwinPare measures DNA methylation or epigenetic ageing.
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