DNA methylation is the attachment of small chemical marks (methyl groups) to DNA. These marks do not change the “text” of the genes themselves, but switch them on and off. It is one of the main mechanisms of epigenetics.
With age the pattern of methylation changes in a regular way — so predictably that it has become possible to determine biological age from it. This is the basis of the epigenetic “clocks” (Horvath, PhenoAge, GrimAge).
Epigenetic clocks and aging
By analyzing methylation at hundreds of points on the DNA, the “clocks” estimate how much a body is biologically older or younger than its calendar age. Such clocks (especially the newer-generation GrimAge) predict the risk of age-related diseases and mortality well — sometimes more accurately than calendar age.
This makes methylation one of the most promising markers of aging. Our PhenoAge calculator uses a similar idea, but based on blood markers rather than methylation.
What affects methylation
The rate of epigenetic aging is not fixed. It is accelerated by smoking, obesity, physical inactivity, chronic stress and inflammation. It is slowed by regular physical activity and a healthy diet: in lifestyle studies (for example, diet + activity) it was possible to slow down the methylation clock.
It is important to understand: consumer epigenetic tests are still imperfect and poorly standardized — their results should be treated as a guide, not an exact diagnosis.
Assess your biological age
Epigenetic clocks measure biological age; assess yours from blood markers:
Frequently asked questions
What are epigenetic clocks?
These are tests that estimate a person's biological age from the pattern of DNA methylation at hundreds of points. Such “clocks” (Horvath, PhenoAge, GrimAge) predict the risk of age-related diseases and mortality, sometimes more accurately than calendar age.
Can epigenetic aging be slowed?
It seems partly yes. In lifestyle studies, a healthy diet and physical activity slowed the pace of the methylation clock. Aging is accelerated by smoking, obesity, physical inactivity and chronic stress. There are no magic drugs with a proven effect.
Should I buy a home epigenetic test?
For now their results should be treated with caution: consumer epigenetic tests are poorly standardized, and their accuracy and reproducibility are limited. They can be regarded as a guide and motivation, but not as an exact medical diagnosis.
Related terms
Sources
- Epigenetic Clock: DNA Methylation in Aging. NCBI/PMC
- DNA methylation GrimAge predicts lifespan and healthspan. NCBI/PMC
- DNA methylation biomarkers slowed by diet+activity (DAMA). NCBI/PMC