Fahy · Aging cell 2019 · uncontrolled interventional trial · n=?

Reversal of epigenetic aging and immunosenescent trends in humans.

Level 4 - case-series / case-control

Uncontrolled interventional before-after trial (case series)

PubMed 31496122 · doi:10.1111/acel.13028 · record verified 2026-08-26

What was done

Investigators evaluated the effect of a 1-year interventional protocol intended to regenerate the thymus on human biological age and immunological parameters. Epigenetic age was assessed at baseline, during the 12-month treatment, and 6 months post-treatment using four DNA methylation clocks, including the GrimAge predictor.

What was found

After 1 year of treatment, participants showed a mean epigenetic age reduction of approximately 1.5 years compared to baseline, corresponding to a 2.5-year reduction relative to untreated chronological progression. Epigenetic age reversal accelerated from -1.6 years/year between months 0–9 to -6.5 years/year between months 9–12. GrimAge showed a 2-year reduction in epigenetic versus chronological age that persisted 6 months after treatment cessation. Protective immunological changes and improved disease risk indices were reported without specific numerical values.

Why it matters

This study provides early proof-of-concept evidence that epigenetic aging markers in humans may be actively reversed with an accessible interventional protocol.

Limits

The abstract omits sample size, participant demographics, and specific treatment components. The study lacks a randomized or concurrent control group, limiting causal conclusions.