Overview
- Researchers analyzed blood from 958 healthy U.S. participants (average age about 70) at baseline, 12 months and 24 months within the randomized COSMOS trial.
- Across two years, the supplement group showed roughly four months less biological ageing overall, with significant effects on PCGrimAge (about 1.4 months) and PCPhenoAge (about 2.6 months) among five clocks tested.
- The benefit was larger in participants showing accelerated biological ageing at the start, including roughly a 2.8‑month slowing on PCGrimAge in that subgroup.
- The cocoa‑extract intervention did not affect any of the five DNA methylation measures of ageing.
- Authors and outside experts describe the effect as modest and limited to surrogate biomarkers in a mostly White, healthy cohort; supplements were supplied and some funding provided by Haleon/Centrum and Mars, which did not design the study.