Omega-3 supplements, both when taken alone or combined with a protocol of vitamin D and exercise, were associated with a slowdown in four biological age tests which rely on DNA methylation in new analysis of the DO-HEALTH clinical trial published in Nature Aging. The research was conducted at the University of Zurich in Switzerland.

In the study, 777 participants took 2,000 IU vitamin D per day, and/or omega-3 (1 g per day), and/or a home exercise program for three years. Over the treatment period, the participants were evaluated for four novel DNA methylation measures of biological aging (PhenoAge, GrimAge, GrimAge2, and DunedinPACE).

Omega-3 alone slowed the DNAm clocks PhenoAge, GrimAge2, and DunedinPACE, while all three treatments had additive benefits on PhenoAge.

While vitamin D treatment alone didn’t significantly impact biological age tests, the combination of vitamin D and exercise showed a moderate epigenetic clock slowdown.

“Overall, from baseline to year three, standardized effects ranged from 0.16 to 0.32 units (2.9-3.8 months). In summary, our trial indicates a small protective effect of omega-3 treatment on slowing biological aging over three years across several clocks, with an additive protective effect of omega-3, vitamin D, and exercise based on PhenoAge,” the authors of the study wrote.

Many DNA methylation clocks have been correlated with age-related morbidity and mortality in previous studies, the authors noted. While small clinical studies have found associations between each of the interventions and changes in epigenetic clock measures, DO-HEALTH represents the first larger clinical study to evaluate such interactions, they said.