The Study
Individual and additive effects of vitamin D, omega-3 and exercise on DNA methylation clocks of biological aging in older adults from the DO-HEALTH trial
This study found that taking omega-3 supplements might slightly slow down how fast your body ages at the DNA level, especially when combined with vitamin D and exercise. But it doesn't prove these things make you live longer — just that they might change a few DNA signals that scientists use as clues.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave older people fish oil, vitamin D pills, or simple home exercises for 3 years to see if they could slow how fast their bodies age inside.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 567 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Slowing aging by 3–4 months over 3 years is like turning back your body’s clock by about 10% — a small but meaningful benefit for older adults.
- 2Fish oil (1g/day) slowed aging by about 3 months over 3 years.
- 3Vitamin D and exercise alone did nothing.
- 4All three together slowed aging by up to 3.8 months.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nature Aging
Year
2025
Authors
Heike A. Bischoff-Ferrari, S. Gängler, Maud Wieczorek, D. Belsky, Joanne Ryan, R. Kressig, H. B. Stähelin, Robert Theiler, B. Dawson-Hughes, René Rizzoli, Bruno Vellas, L. Rouch, S. Guyonnet, A. Egli, E. Orav, Walter C. Willett, S. Horvath
Related Content
Claims (6)
Taking a daily omega-3 supplement for three years might help slow down how fast your body ages at the cellular level, making you biologically younger by a few months compared to people who don’t take it.
Taking omega-3 supplements for three years may help lower certain biological markers in the blood that are tied to aging and death risk, like those related to inflammation and tissue repair, by a small but measurable amount.
If you're older and your vitamin D is high but your omega-3 levels are low, taking omega-3 supplements might slow down aging more than if your levels were already good. Your body’s starting nutrition seems to affect how well omega-3 works.
Taking omega-3 supplements, vitamin D pills, and doing light exercise at home three times a week for three years might slow down how fast your body ages—by about 3.8 months—compared to not doing any of these things.
Taking a daily omega-3 supplement might help your body age more slowly, making you biologically 3 to 4 months younger after three years compared to not taking it.
Taking vitamin D pills and doing light exercise at home three times a week for three years doesn't seem to slow down or speed up how fast your body ages at the molecular level, based on four different aging tests.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.