Omega-3 and ageing are the subject of a striking finding: a single daily dose could slow our biological age. These essential fatty acids, known for heart health, now show measurable anti-ageing potential. What is the effective dose, and what exactly does the science say? Here are the data presented at the Singapore longevity course.
Omega-3 and ageing: what the DO-HEALTH trial reveals
The most robust advance comes from the DO-HEALTH trial (Bischoff-Ferrari, Nat Ageing 2025). This study followed 777 people aged around 75, active and in good health, for 3 years. Participants received vitamin D (2,000 IU/day), omega-3 (1 g/day) and/or a home exercise programme.
The result is notable. Omega-3 alone slowed ageing as measured by several epigenetic clocks: PhenoAge, GrimAge2 and DunedinPACE. In practice, this represents a biological age reduced by an average of 0.18 years compared with placebo after three years. Better still, the three combined interventions (vitamin D, omega-3 and exercise) had an additive effect on PhenoAge. Movement and nutrition therefore reinforce one another.
DHA, EPA and inflammation: why it works
Omega-3s, including the well-known DHA and EPA, are polyunsaturated fatty acids (PUFA) that the body cannot produce on its own. Their value in ageing lies largely in their action on chronic low-grade inflammation, or "inflammaging", a recognised driver of age-related decline.
By modulating inflammatory processes, omega-3s act on a terrain that favours many age-related conditions. This underlying action explains why their benefits are found both for the heart and for markers of biological age.
The question of dose according to your goals
The whole subtlety lies in the dose, which varies with the goal pursued. The data presented make it possible to distinguish several levels.
For a healthy person, a baseline of around 500 mg per day is mentioned. To slow biological ageing in older people, it is the 1 g/day dose that demonstrated its effect in DO-HEALTH. Finally, for a cardiovascular or blood-pressure benefit, the dose rises to around 2 g/day. The dose is therefore not universal: it depends on the target.
Omega-3, the heart and blood pressure
Cardiovascular benefits strengthen the case for these fatty acids. Among 3,826 people with cardiovascular disease, aged 65 to 80, an optimal dose of 2.12 g/day was associated with lower all-cause mortality (HR 0.77) and cardiovascular mortality (HR 0.63) over nearly eight years (Yan, Sci Rep 2025).
For blood pressure, a meta-analysis of 71 controlled trials involving nearly 5,000 people (Zhang, JAHA 2022) shows a dose-response effect. At 2 g/day, systolic pressure falls by 2.61 mmHg and diastolic by 1.64 mmHg; at 3 g/day, the effect on diastolic pressure is even more marked. This benefit is linear in people with hypertension, hyperlipidaemia or older age.
In practice: nutrition, movement and caution
What should we take away? Omega-3s are one of the few supplements whose effect on biological age rests on a solid human trial. The 1 g/day dose stands out for slowing ageing in older adults, while higher doses target the heart and blood pressure.
Even when well tolerated, omega-3s remain supplements whose use should be discussed with a healthcare professional, taking current treatments into account. No dosage should be self-prescribed as a medicine.
Above all, the DO-HEALTH trial delivers a central message for longevity: the effect is additive with exercise. Omega-3 and ageing are part of a global strategy in which nutrition, movement and prevention work together. A supplement supports the terrain; it never replaces it.
