Eat fatty fish two to three times per week

Fatty fish (salmon, mackerel, sardines, herring) delivers EPA and DHA in the form the body uses most readily.

Why it works

EPA and DHA from fatty fish are absorbed more efficiently than from plant-based omega-3 sources. They are incorporated into neuronal cell membranes, improving membrane fluidity and receptor function. The epidemiological data linking fish intake to lower depression rates is among the most replicated in nutritional psychiatry. Whole-food sources also provide co-nutrients (selenium, iodine, vitamin D) that support the same neurological pathways.

How to do it

1. Aim for fatty fish at least twice a week — sardines and mackerel are high in EPA/DHA and low in mercury.
2. Wild-caught salmon, herring, and anchovies are good practical choices at moderate cost.
3. Canned sardines in water or olive oil are the most cost-effective high-EPA option.
4. Limit large predatory fish (tuna, swordfish) to reduce mercury exposure.

Evidence

Cross-national and cohort studies show inverse associations between fish consumption and depression rates. Hibbeln’s cross-national analysis is one of the foundational references. (observational)

Observational; confounders (diet quality, lifestyle) are plausible. Controlled trials on diet-sourced omega-3 and mood are limited.

Sources

• Hibbeln (1998), Fish consumption and major depression, The Lancet

Common mistake

Relying only on omega-3-"enriched" products (eggs, milk, spreads) as a substitute for actual fatty fish — the omega-3 amounts are much lower and often ALA, which poorly converts to EPA/DHA.