Should I take an omega-3 supplement, or get it from food?

The question I received: "Juliana, we keep hearing that omega-3s are essential for health. Should I be taking a supplement? Or is it better to get them from food?"

Before you buy another bottle, ask yourself one question: when did you last eat a sardine?

Omega-3 fatty acids are among the most studied nutrients in the world, and the research is consistent — they play meaningful roles in cardiovascular health, brain function, vision, and the regulation of inflammatory processes (Calder, Nutrients, 2020; AHA, Circulation, 2021). What the research does not consistently show is that supplementation produces the same outcomes for generally healthy people as getting these fats from whole food. For most people without a specific medical indication, the better investment is dietary.

The reason comes down to what researchers call the food matrix effect: nutrients in whole foods do not act alone. A can of sardines delivers omega-3 alongside complete protein, vitamin D, vitamin B12, iodine, selenium, and calcium from the bones. These work together in ways an isolated supplement cannot replicate.

Not all omega-3 is equivalent. The two forms that directly perform the functions the research documents — reducing triglycerides, supporting neural function, producing anti-inflammatory signalling molecules — are EPA and DHA. Both are found pre-formed in fatty fish.

Plant foods — flaxseed, chia seeds, walnuts, hemp seeds — contain a different form called ALA. ALA is genuinely beneficial and these foods belong in a healthy diet. The limitation is that the body converts only a small fraction of ALA into EPA and DHA. For anyone relying entirely on plant sources of omega-3, that conversion rate does not replicate what two weekly servings of fatty fish provide.

Fatty fish dominate this list. Sardines and mackerel sit at the top — small fish, low on the food chain, accumulating far less mercury than large predatory species, and available in canned form without significant nutrient loss. Herring, salmon, and trout follow closely. Two servings per week of any of these covers the omega-3 targets that major cardiovascular guidelines converge on (AHA, 2021; ESC, 2021).

Sardines deserve more attention than they get. A single serving provides meaningful EPA and DHA alongside complete protein, calcium from the bones, vitamin D, B12, and selenium — in one affordable can. If there is a case for calling a food underrated, sardines make it.

Chronic low-grade inflammation sits behind many conditions my clients navigate most — uterine fibroids, endometriosis, PCOS, painful periods, and cardiovascular disease. Omega-3 fatty acids do not treat or cure any of these conditions. What they do is contribute to producing specialized pro-resolving mediators — molecules that help the body wind down inflammatory responses rather than letting them persist (Calder, Nutrients, 2023). Within an overall anti-inflammatory eating pattern rich in vegetables, legumes, fruits, whole grains, nuts, and seeds, regular omega-3-rich fish is one of the most evidence-supported dietary strategies for supporting a lower inflammatory baseline.

If you eat two or more servings of fatty fish per week, you are likely meeting your needs through food. A supplement makes sense in a narrower set of situations: you eat no fish at all; you follow a vegan diet and want a reliable EPA/DHA source beyond ALA conversion; you are pregnant and your healthcare provider has recommended it; or your physician has identified a specific clinical reason — elevated triglycerides, for example — that warrants a therapeutic dose.

Algae-based omega-3 supplements are a well-supported option for those avoiding fish. Fish obtain their EPA and DHA from algae to begin with — the nutrient is the same, the delivery route is different. One caution: high-dose omega-3 supplements can interact with certain medications. Always discuss dose with a healthcare professional before supplementing beyond standard amounts.