Fish and omega-3s: food or fish oil capsules?
Nutrition
Key points
- 1 to 2 servings of fish a week are linked to lower risk of coronary death.
- For most people the benefits of fish outweigh mercury risks.
- Cochrane: omega-3 supplements have little or no effect on mortality and cardiovascular events.
- Pregnant women should choose low-mercury fish and avoid shark, swordfish, king mackerel and tilefish from the Gulf of Mexico.
Fish: what the data show
A review in JAMA by Mozaffarian and Rimm concluded that eating 1 to 2 servings of fish a week, especially fatty fish such as salmon, sardines or mackerel, was linked to a 36% lower risk of death from coronary heart disease. For most people, the benefits clearly outweighed the potential risks from mercury and other contaminants (Mozaffarian & Rimm, 2006).
Omega-3 supplements: less benefit than expected
A Cochrane review of 86 randomized trials with more than 162,000 participants found that increasing long-chain omega-3s, mainly through supplements, had little or no effect on all-cause mortality, cardiovascular events or stroke (Abdelhamid et al., 2020).
Bottom line
Fish as part of a balanced diet is a good choice. Over-the-counter fish oil capsules are not a substitute and are unlikely to protect your heart on their own. The EAT–Lancet Commission includes fish as a regular protein source (Willett et al., 2019).
How to eat more fish
- Canned salmon or sardines on whole-grain crackers or in a salad.
- Baked fish with vegetables once a week.
- Shrimp or fish tacos.
- Canned light tuna in a sandwich instead of deli meat.
Frequently asked questions
How much fish should I eat?
The Dietary Guidelines suggest at least 8 ounces of seafood a week for adults. The FDA advises pregnant and breastfeeding women to eat 8 to 12 ounces a week of low-mercury fish.
Which fish are lowest in mercury?
Salmon, sardines, anchovies, trout, shrimp, cod, pollock, tilapia and canned light tuna are among the FDA’s "best choices".
Sources
- Mozaffarian et al. (2006). Fish Intake, Contaminants, and Human Health. JAMA 296(15):1885. doi:10.1001/jama.296.15.1885
- Abdelhamid et al. (2020). Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2020(3). doi:10.1002/14651858.CD003177.pub5
- Willett et al. (2019). Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet 393(10170):447-492. doi:10.1016/S0140-6736(18)31788-4
- U.S. Food and Drug Administration. Advice about Eating Fish. www.fda.gov
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