Omega-3 Benefits of Fish Outweigh Mercury Concerns

UMEÅ, SwedenThe hazards of eating mercury-laden seafood has made headlines over the past few weeks; however, a new study published in the American Journal of Clinical Nutrition (AJCN) suggests the heart-health benefits from omega-3 fatty acids outweigh the risks of mercury content at low levels.

Researchers at Umeå University examined how the risk of heart attack is contingent on the amount of omega-3 fats and mercury from fish people have in their body. The content was measured in blood and hair samples from people who had previously participated in health studies in northern Sweden and eastern Finland. The Swedish blood samples were from the Medical Biobank in Umeå. Those who experienced a heart attack after the health check-up were compared with those who did not.

Mercury was linked to increased risk of having a heart attack, while omega-3 fatty acids were linked to a decreased risk. The increased risk from mercury was noticeable only at high levels of the environmental pollutant in the body and if the level of the protective omega-3 fatty acids was concomitantly low. In other words, what is important is the balance between healthful and hazardous substances in fish.

The researchers advised people eat fish, but avoid fish with the most pollutants. The Swedish National Food Agency recommends that people should eat fish two to three times a week, but their intake of predatory fish, such as pike, perch, pike-perch, which contain a great deal of mercury, should be limited.

The study supports previous research at the university that found the health benefits from omega-3 fatty acids override any harmful effect of mercury. A 2012 study conducted by researchers at the Nutrition & Obesity Unit of Hospital Ramón y Cajal in Madrid found frequent consumption of white fish, such as hake, improves blood pressure, lowers cholesterol and reduces weight.