In their previously released dietary and lifestyle recommendations, the American Heart Association (AHA) encouraged the consumption of fish twice a week. But concerns have risen over the contamination of fish which may contain traces of mercury, which can be toxic to human beings.
Now, in a new scientific advisory published in the AHA journal Circulation, nutrition experts reaffirmed the safety and the heart health benefits of eating fish.
"Since the last advisory on eating fish was issued by the Association in 2002, scientific studies have further established the beneficial effects of eating seafood rich in omega-3 fatty acids, especially when it replaces less healthy foods such as meats that are high in artery-clogging saturated fat," said Eric B. Rimm, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health in Boston.
The AHA recommended eating two 3.5-ounce servings of non-fried fish, or about three-quarters of a cup of flaked fish every week. Consumption of oily fish like salmon, mackerel, herring, lake trout, sardines or albacore tuna was encouraged. The consumption of omega-3 fatty acids was emphasized due to its association with the reduced risk of health problems including heart disease, arthritis, dementia, and certain mental health conditions.
Industrial activity is responsible for increasing levels of airborne mercury, which can eventually end up in natural water bodies. The mercury may then be consumed by marine animals, especially large fish such as shark, swordfish, tilefish, king mackerel, bigeye tuna, etc.
A panel of nutrition experts reviewed studies about mercury in fish and agreed that mercury contamination may be linked to neurological problems in newborns. This reflected the dietary recommendations for pregnant women which listed certain fish among foods to be avoided. But their review of existing scientific research stated that the benefits of fish consumption outweighed the risks of mercury contamination. They also found that it did not increase heart disease risk in adults especially if a variety of seafood was consumed.
In their previous advisory, the AHA did not recommend omega-3 fish oil supplements for the prevention of clinical cardiovascular disease. It was attributed to the lack of scientific evidence regarding the effects of supplements on cardiovascular risk. The new advisory also discussed other related topics such as the importance of sustainable fish farming techniques.
In 2017, the Food and Drug Administration (FDA) and the Environmental Protection Agency offered safety advice and recommended that adults consume 8 to 12 ounces of lower-mercury fish per week.
"Fish are an important source of protein and other nutrients for young children and women who are or may become pregnant or are breastfeeding. This advice clearly shows the great diversity of fish in the U.S. market that they can consume safely," said Dr. Stephen Ostroff, FDA Deputy Commissioner for Foods and Veterinary Medicine.