Consuming fish high in Omega-3 fatty acids, even if they are also high in mercury at least twice a week can help reduce the risk of heart failure, coronary heart disease, cardiac arrest and ischemic stroke, says a new scientific advisory from the American Heart Association.

The Association recommends eating two 3.5-ounce servings of non-fried fish, or about three-fourth cup of flaked fish every week. Emphasis should be placed on eating oily fish like salmon, mackerel, herring, lake trout, sardines or albacore tuna, which are all high in omega-3 fatty acids. "Scientific studies have 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 at the Harvard University's T.H. Chan School of Public Health in Boston, US.

Further, the advisory, published in the journal Circulation, laid emphasis on eating fish such as shark, swordfish, tilefish, king mackerel, bigeye tuna, marlin and orange roughy that are high in mercury. Even though mercury contamination has been linked with serious neurological problems in newborns, it does not have adverse effects on heart disease risk in adults, the advisory noted. Moreover, the benefits of eating fish substantially outweighed any risks associated with mercury contamination, especially if a variety of seafood is consumed, it said.

According to a study, published in the journal Molecular Nutrition and Food Research, adding fatty fish to our diet increases the size and lipid composition of high-density lipoprotein (HDL) particles, also known as good cholesterol, in people with impaired glucose metabolism. Another study, published in the Journal of Nutritional Biochemistry, showed that Omega-3 fatty acids are more beneficial than flaxseed and other oils for preventing cancer.