SATURDAY, Feb. 19, 2005 (HealthDayNews) -- Adding fish to your diet can help get you in the swim of things when it comes to better cardiovascular health, but experts at the Mayo Clinic also warn there are some contaminants -- most notably mercury -- to watch out for in fish, as well.
Fish is lower in saturated fat, total fat and calories than comparable portions of meat or poultry, the experts note in the February issue of the Mayo Clinic Women's HealthSource. Some species of fish -- such as fatty, coldwater fish including salmon, mackerel and herring -- are high in omega-3 fatty acids. This type of healthy fat, also found in anchovies, sardines and lake trout, appears to help prevent blood clots that can cause heart attacks.
However, fish can also contain toxins such as mercury and other pollutants. For most people, the amount of mercury ingested by eating fish isn't a health concern. But even small amounts of mercury may prove dangerous to developing fetuses, babies and young children, the Mayo authors conclude.
Children under age 5, nursing mothers and women who are pregnant or trying to conceive should avoid fish with the highest mercury levels -- tile fish, swordfish, king mackerel and shark. They should also limit their fish intake to no more than 12 ounces a week of fish and shellfish that contain low levels of mercury, foods such as shrimp, salmon, pollock, canned light tuna and catfish.
Albacore tuna is higher in mercury than canned light tuna, so consumption of albacore tuna should be limited to nor more than six ounces a week, the experts write.
Eating a variety of fish may reduce the potential negative effects of environmental pollutants. Try to avoid farm-raised fish, which tend to have more fat and calories and slightly less protein than wild fish. Farm-fed fish may also contain higher levels of contaminants due to toxins in their feed, according to the experts.
The U.S. Center for Food Safety and Applied Nutrition has more about mercury in fish and shellfish.