Just the other day a friend warned me that I shouldn’t consume too much tuna in a given week. I rarely eat tuna, but in an effort to consume the remaining food in my home, I was eating my third 5-ounce can in a seven day period. I was told that the mercury levels were too high and that eating tuna more than once a week was dangerous.
Obviously too much of anything is rarely a good thing, but is eating tuna fish more than once a week truly dangerous to my health?
Myth: Tuna shouldn't be eaten more than once a week.
It is true that nearly all fish contain traces of mercury, according to the FDA. But this is not necessarily a health concern for most healthy individuals. The American Heart Association recommends eating a 3.5-ounce serving of fatty fish – including albacore tuna – two times per week. Up to 12 ounces of canned light tuna (the "light" versions of Bumble Bee or StarKist tunas, for example) can be eaten per week without complications.
Myth: Eating fish is not good for your heart.
PETA's brochure on tuna states that "tuna flesh is loaded with heavy metals that attack the heart muscle, so the toxicity outweighs any possible health benefits of omega-3 fatty acids." Though hardly an objective source on such matters, PETA raises a concern that many consumers may also have.
Nevertheless, the American Heart Association recommends eating fatty fish two times per week and albacore tuna is among those fish identified as being high in omega-3 fatty acids, which are good for your heart. The AHA also says that consuming omega-3s through food is preferable to taking supplements--though there are exceptions to this rule, including those with coronary artery disease.
Myth: Eating tuna is enough to stay heart-healthy.
Though eating tuna is certainly good for you, the AHA does specify a number of other healthy foods in addition to tuna. Other heart-healthy foods include tofu, soybeans, canola, walnuts, flaxseed, as well as walnut and flaxseed oils.
Still, there are some risks in eating fish that consumers need to be aware of. Women who might become pregnant, nursing women, pregnant women and young children should avoid shark, swordfish, king mackerel and tilefish, as these contain high levels of mercury. High levels of mercury can affect the growth of the nervous system in developing individuals.
American Heart Association. (7 September 2010). "Fish and omega-3 fatty acids." American Heart Association. Retrieved from http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyDietGoals/Fish-and-Omega-3-Fatty-Acids_UCM_303248_Article.jsp.
American Heart Association. (20 January 2012). "Fish 101." American Heart Association. Retrieved from http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/Fish-101_UCM_305986_Article.jsp.
U.S. Food and Drug Administration. (March 2004). "What you need to know about mercury in fish and shellfish." Food Safety: Product-Specific Information. Retrieved from http://www.fda.gov/food/foodsafety/product-specificinformation/seafood/foodbornepathogenscontaminants/methylmercury/ucm115662.htm