Most health experts recommend only eating tuna a few times a week and only eating sharka
few times a month. Why would health experts have this view of eating these fish?
Answers
Explanation:
Fish is a very important part of a healthy diet. Fish and other seafood are the major sources of healthful long-chain omega-3 fats and are also rich in other nutrients such as vitamin D and selenium, high in protein, and low in saturated fat. There is strong evidence that eating fish or taking fish oil is good for the heart and blood vessels. An analysis of 20 studies involving hundreds of thousands of participants indicates that eating approximately one to two 3-ounce servings of fatty fish a week—salmon, herring, mackerel, anchovies, or sardines—reduces the risk of dying from heart disease by 36 percent. (1)
Eating fish fights heart disease in several ways. The omega-3 fats in fish protect the heart against the development of erratic and potentially deadly cardiac rhythm disturbances. They also lower blood pressure and heart rate, improve blood vessel function, and, at higher doses, lower triglycerides and may ease inflammation. The strong and consistent evidence for benefits is such that the Dietary Guidelines for Americans, the American Heart Association, and others suggest that everyone eat fish twice a week. (2, 3)
Unfortunately, fewer than one in five Americans heeds that advice. About one-third of Americans eat seafood once a week, while nearly half eat fish only occasionally or not at all. (4) Although some people may simply not like fish, the generally low consumption is likely also caused by other factors, including perceptions about cost, access to stores that sell fish, and uncertainty about how to prepare or cook fish. Still others may avoid seafood because they worry that they—or their children—will be harmed by mercury, pesticide residues, or other possible toxins that are in some types of fish.
Should you forgo fish because of the contaminants they might carry? It’s a controversial topic that is often fueled more by emotion than by fact. Here’s what’s known about the benefits and risks of eating fish and other seafood:
Known or likely benefits: In a comprehensive analysis of human studies, Harvard School of Public Health professors Dariush Mozaffarian and Eric Rimm calculated that eating about 2 grams per week of omega-3 fatty acids in fish, equal to about one or two servings of fatty fish a week, reduces the chances of dying from heart disease by more than one-third. (1) Both observational studies and controlled trials have also demonstrated that the omega-3 fats in fish are important for optimal development of a baby’s brain and nervous system, and that the children of women who consume lower amounts of fish or omega-3’s during pregnancy and breast-feeding have evidence of delayed brain development.
Possible benefits: Eating fish once or twice a week may also reduce the risk of stroke, depression, Alzheimer’s disease, and other chronic conditions. (11)
Possible risks: Numerous pollutants make their way into the foods we eat, from fruits and vegetables to eggs and meat. Fish are no exception. The contaminants of most concern today are mercury, polychlorinated biphenyls (PCBs), dioxins, and pesticide residues. Very high levels of mercury can damage nerves in adults and disrupt development of the brain and nervous system in a fetus or young child. The effect of the far lower levels of mercury currently found in fish are controversial. They have been linked to subtle changes in nervous system development and a possible increased risk of cardiovascular disease. The case for PCBs and dioxins isn’t so clear. A comprehensive report on the benefits and risks of eating fish compiled by the Institute of Medicine calls the risk of cancer from PCBs “overrated.” (5)