Benefits and concerns from eating fish
By Zhanglin Kong
Master of Nutrition Science, Registered Dietitian. Nutritionist of Greater Boston Chinese Golden Age Center
Fish is an excellent source of high quality protein and healthy fat, especially omega-3, and it is packed with healthful vitamins and minerals. Not many people know that fatty fish is a great source of Vitamin D, which is uncommon in other food. There is strong evidence that eating fish or taking fish oil is good for the heart and blood vessels, and research studies show eating approximately one to two 3-ounceservings of fatty fish a week reduces the risk of dying from heart disease by 36 percent. Fatty fish we commonly see include salmon, herring, mackerel, anchovies and sardines.
There is a great deal of scientific research studying the association between omega-3 polyunsaturated fatty acids and cognitive development throughout childhood. They show promising but inconclusive evidence. Some studies show that beneficial health outcomes are more likely to result from supplementation with DHA itself, which is why many baby formulas include DHA today. The effect of fish oil supplement on child intelligence remains uncertain. In spite of the uncertain cognitive benefit, fish itself should be included as a part of a nutritious meal for children.
One concern about eating fish is the mercury, since nearly all fish and shellfish contain traces of it.
The risk of eating large amount of mercury from fish and shellfish is that it may harm an unborn baby or young child’s developing nervous system. Therefore, the Food and Drug Administration and the Environmental Protection Agency advise women who may become pregnant, pregnant women, nursing mothers and young children to follow these recommendations.
1. Do not eat shark, swordfish, king mackerel or tilefish because they contain high levels of mercury.
2. Eat up to 12 ounces (two average meals) a week of a variety of fish and shellfish that are lower in mercury.
• Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock and catfish.
• Another commonly eaten fish, albacore (“white”) tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.
3. Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don’t consume any other fish during that week.
Other sources of omega-3 fats include nuts and tree nuts. Nuts contain large amounts of omega-3 fat and no cholesterol, along with no mercury. There is moderate evidence that consumption of unsalted peanuts and tree nuts such as walnuts, almonds and pistachios, along with a nutritionally adequate diet and moderate calorie intake, has a favorable impact on cardiovascular disease risk factors, particularly serum lipid levels. There is lack of solid evidence that eating nuts make children smarter. However, if your children are not allergic to nuts, they are nutritious food that can be a great part of a well-balanced diet to make them healthier.
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