Q: Why is fish good for you? Because it replaces red meat?
A: Many fish, especially oily, darker-fleshed fish like salmon and herring, are rich in heart-healthy, polyunsaturated, omega-3 fatty acids, but healthful fats are not the only reason to eat fish. Dietary guidelines in the United States encourage adults to eat 8 ounces of a variety of fish and seafood each week — roughly two meals’ worth — because of the “total package of nutrients in fish,” which includes lean protein, vitamins A and D as well as B vitamins, and a host of minerals such as iron, iodine, selenium and zinc.
“Fish is very low in saturated fat and very low in cholesterol,” said Jennifer McDaniel, a spokeswoman for the Academy of Nutrition and Dietetics, and people who follow a Mediterranean style diet that incorporates seafood appear to be at lower risk for obesity, “but a lot of people don’t think about that and just focus on omega-3s.”
Fish can be a much leaner and lower-calorie source of protein than meat, she noted. A cooked 4-ounce portion of cod, for example, contains 26 grams of protein but only 1 gram of fat and 120 calories, compared with a grilled 4-ounce portion of lean T-bone steak, which has 28 grams of protein, 18 grams of fat and 278 calories.
Nutrient content varies depending on the type of fish: Shellfish is especially high in selenium, and saltwater fish is high in iodine, McDaniel said. The iron in seafood, known as heme iron, is more easily absorbed by the body than the iron from plant sources, and the small bones in sardines are a good source of calcium.
Numerous studies have found that people who eat fish regularly are less likely to die of a heart attack than those who don’t eat it or eat it less than once a month, and a 2006 Harvard review concluded that eating one to two servings of fish rich in omega-3s every week cut the risk of dying of a heart attack by one-third.