Answer:Alice H. Lichtenstein, DSc, director of the Cardiovascular Nutrition Laboratory at Tufts Jean Mayer Human Nutrition Research Center on Aging, explains that fish is beneficial because its an excellent source of the omega-3 fatty acids EPA and DHA. (For more on the benefits of omega-3s-and why other dietary sources such as walnuts and flaxseeds arent an efficient way to get EPA/DHA-see the July Special Report.) Fish and fish oil raise LDL cholesterol only in some hypertriglyceridemic individuals-those with an unhealthy excess of triglycerides in the blood-who take two to four grams a day of fish oil. (Thats a lot of fish oil, by the way: A typical fish-oil supplement contains 300-500 milligrams of EPA/DHA, and manufacturers recommend one to three such capsules daily, for a total of no more than about one gram. A three-ounce serving of salmon, before cooking, contains a little less than a gram of total omega-3s.) Even in such cases, Lichtenstein explains, the persons decrease in triglycerides and increase in good HDL cholesterol offset any potential adverse effects from the small increase in LDL. For most people, anyway, this is not an issue, so go ahead and eat fish! The American Heart Association and the latest federal dietary guidelines both recommend eating fish-especially the fatty, cold-water varieties like salmon highest in omega-3s-at least twice a week.