1. I'm worried about mercury contamination. Should I skip fish altogether?
Absolutely not. "You should be much more nervous about how you're risking your health if you don't
eat fish," says Dariush Mozaffarian, M.D., a cardiologist at the Harvard School of Public Health, who co-authored a recent study analyzing the pros and cons of fish consumption. "Seafood is a key source of heart-healthy lean protein — everyone should aim to have two servings per week." And if you choose varieties rich in omega-3 fatty acids, such as tuna or salmon, you can reduce your risk of death from a heart attack by 36 percent, according to Mozaffarian's research. These fatty acids also play a crucial role in infants' brain development and may help lessen depression in adults.
If you're pregnant, thinking about conceiving, or feeding young children, do make sure that your two weekly fish servings come from species that are low in mercury (see "The Best and Worst Seafood Choices," last page). Mercury accumulates throughout fish's bodies after it's been released into the environment by natural and industrial sources. "Too much mercury can lead to developmental delays or cognitive problems for kids and even cause memory loss, unexplainable fatigue, and cardiovascular disease for adults," says Rebecca Goldburg, Ph.D., a senior scientist for the Environmental Defense Fund's Health and Oceans programs.
The Food and Drug Administration recommends avoiding large, predatory fish such as shark, swordfish, king mackerel tilefish, which accumulate the highest mercury levels. Instead, stick to low-mercury species like anchovies, Atlantic mackerel, wild Alaskan salmon, catfish, freshwater rainbow trout, oysters, shrimp, pollack, sardines, and canned light tuna, which has a lower level than canned albacore ("white") tuna. These choices are also rich in omega-3s, so you'll reap all the health benefits with fewer risks.