Have Some Fish but Hold the Mercury

Tempted by tuna, hungering for halibut - but worried about mercury? A recent story in The New York Times has sparked concerns about sushi, but federal health agencies say you can feast on fish safely by following a few simple tips.

The Times reported on Jan. 23 that lab tests found alarmingly high levels of mercury at sushi stores and restaurants in Manhattan. "No one should eat a meal of tuna with mercury levels like those found in the restaurant samples more than about once every three weeks," Dr. Michael Gochfeld, professor of environmental and occupational medicine at the Robert Wood Johnson Medical School, told the paper.

However, the Center for Consumer Freedom, which is supported by the food industry, said the story was riddled with inaccuracies and that the highest level of mercury found in the sushi was "less than one-seventh of the lowest mercury concentration associated with actual health risks in scientific studies."

Amid concerns and confusion about who should eat how much of what types of fish, it's a good time to review recommendations from federal health agencies.

The U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) emphasize that seafood is an important part of a good diet. After all, it's rich in beneficial omega-3 fats, low in saturated fat and packed with protein and other nutrients.

Nearly all seafood also contains traces of mercury, which is not a health risk for most people, the FDA and EPA state. However, the higher levels of this metal in some species of fish can harm the nervous system of unborn babies or young children, the agencies say. So in 2004 they issued a few guidelines for young children, nursing mothers and women who are or might be pregnant:

Do not eat swordfish, shark, king mackerel or tilefish. These large species have high levels of mercury.
Eat up to 12 ounces (about two servings) of a variety of low-mercury seafood per week. Examples include salmon, shrimp, clams, tilapia, catfish, pollock and canned light tuna. Or eat up to only 6 ounces a week of albacore ("white") tuna or tuna steak, which aren't as low in mercury as canned light tuna.
If no advisories warn against eating locally caught fish, it's OK to eat up to 6 ounces if you don't eat any other fish that week.
Follow these guidelines with young children but offer smaller portions.

The recommendations from the FDA and EPA have sparked a lot of follow-up. For example, Consumer Reports found that some canned light tuna had more mercury than albacore did. Environmental Defense Fund says that bluefin, yellowfin (ahi) and bigeye tuna should be eaten infrequently if ever because of their high mercury content.

On the other hand, some health groups are warning that the recommendations have led people, especially pregnant women, to eat too little fish. The National Healthy Mothers, Healthy Babies Coalition - which includes the U.S. Centers for Disease Control and Prevention, the American Academy of Pediatrics and the March of Dimes - held a news conference in October 2007 and advised pregnant women to stock up on seafood.

"There is scientific evidence that fish leads to better outcomes in babies," Dr. Ashley S. Roman, a member of the coalition and an assistant professor at New York University Medical Center, said at the news conference. "It leads to better brain development, improved cognitive and motor skills, and some evidence suggests that it might reduce the risk of premature delivery and postpartum depression. Studies have shown that if you eat 12 ounces or more fish per week, you are doing better for your baby than if you eat less than that amount or no fish at all."

And some recent research, including reviews from the Harvard School of Public Health and the Institute of Medicine, has agreed that the cardiac and other benefits of eating seafood outweigh the risks.

As for the FDA, it told The Times that it already had a study under way to review the recommendations it issued in 2004.

So for now you can savor some salmon. But go for grilled, broiled, canned or lightly sauteed. Amid the hubbub over mercury, better not start another controversy by breaking out that deep fryer.