Studies say go ahead, eat that seafood

WASHINGTON – The health benefits of eating fish regularly outweigh the danger from mercury and other contaminants even for pregnant women and children, two major reports concluded Tuesday as scientists tried to resolve a slippery question that has long vexed consumers.

The findings, which were reached by independent teams of scientists, pointed to significant benefits for both young and old.

In adults, the death rate from heart disease was 36 percent lower among those who ate fish twice per week compared with those who ate little or no seafood, according to a study being published today in the Journal of the American Medical Association. Overall mortality was 17 percent lower, the study by Harvard School of Public Health researchers found.

A second, federally funded report released by the Institute of Medicine (IOM) echoed the conclusion that the heart benefits of eating seafood outweigh its risks, and said infants also benefit from the healthy fats found in seafood.

Fatty acids known as omega-3s promote healthy vision and brain development in infants whose mothers consume fish or seafood during pregnancy or while nursing, the report said. These healthy fats also appear to decrease the risk of delivering a pre-term, low birth-weight baby.

Even so, because of methyl mercury concerns, the IOM report stuck with the current federal guidelines that advise women who are nursing, pregnant or plan to become pregnant, as well as children ages 12 and younger, to skip eating swordfish, shark, tilefish and king mackerel. These two groups can safely consume up to 12 ounces of other fish per week, the report said, but they should also limit white (albacore) tuna to no more than six ounces a week because of its high levels of methyl mercury, which can be toxic to the brain and hearing.

The new findings are expected to help put to rest a nutritional debate that often left perplexed consumers asking, “What do I do about fish?”

“Having this report will be really good,” noted Walter Willet, professor of epidemiology and nutrition at the Harvard School of Public Health, who was not a co-author of either study.

While the new findings may help to settle the question of the risks of eating seafood, there is still disagreement about the extent of the health benefits. A study published earlier this year in the British Medical Journal found no overall reduction in mortality, no decrease in heart disease risk and no reduction in cancer from consuming omega-3 fatty acids.

“I feel quite comfortable with the evidence that seafood is good for you but am a little taken aback by the conclusion that the benefits are as sweeping as in the JAMA study,” Goldberg said.

Other recent studies have hinted that omega-3 fatty acids may also help protect against diabetes and cancer, slow the progression of early Alzheimer’s disease and perhaps ameliorate depression and other mental disorders, including attention deficit disorder in children. But the IOM report found that the evidence for those benefits is unclear, and the Harvard study did not address those questions.

Both reports found little evidence to fuel concerns that seafood consumption exposes people to large amounts of dioxins, polychlorinated biphenyls (PCBs) and other harmful organic chemicals that have been linked to eating seafood.

The findings of both reports are consistent with current recommendations of the U.S. Dietary Guidelines and the American Heart Association.