Dietary Guidelines Spark Flap Over Fish Consumption

Abstract

NUTRITION Recommendations from a nonprofit group urging pregnant women to boost their fish consumption—contrary to U.S. guidelines—sparked widespread criticism earlier this month, in part because the review was funded by the fisheries industry. The advisory from the National Healthy Mothers, Healthy Babies (HMHB) Coalition has been dismissed by health advocates and government officials alike. Yet some researchers not involved in the furor say that industry sponsorship should not obscure the fact that fish consumption has plummeted because of federal guidelines—and that standards should be reconsidered. In a statement issued on 4 October, HMHB and 14 researchers who reviewed the literature advised pregnant women to eat at least 12 ounces of fish each week to provide the developing fetus with brain-building omega-3 fatty acids. That contrasts with the position of the U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA), which in 2004 recommended that pregnant women consume no more than 12 ounces a week to limit their intake of mercury. ![Figure][1] Caveat consumptor. A diet of fish during pregnancy can both help and harm a fetus's developing brain. CREDIT: DPA/LANDOV Government agencies reacted swiftly to HMHB's pronouncement. Three of HMHB's members—the National Institute of Child Health and Human Development, the Centers for Disease Control and Prevention, and the Health Resources and Services Administration—rejected the advice in a letter in The Washington Post. FDA and EPA announced that their guidelines wouldn't be changing. Critics fault HMHB for accepting $60,000 from the National Fisheries Institute, an industry group, to disseminate the recommendations, along with honoraria of $1000 to $1500 per researcher. HMHB Executive Director Judy Meehan says the group gave no thought to how the industry funding would be perceived. “People seem to have strong opinions” about fish consumption, but the science is “open to lots of interpretation,” says Gary Myers, a pediatric neurologist at the University of Rochester in New York who has helped lead a major study of fish consumption in pregnancy, in the Seychelles northeast of Madagascar. He and others say it's difficult to identify the tipping point at which the risks of mercury in fish outweigh the benefits of omega-3 fatty acids. The topic also pits scientific disciplines against each other. “Environmental health people see the effects of mercury on the brain and get scared; nutrition people says there's this great nutrient and people aren't getting enough,” says Emily Oken, a nutrition researcher at Harvard Medical School in Boston who focuses on women's health. In her own study of 135 babies and their mothers, Oken found that higher fish consumption boosts cognition at 6 months of age, whereas mercury levels, measured in a mother's hair, decrease it. But on balance, she wrote in a 2005 paper in Environmental Health Perspectives , more fish in the diet was still associated with better cognition. In general, scientists note that both the benefits and drawbacks of fish are small for individuals, although they can be significant across a population. Exposure is usually measured as mercury in maternal hair. Some studies show that an increase in this index is linked to very subtle cognitive changes, including reduced word recall and a 1-point loss in IQ. HMHB's guidance gave little weight to the risks of mercury and did not recommend that pregnant women avoid high-mercury fish. Even some who worry that pregnant women consume too little fish say that HMHB's guidelines focus too much on the benefits of fish, just as the federal recommendations are faulted for overemphasizing the risks. In response, Patricia Nolan, a public health physician at Brown University who helped craft the HMHB recommendations, said in an e-mail that “we emphasized the positive because women are decreasing or eliminating already low fish consumption.” But what's really needed, says David Bellinger, a neuropsychologist at Harvard Medical School, is a more nuanced review that would give pregnant women a fuller picture of how specific types and quantities of fish in the diet could affect their baby-to-be. [1]: pending:yes