A new advisory recommending increased fish consumption for pregnant women could increase mercury poisoning in newborns, according to physicians and consumer groups. In comments to a federal risk communication meeting, the groups point out that recommendation to simply "eat more fish" is oversimplified and unlikely to achieve the intended benefits because methylmercury and omega-3 concentrations vary widely between fish species.
"It is important that people, especially pregnant women, increase their consumption of fish to two or three times per week in order to receive health benefits, but we urge caution on which fish to eat," said Mark Mitchell, MD, Co-Chair of the National Medical Association's Commission on Environmental Health. "For example, following FDA's advice about tuna consumption will result in increased maternal exposure to methylmercury, putting babies at risk."
Issued in June by U.S. Food and Drug Administration and Environmental Protection Agency, the proposed advisory recommends that pregnant women eat at least 8 ounces and up to 12 ounces per week of various lower-mercury fish in order to gain health benefits. The agencies' previous guidelines, issued in 2004, did not set a floor for seafood consumption.
"This advisory completely ignores more than a dozen scientific studies since 2004 that suggest that methylmercury is more damaging than previously documented," according to Michael Bender, director of Mercury Policy Project, a non-profit consumer advocacy organization. "These studies show that a pregnant woman's exposure to methylmercury in amounts similar to the typical levels in American consumers can harm her fetus."
"Low income people are more likely to eat canned tuna, since it is widely available, does not require refrigeration or cooking, and is free to some women on the WIC program," according to Fred Tutman, Patuxent Riverkeeper. "Given that tuna is higher in mercury than most other fish and therefore more dangerous to eat, it makes sense for pregnant women and young children to limit consumption of tuna," he said.
A survey of convenience stores in a low income neighborhood in Hartford show that low mercury fish are readily available to low-income people at similar or lower costs compared to that of tuna. "Canned salmon, sardines, and mackerel have higher beneficial omega-3 fatty acids, much lower mercury levels, and are often less expensive than tuna," said Dr. Mitchell. "There is no reason to risk children's health by recommending regular consumption of tuna," he said.