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FDA's Midnight Mischief Heightens Mercury Risk to Pregnant Women, Infants

FDA's Midnight Mischief Heightens Mercury Risk to Pregnant Women, Infants

Friday, December 12, 2008

Fish is loaded with valuable nutrients, including protein, iron, omega-3 fatty acids, which reduce harmful cholesterol, lower blood pressure and prevent blood clots, and selenium, a trace mineral that helps the body prevent cellular damage.

But some ocean-dwelling fish also contain high levels of mercury, a powerful neurotoxin that is especially dangerous to the fetus and infants

In March 2004, under pressure from Environmental Working Group and other scientists and advocates, the federal Food and Drug Administration and the Environmental Protection Agency issued a joint advisory warning that women and young children should eat no more than 12 ounces of all seafood a week and should restrict their consumption of albacore tuna to 6 ounces per week. The warning added that women and children should not eat any shark, swordfish, king mackerel and tilefish because of their high mercury levels.

Internal FDA and EPA documents just obtained by EWG show that officials of the FDA are secretly mounting an eleventh-hour drive to eliminate the 2004 warnings on mercury in fish, a move that would benefit the commercial fishing industry.

EWG has obtained a draft FDA report that claims that almost every child and about 85 percent of adults with heart disease would benefit from increased consumption of all fish, including high-mercury species. (FDA 2008) The FDA document argues that “the net effect on fetal neurodevelopment from eating commercial fish containing methylmercury…is not necessarily adverse and could in fact be beneficial....” (FDA 2008)

The document asserts that pregnant women should eat at least 12 ounces of fish per week, a complete reversal of the current guidance.

The FDA report has met with fierce opposition from EPA scientists, according to other internal documents obtained by EWG.

In a scathing memo dated December 5, Dr. Peter W. Preuss, director of the Office of Research and Development at EPA’s National Center for Environmental Assessment (NCEA) wrote that he and his colleagues had “very serious concerns about this document [the FDA report], which is scientifically flawed and inadequate in several aspects.”

“It is not a product that NCEA will endorse or approve as it does not reach the level of scientific rigor routinely demonstrated by EPA,” Preuss wrote. He warned against releasing the FDA document or basing any policy decisions on its scientific assessment.

Without more information, we cannot make an exhaustive evaluation of FDA’s analysis. Based on the documents we have seen, some gaps and flawed reasoning are obvious. For example, the FDA paper makes no distinction among various species of fish, ignoring many scientific studies showing that species vary widely in their accumulation of mercury. (Letter from EPA NCEA to EPA office of Water regarding FDA’s draft assessment, Dec. 5, 2008.)

FDA officials have tried before to mislead consumers about mercury in fish.

In 2001, EWG learned that FDA was on the verge of caving in to pressure from the tuna industry to keep tuna off the list of fish whose consumption should be limited. FDA officials argued that any warning about fish consumption would cause women to avoid eating fish altogether. EWG obtained transcripts of focus groups conducted by FDA that showed otherwise.

The fishing industry has campaigned aggressively to overturn the FDA/EPA fish consumption warning. In October 2007, a group called Healthy Mothers Health Babies disseminated a report that urged pregnant women and others to eat more tuna. The report was quickly discredited when it was revealed National Fisheries Institute, a fishing industry trade group had funded key aspects of it.

A Harvard Medical School team’s study published last May found that 3-year-olds whose mothers had high mercury levels in their bodies scored lower on intelligence tests than other children. The study found some benefits of fish to counteract mercury toxicity. Team leader Dr. Emily Oken of Harvard Medical School wrote that "If mercury contamination were not present, the cognitive benefits of fish intake would be greater." (Oken, Radesky 2008)

Biomonitoring studies show that as many as 1 in 6 pregnant American women have excessive mercury concentrations. (Mahaffey, Clickner 2004) The placenta transports mercury to the developing fetus, causing permanent damage to the developing brain and nervous system.

Women who ate more than 2 servings of fish a week, as the FDA report proposes, would have 7 times higher concentrations of mercury than women who avoided fish entirely. (Mahaffey, Clickner 2004). Advising pregnant women to raise their fish consumption would certainly increase the number of pregnancies at risk of mercury poisoning.

The FDA must be prevented from pulling off the midnight mischief it contemplates. To the contrary, the agency should redouble its efforts to encourage women to eat a balanced diet rich in low-mercury fish and other safe sources of omega-3 fatty acids, such as wild salmon, shrimp, fortified eggs, margarine and walnuts. Most studies on the benefits and hazards of fish consumption have concluded that low-mercury fish are the only advisable option. (Budtz-Jorgensen 2007; Choi 2008; Domingo 2007; Ginsberg 2000; Mahaffey 2004; Mahaffey K. R. 2008; Mahaffey K.R. 2008; Mozaffarian 2006; Oken and Bellinger 2008; Oken, Radesky 2008; Sakamoto 2004; Stern 2005; Tsuchiya 2008)

REFERENCES

Budtz-Jorgensen E, Grandjean P, Weihe P. 2007. Separation of risks and benefits of seafood intake. Environ Health Perspect 115(3): 323-7.

Choi AL, Cordier S, Weihe P, Grandjean P. 2008. Negative confounding in the evaluation of toxicity: the case of methylmercury in fish and seafood. Crit Rev Toxicol 38(10): 877-93.

Domingo JL, Bocio A, Falco G, Llobet JM. 2007. Benefits and risks of fish consumption Part I. A quantitative analysis of the intake of omega-3 fatty acids and chemical contaminants. Toxicology 230(2-3): 219-26.

FDA. 2008. Draft-An Evaluation of Risks to U.S. Consumers from Methylmercury in Commercial Fish Products, including a quantitative assessment of risk and beneficial health effects from fish. Washington, DC: Food and Drug Administration.

Ginsberg GL, Toal BF. 2000. Development of a single-meal fish consumption advisory for methyl mercury. Risk Anal 20(1): 41-7.

Mahaffey KR. 2004. Fish and shellfish as dietary sources of methylmercury and the omega-3 fatty acids, eicosahexaenoic acid and docosahexaenoic acid: risks and benefits. Environ Res 95(3): 414-28.

Mahaffey KR, Clickner RP, Bodurow CC. 2004. Blood organic mercury and dietary mercury intake: National Health and Nutrition Examination Survey, 1999 and 2000. Environ Health Perspect 112(5): 562-70.

Mahaffey KR, Clickner RP, Jeffries RA. 2008. Methylmercury and omega-3 fatty acids: co-occurrence of dietary sources with emphasis on fish and shellfish. Environ Res 107(1): 20-9.

Mahaffey KR, Clickner RP, Jeffries RA. 2008. Methylmercury and omega-3 fatty acids: co-occurrence of dietary sources with emphasis on fish and shellfish. Environ Res 107(1): 20-9.

Mozaffarian D, Rimm EB. 2006. Fish intake, contaminants, and human health: evaluating the risks and the benefits. Jama 296(15): 1885-99.

Oken E, Bellinger DC. 2008. Fish consumption, methylmercury and child neurodevelopment. Curr Opin Pediatr 20(2): 178-83.

Oken E, Radesky JS, Wright RO, Bellinger DC, Amarasiriwardena CJ, Kleinman KP, et al. 2008. Maternal Fish Intake during Pregnancy, Blood Mercury Levels, and Child Cognition at Age 3 Years in a US Cohort. Am J Epidemiol 167(10): 1171-81.

Sakamoto M, Kubota M, Liu XJ, Murata K, Nakai K, Satoh H. 2004. Maternal and fetal mercury and n-3 polyunsaturated fatty acids as a risk and benefit of fish consumption to fetus. Environ Sci Technol 38(14): 3860-3.

Stern AH. 2005. Balancing the risks and benefits of fish consumption. Ann Intern Med 142(11): 949.

Tsuchiya A, Hardy J, Burbacher TM, Faustman EM, Marien K. 2008. Fish intake guidelines: incorporating n-3 fatty acid intake and contaminant exposure in the Korean and Japanese communities. Am J Clin Nutr 87(6): 1867-75.

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