Quantitative approaches to understanding the balance of risks and beneficial effects from fish consumption: New modeling approaches

Methylmercury is the neurotoxic organic form of mercury found in all fish and shellfish. The primary public health issue is whether methylmercury causes neurologic effects at current levels of exposure that are of sufficient magnitude to be of concern The FDA has issued a draft risk/ benefit assessment on the net effect of eating commercial fish and shellfish on (1) fetal neurodevelopment; (2) fatal coronary heart disease (CHD); and (3) fatal stroke. The net effect includes an adverse contribution from methylmercury and a beneficial contribution from fish. The assessment estimates an overall net beneficial effect on fetal neurodevelopment with the net effect being beneficial for about 99% of the population. It is neutral for about one percent and adverse for about one-tenth of one percent of the population. The probability of adverse effects appears to result from eating fish relatively high in methylmercury. Eating more than 12 ounces per week of low methylmercury fish is estimated to confer slightly greater benefits than eating less than 12 ounces per week. The risk and benefit assessment used data from many research studies, involving hundreds of thousands of study participants, that have measured associations between fish consumption and fatal CHD and fatal stroke. Although the results from different cohorts were not entirely consistent, the assessment indicates that the impact of fish consumption on cardiovascular disease is beneficial. The assessment estimates that current fish consumption is averting about 30,000 deaths per year from coronary heart disease and 20,000 deaths per year from fatal stroke.