Cohen Joshua T, Bellinger David C, Shaywitz Bennett A
Harvard Center for Risk Analysis, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
Am J Prev Med. 2005 Nov;29(4):353-65. doi: 10.1016/j.amepre.2005.06.007.
Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish also contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard Center for Risk Analysis convened an expert panel (see acknowledgements) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper quantifies the impact of prenatal MeHg exposure on cognitive development. Other papers quantify the beneficial impact of prenatal intake of n-3 PUFAs on cognitive function and the extent to which fish consumption protects against coronary heart disease mortality and stroke in adults. This analysis aggregates results from three major prospective epidemiology studies to quantify the association between prenatal MeHg exposure and cognitive development as measured by intelligence quotient (IQ). It finds that prenatal MeHg exposure sufficient to increase the concentration of mercury in maternal hair at parturition by 1 microg/g decreases IQ by 0.7 points. This paper identifies important sources of uncertainty influencing this estimate, concluding that the plausible range of values for this loss is 0 to 1.5 IQ points.
尽管某些鱼类富含可能带来多种健康益处的n-3多不饱和脂肪酸（PUFA），但一些鱼类也含有甲基汞（MeHg），这可能会对发育中的胎儿造成伤害。美国政府针对育龄妇女的建议是调整高甲基汞鱼类的摄入量以减少甲基汞暴露，而对于普通人群，由于鱼类的营养益处，政府的建议是鼓励食用鱼类。哈佛风险分析中心召集了一个专家小组（见致谢部分），以量化由此导致的人群鱼类消费假设性变化的净影响。本文量化了产前甲基汞暴露对认知发育的影响。其他论文则量化了产前摄入n-3多不饱和脂肪酸对认知功能的有益影响，以及鱼类消费对成年人预防冠心病死亡和中风的保护程度。该分析汇总了三项主要前瞻性流行病学研究的结果，以量化产前甲基汞暴露与以智商（IQ）衡量的认知发育之间的关联。研究发现，产前甲基汞暴露足以使分娩时母体头发中的汞浓度每增加1微克/克，智商就会降低0.7分。本文确定了影响这一估计的重要不确定性来源，得出的结论是，这种损失的合理取值范围为0至1.5个智商点。
