Eating fish for two.

Abstract

This article is based on the British Nutrition Foundation's Annual Lecture, which focused on maternal fish consumption and the effects of methylmercury (MeHg) on fetal development, with respect to current guidance and policy on fish consumption during pregnancy. Fish makes a valuable contribution to nutrient intakes across the globe and is the primary protein source for many individuals, particularly those in the developing world. Populations with a high fish consumption, such as in the Republic of the Seychelles, have a greater exposure to MeHg, which is present in varying amounts in all fish. Methylmercury is a toxic pollutant, which is known to impair neurodevelopment. The dose of MeHg from fish consumption, however, needed to impair neurodevelopment is unknown. Current UK and US guidance on fish consumption during pregnancy tend to focus more on avoiding risks rather than highlighting the benefits which can be obtained from eating fish. Such recommendations have been mainly based on data arising from epidemiological studies in the Faroe Islands, where methylmercury exposure was largely from pilot whale consumption. Although small adverse effects on child development have been reported in data from the Faroe Islands, data from the on-going Seychelles Child Development Studies have shown no adverse effects of prenatal methlymercury exposure from high maternal fish consumption (9-12 meals containing fish per week) on developmental outcomes. Instead these data suggest that nutrients, including long chain polyunsaturated fatty acids (LC-PUFAs), provided by fish may offer a beneficial effect and attenuate or modify any effects of MeHg on developmental outcomes. Recent expert consultations have concluded that the health benefits of fish consumption outweigh the risks posed by MeHg exposure and have argued the need for improved education and guidance to highlight the importance of consuming nutrients, including LC-PUFAs, from fish for optimal child development and to encourage fish consumption during pregnancy.