The benefits of fish intake: Results concerning prenatal mercury exposure and child outcomes from the ALSPAC prebirth cohort

Health advice to pregnant women concerning consumption of mercury-containing foods has resulted in anxiety, with subsequent avoidance of fish consumption during pregnancy. However, seafood contains many nutrients crucial for children's growth and development. Longitudinal studies in the Seychelles, where fish is a major component of the diet, have not demonstrated harmful cognitive effects in children with increasing maternal mercury levels. Is the same true in a more developed country (the UK) where fish is eaten less frequently? We review publications using data collected by the Avon Longitudinal Study of Parents and Children (ALSPAC) to address this topic. Total mercury levels were measured in maternal whole blood and umbilical cord tissue. Offspring were followed throughout childhood, especially their cognitive development. No adverse associations were noted. Significantly beneficial associations with prenatal mercury levels were shown for total and performance IQ, mathematical/scientific reasoning, and birthweight in fish-consuming vs non-fish consuming mothers. These beneficial findings are similar to those observed in the Seychelles where fish consumption is high and prenatal Hg levels are x10 higher than US levels. Government recommendations should be reviewed to emphasise the beneficial value of fish consumption during pregnancy. Data availability: ALSPAC data access is through a system of managed open access. The steps below highlight how to apply for access to the data included in this paper and all other ALSPAC data.1. Please read the ALSPAC access policy (http://www.bristol.ac.uk/media-library/sites/alspac/documents/researchers/data-access/ALSPAC_Access_Policy.pdf) which describes the process of accessing the data and biological samples in detail, and outlines the costs associated with doing so.2. You may also find it useful to browse our fully searchable research proposals database (https:// proposals.epi.bristol.ac.uk/), which lists all research projects that have been approved since April 2011.3. Please submit your research proposal (https://proposals.epi.bristol.ac.uk/) for consideration by the ALSPAC Executive Committee using the online process. You will receive a response within 10 working days to advise you whether your proposal has been approved. If you have any questions about accessing data, please email: alspac-data@bristol.ac.uk.