According to a new study conducted by the University of Bristol, a woman’s mercury levels during pregnancy are unlikely to have a negative effect on child development provided the mother eats fish. the study of 1990s children in the UK, with similar detailed studies in the Seychelles, is published in Neurotoxicology.
Importantly, the researchers also found that the types of fish consumed did not appear to matter, as the essential nutrients in the fish could protect against the mercury content of the fish. The most important factor was whether the woman ate fish or not. This contrasts with current advice warning pregnant women not to eat certain types of fish which have relatively high levels of mercury.
Although several studies have addressed this issue, this research focused on two contrasting studies of populations with mercury levels measured during pregnancy where children were monitored at frequent intervals during childhood.
The first is a study centered on a population of the Seychelles, where almost all pregnant women are fish eaters. The second study looked at analyzes of data from the University of Bristol 1990s Children’s Study (also known as the Avon Longitudinal Study of Parents and Children (ALSPAC)), based on a relatively industrialized area of South West England where fish is eaten far less frequently. No summary of the results of this study has been previously published.
Although it has been known for some time that children of women who eat fish during pregnancy are likely to benefit in various ways in terms of their eyesight and intellectual abilities, official advice has included the warning not to not eat certain types of fish that have relatively high levels of mercury. As a result, some women may stop eating fish “to be on the safe side”.
Dr Caroline Taylor, lead researcher and co-author of the study, said: “We found that maternal mercury levels during pregnancy are unlikely to have any adverse effects on child development provided that the mother eats fish.If she made him not eat fish, then there was evidence that his mercury level could have a harmful effect on the child.This could be due to the benefits of the mixture of essential nutrients that fish provides, including long chain fatty acids, iodine, vitamin D and selenium.”
Professor Jean Golding, co-author and Emeritus Professor of Pediatric and Perinatal Epidemiology at the University of Bristol, said: ‘It is important that opinions from health professionals revise their advice against the consumption of certain species of fish . these fish, but there is evidence from different countries that such advice can be confusing for pregnant women. at least two servings of fish per week, one of which must be fatty” – and omit all warnings that certain fish should not be eaten.”
The current study is funded through core support for ALSPAC by the UK Medical Research Council and the UK Wellcome Trust.