Does eating fish during pregnancy improve a child’s intelligence? According to a recent study published in the American Journal of Clinical Nutrition the answer is yes. The study revealed that infants of mothers who consumed more fish during pregnancy achieved higher scores in verbal intelligence and fine motor skill testing, as well as having a higher pro-social behavior. The study is part of the NUTRIMENTHE project “Effect of diet on offspring’s cognitive development”, which focuses on the effects of genetic variants and maternal fish intake on the children’s intellectual capacity.

Fish oil is the primary source of Omega-3 fatty acids and contains docosahexaenoic acid (DHA), the main component of brain cell membranes. According to the European Commission, who validated and supports DHA’s beneficial effects, “it contributes to the normal development of the brain and eye of the fetus and breastfed infants”.

Professor Cristina Campoy Folgoso, and her team decided to evaluate the effects of pregnant women’s’ fish consumption in terms of Omega-3 and Omega-6 fatty acids on fetal development, as well as to determine the effects of different genotypes on long-chain fatty acid concentrations in the fetus. They focused mainly on polymorphisms in the fatty acid desaturase (FADS) gene cluster, which encodes the delta-5 and delta-6 desaturase enzymes involved in the synthesis of long-chain fatty acids of the omega-3 and omega-6 series.

The research team obtained two blood samples from 2,000 women, with the first sample taken when the women were 20 weeks pregnant, and the second sample obtained from the umbilical cord at birth. The blood samples were subsequently analyzed for concentrations of long-chain fatty acids of the omega-3 and omega-6 series, after which the team determined the genotype of 18 polymorphisms in the FADS gene cluster.

The affects of FADS gene cluster polymorphisms on long-chain polyunsaturated fatty acid concentrations in women during pregnancy has been established in a separate study by Dr. Pauline Emmett at the University of Bristol and Dr. Eva Lattka from the Helmholtz Zentrum München, the German Research Center for Environmental Health.

The researchers established that fatty acid concentrations in umbilical cord blood depend on maternal and offspring genotypes. Maternal genotypes are therefore mainly linked to omega-6 fatty acid precursors, whilst the genotypes of the infants’ are linked to the more highly elongated fatty acids of the omega-6 series. The findings also demonstrated that concentrations of docosahexaenoic acid (DHA) of the Omega-3 series depend on maternal and offspring genotypes.

Dr Lattka concludes that:

“the fetal contribution of long-chain polyunsaturated fatty acids of the omega-6 series is more relevant than expected; fetal DHA concentrations depend on maternal and fetal metabolism. The amount of DHA transmitted to the fetus through the placenta might be crucial for fetal development.”

The same research team established in an earlier study that consuming fish during pregnancy is linked to the IQ in 8-year old children, however there is little knowledge about what causes this effect. Although the study showed that consuming fish is associated with maternal blood DHA concentrations, it remains unclear whether maternal DHA concentrations are directly linked to the children’s IQ. The goal of the NUTRIMENTHE project, projected to conclude in 2013, is to provide an answer to this question.

Researchers involved in the NUTRIMENTHE project organized an international symposium held during the European Nutrition Conference in Madrid last October on “Nutrition and Cognitive Function” with participating researchers from Belgium, Germany, Hungary, Italy, Netherlands, Poland, UK, USA and Spain (Rovira i Virgili and Granada).

Written by Petra Rattue