Obese and overweight young children whose mothers took DHA—a fat found in fish oil—during pregnancy had lower average blood pressure than those whose mothers did not take the supplement during pregnancy, according to a study funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The findings suggest that mothers who take DHA during pregnancy may protect their children against the risk of elevated blood pressure that accompanies childhood obesity.
The study appears in JAMA Network Open and was led by Susan E. Carlson, Ph.D., at the University of Kansas Medical Center in Kansas City.
Docosahexaenoic acid (DHA) is one of three fatty acids used for energy and tissue growth. DHA is found primarily in fish and other seafood. It is important for the development of the fetal brain during late pregnancy.
Previous studies have linked DHA consumption to lower blood pressure in adults and children. A study from the Netherlands found that children exposed to higher levels of DHA during pregnancy had lower blood pressure at age 6 years, compared to a group exposed to lower DHA levels. Researchers initiated the Kansas University DHA Outcome Study to learn if prenatal DHA supplements might improve birth outcomes and cognitive development. They re-analyzed the study data to determine if prenatal DHA might also have an effect on children’s blood pressure.
Mothers of 89 children took 600mg of DHA each day during pregnancy, while mothers of 82 children took a placebo. Children were classified as overweight and obese if they were above the 85th percentile for children their age in body mass index, a measure of weight and height.
Compared to obese and overweight children whose mothers took DHA, obese and overweight children of mothers from the placebo group had an average systolic blood pressure reading (top number) that was 3.94 mmHg higher and an average diastolic blood pressure reading (bottom number) that was 4.97 mmHg higher. In the DHA group, there was no difference with either reading between obese and overweight children and normal weight children.
Women who take a DHA supplement during pregnancy may protect their children from the risk of elevated blood pressure associated with obesity.
The researchers will continue to analyze data collected in the study to determine if prenatal DHA increases cognitive development in children 2 to 6 years of age.
Kerling, EH, et al. Effect of prenatal docosahexaenoic acid supplementation on blood pressure in children with overweight condition or obesity: a secondary analysis of a randomized clinical trial. JAMA Network Open. 2019. doi:10.1001/jamanetworkopen.2019.0088.