PREGNANCY

New Research – DHA Omega-3 During Pregnancy and a Child’s Weight 5 Years Later

By: Nate Matusheski, PhD

October 29, 2018

If you are an expecting mother, or if you already have children, you may already know just how important nutrition is to the health of your developing child.  You also may have heard about the importance of omega-3 fatty acids, such as docosahexaenoic acid (DHA), for the development of your baby’s brain and nervous system.  However, is it possible that consuming DHA during pregnancy could affect the health of your baby years into the future?  Increasingly, scientists are finding that this is the case.

A new study from a research group at the University of Kansas Medical Center found that changes in red blood cell DHA levels in pregnant women (following 600 mg per day DHA supplementation), were associated with improved body composition in children 5 years after birth (1).  This association was observed in a group of women-child pairs, where DHA supplementation was previously found to significantly reduce the risk of preterm birth (<34 weeks) gestational age, increase birth weight and increase birth length compared to placebo (2).  The observation that exposure to a single nutrient during pregnancy can have such a lasting effect on body composition is truly striking.

Some studies previously found an association between a mother’s consumption of omega-3 and/or omega-6 and childhood body composition.  For example, in a group of women-child pairs in Massachusetts, higher levels of eicosapentaenoic acid (EPA) and DHA in the diet or in the umbilical cord blood plasma were associated with lower body fat in 3 year old children (3).  In a UK population, higher blood plasma omega-6 levels in late pregnancy were positively associated with fat mass in 4 year old children (4).  In a Dutch cohort, higher maternal EPA and DHA levels were associated with lower childhood body fat percentage, while higher maternal omega-6 levels were associated with higher childhood body fat percentage (5).

So, what is the mechanism?
Scientists are still working to understand, but we already know that DHA is important for the developing brain and nervous system (6). It is possible that increasing the ratio of DHA omega-3 to ARA omega-6 during a critical developmental time window in pregnancy could influence how an unborn child’s brain is “programmed” to maintain a healthy body weight (7). It is recognized that making changes in the amount of each of these fatty acids, alters how our cells work. Lasting effects of a mother’s DHA supplementation have previously been observed for other health-related outcomes, including attention and fussiness in infants (8), occurrence of colds and illness symptom duration in infants (9), and attention of children at age 5 (10).

DHA can already be found in many foods, such as fatty fish (tuna and salmon) and prenatal supplements, but the research described above was conducted with higher amounts than typically found in food sources.  Although consuming fish is a great way to increase the DHA omega-3 content of your diet, important advisories exist regarding consumption of certain fish while pregnant.  Taking a DHA-rich fish oil or vegetarian algal DHA supplement is another way to assure that the unborn infant gets an optimum level of this important fatty acid for brain, nerve and eye development.

Improving nutrient status, especially DHA levels, during pregnancy may have a lasting impact on the future health of a child. Furthermore, DHA supplementation during pregnancy may also have a positive influence on body weight during the childhood years.