Polyunsaturated fatty acids (PUFAs) are fatty acids with two or more carbon-carbon double bonds. Their nomenclature is based on the position of where the first double bond is located. Omega-3 (n-3) PUFAs are generally the most well-known fatty acids for their support in a healthy response to inflammation and include eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). Omega-6 (n-6) PUFAs include arachidonic acid (ARA) and linoleic acid. 

DHA is found in the phospholipid bilayer of human cell membranes and has particular relevance to brain health. DHA makes up approximately 90% of brain n-3 PUFAs and 10-20% of the total lipids in the brain. DHA supports neurogenesis and neurotransmission and accumulates rapidly in the third trimester of pregnancy. Preterm births have been shown to result in lower neural tissue DHA levels and a higher incidence of poor neurobehavioral outcomes as compared to term-born infants. A randomized control trial is currently studying the long-term effects of DHA supplementation on behavioral outcomes in over 1,200 infants born prior to 29 weeks gestation. Additionally, a review article explored the importance of both DHA and ARA in fetal neurodevelopment and reported that the dietary balance of both molecules may influence brain function and development. Like DHA, ARA accumulates rapidly in the third trimester and in infancy. Increases in the Intelligence Quotient (IQ) have been observed in children whose birth parents consumed DHA during pregnancy and through the lactation period. Western diets generally tend to have a higher ratio of n-6:n-3 fatty acids and therefore supplementation with n-3 PUFAs was suggested by this study. 

A longitudinal study of over six thousand adolescents explored the relationship between the incidence of psychological disorders and PUFA intake. Total amounts of n-6 and n-3 levels were not associated with mental disorders, but subgroup analysis indicated that the balance of n-6:n-3 fatty acids was positively associated with psychotic disorder, depressive disorder, and generalized anxiety disorder. This is thought to be related to a potential increase in inflammation from a higher amount of n-6 PUFAs as compared to n-3. Future studies exploring the relationship between the n-6:n-3 ratio, neuroinflammation, and psychological disorders may provide more clinical relevance. 

A recent population study explored the supportive role of the Mediterranean diet on overall health and inflammatory markers in children and adolescents. The study findings correlated higher dietary PUFA intake in adolescents with lower serum levels of the inflammatory marker C-reactive protein (CRP), suggesting that consumption of PUFAs may support the body’s healthy response to inflammation in this population. While clinical research still has much yet to explore, PUFAs may help support brain health, a healthy mood, and a healthy response to inflammation in kids.

By Colleen Ambrose, ND, MAT