Omega-3 supplementation during pregnancy altered children's brain metabolism a decade later. Digest
Children's brains have high metabolic demands that change as their brains mature, but whether nutrition during pregnancy can influence this developmental pattern years later is not well understood. A new study tested whether omega-3 fatty acids from fish oil taken during pregnancy could influence this process.
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Researchers followed children whose mothers had participated in a Danish randomized trial of omega-3 supplementation during pregnancy. From pregnancy week 24 until one week after birth, the women received capsules containing either 2.4 grams per day of long-chain omega-3 fatty acids (55% EPA and 37% DHA) or olive oil as a placebo. When the children were about 10 years old, the families were invited to return for assessments of the children's cognition, mental health, and brain metabolism. A total of 487 children underwent brain imaging, and 460 had usable data for at least one of three measures of brain metabolism, including whole brain blood flow, whole brain oxygen use, and lactate levels in one brain region as a marker related to glucose metabolism. The researchers then used this information to examine whether prenatal omega-3 supplementation was associated with differences in brain metabolism, and whether the brain metabolism measures were associated with mental health or cognition. They also compared the children's brain metabolism measures with data from 248 adults in earlier studies to see how they differed with age.
- The adults had lower brain blood flow, oxygen use, and lactate levels than the children, consistent with the decline in brain metabolism that occurs as the brain matures.
- Children in the prenatal omega-3 group had on average about 2.5% lower whole brain blood flow and about 8% lower brain oxygen use at rest than those in the placebo group. Lactate did not clearly differ between groups.
- The three brain metabolism measures were not clearly related to ADHD or autism diagnoses, parent-rated cognitive skills involving planning and self-control, or intelligence.
- Differences in snapshots of omega-3 blood levels did not clearly track with differences in brain metabolism. Higher maternal omega-3 levels before supplementation and higher omega-3 levels in the children at age 10 were not clearly associated with any of the children's three brain metabolism measures.
During childhood, the brain has high metabolic demands as it builds and refines neural connections and develops the insulating myelin around nerve fibers. These demands are reflected in brain blood flow and oxygen use, which rise through early childhood, peak around middle childhood, and then generally decline as the brain matures. Omega-3 fatty acids may influence this developmental process in several ways. DHA becomes part of the membranes surrounding brain cells, where it can affect how those membranes and their signaling proteins function, while EPA and DHA can also influence inflammatory signaling in the brain. Both pathways can influence how much energy brain cells use, providing a plausible link to the lower blood flow and oxygen use seen in the prenatal omega-3 group.
A key limitation is that brain metabolism was measured only once, so the study cannot show when the differences emerged or how they changed over time. The effects were also small, and brain metabolism measures can vary widely among children, which may make subtle differences harder to detect. Nevertheless, the findings suggest that prenatal omega-3 supplementation may influence later brain biology, making it worth discussing as part of routine pregnancy care. In Aliquot #100, I discuss factors that influence child development before conception, during pregnancy and infancy, and into the toddler and early childhood years.