The long-chain omega-3 polyunsaturated fatty acids, found predominantly in marine oils, are important for brain development during both the foetal and postnatal period. They play important roles in neuronal growth, development of neural cell interaction, and expression of genes regulating cell differentiation and growth.
The fetus and placenta are dependent on maternal essential fatty acids supply for their growth and development, with DHA (docosahexaenoic acid) supplemented infants showing significantly greater mental and psychomotor development scores (breast-fed children do even better). Dietary DHA is needed for the optimum functional maturation of the retina and visual cortex, with visual acuity and mental development seemingly improved by extra DHA. Aging is also associated with decreased brain levels of DHA: fish consumption is associated with decreased risk of dementia and Alzheimer’s disease, and the reported daily use of fish-oil supplements has been linked to improved cognitive function scores, but confirmation of these effects is needed.