Effects of Docosahexaenoic Acid (DHA) on Cognitive Function in Children 4 Years of Age

DHA is the primary omega-3 fatty acid present in the brain and retina and plays crucial structural and functional roles in these issues. The primary dietary source of DHA is fatty fish (e.g., salmon, herring, tuna). The American diet provides one of the lowest levels of omega-3 fatty acids of most industrialized nations. Children between the ages of 1 and 5 years consume only 30 to 50 mg DHA per day despite high requirements for this nutrient to support growth and tissue turnover. Studies with human infants have reported visual and cognitive benefits of DHA supplementation in early life. Reported benefits include significant improvements on tests of visual acuity during infancy, psychomotor or mental development in the first two years of life, and problem-solving and sustained attention around 5 years of age. Few studies have evaluated the effect that DHA supplementation has on the cognitive function of older children. Studies that considered DHA supplementation in children 4-12 years of age with attention-deficit/hyperactivity disorder (ADHD) or other developmental disorders have shown improvements on several measures of attention, behavior, and executive function. Given the estimated high requirements of DHA to support growth and maintenance of the brain, the low consumption of DHA by American children, and the evidence from human and animal studies that DHA status affects the functional capacity of the central nervous system, there is a reasonable expectation that DHA supplementation administered to preschool-aged children will improve performance on tests of attention, memory, processing speed, and error rate.