Epidemiological and experimental studies have indicated that consumption of more n-3 long-chain
polyunsaturated fatty acids may reduce the risk for a variety of diseases, including cardiovascular, neurological and immunological disorders, diabetes and
cancer. This article focuses on the role of marine n-3 long-chain
polyunsaturated fatty acids in brain functions, including the development of the central nervous system and
neurological disorders. An overview of the major animal studies and clinical trials is provided here, focusing on
fatty acid supplementation during pregnancy and infancy, and prevention and management of
Alzheimer's disease,
schizophrenia, depression and attention deficit hyperactive disorder. Although an optimal balance in n-3/n-6 long-chain
polyunsaturated fatty acid ratio is important for proper neurodevelopment and cognitive functions, results from randomized controlled trials are controversial and do not confirm any useful effect of supplementation on development of preterm and term infants. The relationship between
fatty acid status and
mental disorders is confirmed by reduced levels of n-3 long-chain
polyunsaturated fatty acids in erythrocyte membranes of patients with
central nervous system disorders. Nevertheless, there are very little data supporting the use of
fish oil in those patients. The only way to verify whether n-3 long-chain
polyunsaturated fatty acids are a potential therapeutic option in the management and prevention of
mental disorders is to conduct a large definitive randomized controlled trials similar to those required for the licensing of any new pharmacological treatment.