n-3 fatty acid deficiency in man

A total of nine patients with n-3 fatty acid deficiency are described. They had been fed by gastric tube for 2.5-12 years, and had received 0.02-0.09% of calories as n-3 acids. The observed clinical symptoms of n-3 fatty acid deficiency were scaly and haemorrhagic dermatitis, haemorrhagic folliculitis of the scalp, growth retardation and impaired wound healing. All patients had extensive brain damage making it impossible to evaluate n-3 effects on cerebral functions. The patients were supplemented with cod liver and soya oil, alpha-linolenate followed by a purified fish oil, or with a mixture of linseed and cod liver oil. The results indicate that a dietary supply of 1.0-1.2% of alpha-linolenic acid is necessary to obtain a mid-normal lipid concentration of n-3 fatty acids, and suggest that the minimal dietary requirement is 0.2-0.3% of total calories. Long-chain n-3 fatty acids seem to be approximately twice as efficient as alpha-linolenic acid in maintaining normal n-3 fatty acid concentrations in plasma and red cell lipids.