Is docosahexaenoic acid, an n-3 long-chain polyunsaturated fatty acid, required for development of normal brain function? An overview of evidence from cognitive and behavioral tests in humans and animals

• Published in: The American journal of clinical nutrition Vol. 82; no. 2; pp. 281 - 295
• Main Authors: McCann, Joyce C, Ames, Bruce N
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01-08-2005; American Society for Clinical Nutrition, Inc
• Subjects: animal models; Animals; Behavior, Animal; Biological and medical sciences; Brain; Brain - growth & development; Brain - physiology; breast feeding; Cognition; Cognition & reasoning; cognitive development; consciousness; dietary fat; Dietary Supplements; docosahexaenoic acid; Docosahexaenoic Acids - administration & dosage; Docosahexaenoic Acids - analysis; Docosahexaenoic Acids - metabolism; Fatty acids; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; gamma-linolenic acid; Humans; infant feeding; infant formulas; infants; learning; literature reviews; Maze Learning; memory; Neurology; neurophysiology; omega-3 fatty acids; perinatal period; Primates; Randomized Controlled Trials as Topic; Rats; Research Design; rodents; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Memory; Central nervous system; Lipids; Infant; Cognition; Review; n-3 fatty acids; Docosahexaenoic acid; n-3 fatty acid; Encephalon; Learning; Acquisition process; Development; Primates; Essential fatty acid; Supplementation; Child; neurology; Human; LCPUFAs; Feeding behavior; infants; childhood; Long chain; Rodentia; Polyunsaturated fatty acid; brain; nonhuman primate studies; rodent studies; Feeding; essential fatty acids; formula feeding; Vertebrata; Long-chain polyunsaturated fatty acids; Mammalia; Linolenic acid; Animal; Unsaturated fatty acid; breastfeeding; DHA; perinatal period
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/82.2.281

This review is part of a series intended for nonspecialists that will summarize evidence relevant to the question of whether causal relations exist between micronutrient deficiencies and brain function. Here, we focus on experiments that used cognitive or behavioral tests as outcome measures in experimental designs that were known to or were likely to result in altered brain concentrations of the n-3 fatty acid docosahexaenoic acid (DHA) during the perinatal period of "brain growth spurt." Experimental designs reviewed include observational breastfeeding studies and randomized controlled trials in humans and studies in rodents and nonhuman primates. This review is based on a large number of expert reviews and commentaries and on some 50 recent studies in humans and animals that have not yet been included in published reviews. Expert opinion regarding the strengths and weaknesses of the major experimental systems and uncertainties associated with interpreting results is summarized. On the basis of our reading of this literature, we conclude that evidence from several types of studies, particularly studies in animals, suggests that, within the context of specific experimental designs, changes in brain concentrations of DHA are positively associated with changes in cognitive or behavioral performance. Additional experimental information required to conclude that a causal association exists is discussed, as are uncertainties associated with applying results from specific experimental designs to the question of whether infant formula should be supplemented with DHA.