Innis Sheila M
Nutrition Research Program, Child and Family Research Institute, Department of Paediatrics, University of British Columbia, 950 West 28th Avenue, Vancouver, B.C., Canada.
Brain Res. 2008 Oct 27;1237:35-43. doi: 10.1016/j.brainres.2008.08.078. Epub 2008 Sep 9.
The omega-3 fatty acids are essential dietary nutrients and one of their important roles is providing the fatty acid with 22 carbons and 6 double bonds known as docosahexaenoic acid (DHA) for nervous tissue growth and function. Inadequate intakes of omega-3 fatty acids decrease DHA and increase omega-6 fatty acids in the brain. Decreased DHA in the developing brain leads to deficits in neurogenesis, neurotransmitter metabolism, and altered learning and visual function in animals. Western diets are low in omega-3 fatty acids, including the 18 carbon omega-3 fatty acid alpha linolenic acid found mainly in plant oils, and DHA, which is found mainly in fish. The DHA status of the newborn and breast-fed infant depends on the maternal intake of DHA and varies widely. Epidemiological studies have linked low maternal DHA to increased risk of poor child neural development. Intervention studies have shown improving maternal DHA nutrition decreases the risk of poor infant and child visual and neural development. Thus, sufficient evidence is available to conclude that maternal fatty acid nutrition is important to DHA transfer to the infant before and after birth, with short and long-term implications for neural function. However, genetic variation in genes encoding fatty acid desaturases also influence essential fatty acid metabolism, and may increase requirements in some individuals. Consideration of omega-3 fatty acid to include brain development, optimizing omega-3 and omega-6 fatty acids in gestation and lactation, and in fatty acid nutrition support for intravenous and formula-fed neonates is important.
ω-3脂肪酸是必需的膳食营养素，其重要作用之一是为神经组织的生长和功能提供一种含有22个碳原子和6个双键的脂肪酸，即二十二碳六烯酸（DHA）。ω-3脂肪酸摄入不足会导致大脑中DHA含量降低，ω-6脂肪酸含量升高。发育中的大脑中DHA含量降低会导致动物神经发生、神经递质代谢出现缺陷，并改变学习和视觉功能。西方饮食中ω-3脂肪酸含量较低，包括主要存在于植物油中的18碳ω-3脂肪酸α-亚麻酸，以及主要存在于鱼类中的DHA。新生儿和母乳喂养婴儿的DHA状况取决于母亲对DHA的摄入量，且差异很大。流行病学研究表明，母亲DHA水平低与儿童神经发育不良风险增加有关。干预研究表明，改善母亲的DHA营养状况可降低婴儿和儿童视觉及神经发育不良的风险。因此，有充分证据可以得出结论，母亲的脂肪酸营养对于出生前后向婴儿传递DHA非常重要，对神经功能具有短期和长期影响。然而，编码脂肪酸去饱和酶的基因中的遗传变异也会影响必需脂肪酸的代谢，可能会增加某些个体的需求。考虑ω-3脂肪酸对大脑发育的影响、在妊娠和哺乳期优化ω-3和ω-6脂肪酸，以及为静脉营养和配方奶喂养的新生儿提供脂肪酸营养支持非常重要。
