Division of Nutritional Sciences, Cornell University,Ithaca,NY14853,USA.
Br J Nutr. 2014 Aug 28;112(4):565-72. doi: 10.1017/S0007114514001081. Epub 2014 May 15.
Branched-chain fatty acids (BCFA) are bioactive food components that constitute about 2 % of fatty acids in cows' milk fat. There are few systematic data available on the BCFA content of other foods to estimate dietary intakes. In the present study, we report BCFA distribution and content of fresh and processed foods representing the major foods in the American diet and estimate BCFA intake. BCFA are primarily components of dairy and ruminant food products, and are absent from chicken, pork and salmon. The mean BCFA intake of 500 mg/d was delivered primarily from dairy and beef food products; by comparison, average intake of the widely studied long-chain PUFA EPA and DHA has been estimated to be 100 mg/d. Common adjustments in the diet could double the daily intake of BCFA. The fermented foods sauerkraut and miso had appreciable fractions of BCFA, but, overall, they are low-fat foods providing very small amounts of BCFA in the diet, and other fermented foods did not contain BCFA as might have been expected from the influence of microbial exposure. These data support the quantitative importance of BCFA delivered primarily from dairy and beef food products and highlight the need for research into their effects on health.
支链脂肪酸（BCFA）是具有生物活性的食物成分，约占牛奶脂肪中脂肪酸的 2%。关于其他食物中 BCFA 含量的系统数据很少，无法据此估计饮食摄入量。本研究报告了代表美国饮食主要食物的新鲜和加工食品中的 BCFA 分布和含量，并估计了 BCFA 的摄入量。BCFA 主要是乳制品和反刍动物食品的成分，而鸡肉、猪肉和三文鱼中则没有。500mg/d 的 BCFA 摄入量主要来自乳制品和牛肉食品；相比之下，人们广泛研究的长链多不饱和脂肪酸 EPA 和 DHA 的平均摄入量估计为 100mg/d。饮食中的常见调整可以使 BCFA 的日摄入量增加一倍。发酵食品泡菜和味噌含有相当一部分的 BCFA，但总的来说，它们是低脂肪食品，在饮食中只提供非常少量的 BCFA，而其他发酵食品则没有 BCFA，这可能是由于微生物暴露的影响。这些数据支持了主要来自乳制品和牛肉食品的 BCFA 的定量重要性，并强调了需要研究它们对健康的影响。
