Valenzuela A, Morgado N
Laboratorio de Lípidos y Antioxidantes, INTA, Universidad de Chile, Santiago, Chile.
Biol Res. 1999;32(4):273-87. doi: 10.4067/s0716-97601999000400007.
Trans fatty acids are unsaturated fatty acids with at least one double bond in the trans configuration. These fatty acids occur naturally in dairy and other natural fats and in some plants. However, industrial hydrogenation of vegetable or marine oils is largely the main source of trans fatty acids in our diet. The metabolic effect of trans isomers are today a matter of controversy generating diverse extreme positions in light of biochemical, nutritional, and epidemiological studies. Trans fatty acids also have been implicated in the etiology of various metabolic and functional disorders, but the main concern about its health effects arose because the structural similarity of these isomers to saturated fatty acids, the lack of specific metabolic functions, and its competition with essential fatty acids. The ingestion of trans fatty acids increases low density lipoprotein (LDL) to a degree similar to that of saturated fats, but it also reduces high density lipoproteins (HDL), therefore trans isomers are considered more atherogenic than saturated fatty acids. Trans isomers increase lipoprotein(a), a non-dietary-related risk of atherogenesis, to levels higher than the corresponding chain-length saturated fatty acid. There is little evidence that trans fatty acids are related to cancer risk at any of the major cancer sites. Considerable improvement has been obtained with respect to the metabolic effect of trans fatty acids due the development of analytical procedures to evaluate the different isomers in both biological and food samples. The oleochemical food industries have developed several strategies to reduce the trans content of hydrogenated oils, and now margarine and other hydrogenated-derived products containing low trans or virtually zero trans are available and can be obtained in the retail market. The present review provides an outline of the present status of trans fatty acids including origin, analytical procedures, estimated ingestion, metabolic effects, efforts to reduce trans isomers in our diet, and considerations for future prospects on trans isomers.
反式脂肪酸是至少含有一个反式构型双键的不饱和脂肪酸。这些脂肪酸天然存在于乳制品和其他天然脂肪以及一些植物中。然而，植物油或海洋油的工业氢化在很大程度上是我们饮食中反式脂肪酸的主要来源。鉴于生化、营养和流行病学研究，反式异构体的代谢效应如今是一个存在争议的问题，引发了各种极端观点。反式脂肪酸还与各种代谢和功能紊乱的病因有关，但其对健康影响的主要担忧源于这些异构体与饱和脂肪酸的结构相似性、缺乏特定的代谢功能以及与必需脂肪酸的竞争。摄入反式脂肪酸会使低密度脂蛋白（LDL）升高到与饱和脂肪相似的程度，但它也会降低高密度脂蛋白（HDL），因此反式异构体被认为比饱和脂肪酸更具致动脉粥样硬化性。反式异构体使脂蛋白（a）升高，这是一种与饮食无关的动脉粥样硬化风险，其水平高于相应链长的饱和脂肪酸。几乎没有证据表明反式脂肪酸与任何主要癌症部位的癌症风险有关。由于开发了评估生物和食品样本中不同异构体的分析程序，反式脂肪酸的代谢效应已取得了相当大的进展。油脂化学食品工业已制定了多种策略来降低氢化油中的反式含量，现在含有低反式或几乎零反式的人造黄油和其他氢化衍生产品在零售市场上可以买到。本综述概述了反式脂肪酸的现状，包括其来源、分析程序、估计摄入量、代谢效应、减少我们饮食中反式异构体的努力以及对反式异构体未来前景的考虑。
