Rudel L L, Johnson F L, Sawyer J K, Wilson M S, Parks J S
Department of Comparative Medicine, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157, USA.
Am J Clin Nutr. 1995 Aug;62(2):463S-470S. doi: 10.1093/ajcn/62.2.463S.
We tested the hypothesis that an increased content of n-6 polyunsaturated fatty acids (principally linoleic acid) in an atherogenic diet of nonhuman primates would decrease atherosclerosis by modifying the composition and decreasing the concentration of plasma low-density lipoprotein (LDL). A species readily susceptible to diet-induced atherosclerosis (cynomolgus monkey) was compared with a less-susceptible species (African green monkey) with dietary cholesterol concentration and saturated or polyunsaturated fat (40% of energy) as variables. In both species, cholesterol concentrations in whole plasma, LDL, and high-density lipoprotein (HDL) were 20-30% lower when polyunsaturated fat was fed, whereas dietary cholesterol increased LDL cholesterol three- to fourfold. LDL was enriched in cholesteryl oleate when saturated fat and cholesterol were fed. Dietary linoleic acid prevented cholesteryl oleate enrichment and promoted cholesteryl linoleate accumulation in LDL. At the same plasma cholesterol concentration, cynomolgus monkeys had higher LDL cholesterol and lower HDL-cholesterol concentrations than did African green monkeys. LDL particle size was significantly (P < 0.001) larger in the group of cynomolgus monkeys fed polyunsaturated fat but tended to be smaller in African green monkeys fed polyunsaturated fat. Dietary polyunsaturated fat protected against coronary artery atherosclerosis in both species. Thus, LDL particle size, per se, was not atherogenic; instead, coronary artery atherosclerosis and cholesteryl oleate enrichment of LDL were more highly correlated. This outcome suggests that information about LDL composition may be more important for understanding the pathogenesis of atherosclerosis than previously suspected.
在非人灵长类动物的致动脉粥样硬化饮食中，增加n-6多不饱和脂肪酸（主要是亚油酸）的含量，会通过改变血浆低密度脂蛋白（LDL）的组成并降低其浓度来减轻动脉粥样硬化。将一种易患饮食诱导性动脉粥样硬化的物种（食蟹猴）与一种不易患的物种（非洲绿猴）进行比较，饮食中的胆固醇浓度以及饱和或多不饱和脂肪（占能量的40%）作为变量。在这两个物种中，喂食多不饱和脂肪时，全血浆、LDL和高密度脂蛋白（HDL）中的胆固醇浓度降低了20%-30%，而饮食中的胆固醇使LDL胆固醇增加了三到四倍。喂食饱和脂肪和胆固醇时，LDL富含油酸胆固醇酯。饮食中的亚油酸可防止油酸胆固醇酯富集，并促进LDL中亚油酸胆固醇酯的积累。在相同的血浆胆固醇浓度下，食蟹猴的LDL胆固醇浓度高于非洲绿猴，而HDL胆固醇浓度低于非洲绿猴。喂食多不饱和脂肪的食蟹猴组中，LDL颗粒大小显著更大（P<0.001），而喂食多不饱和脂肪的非洲绿猴组中，LDL颗粒大小则倾向于更小。饮食中的多不饱和脂肪对这两个物种的冠状动脉粥样硬化均有保护作用。因此，LDL颗粒大小本身并不具有致动脉粥样硬化性；相反，冠状动脉粥样硬化与LDL的油酸胆固醇酯富集之间的相关性更高。这一结果表明，关于LDL组成的信息对于理解动脉粥样硬化的发病机制可能比之前认为的更为重要。
