Cuevas A M, Irribarra V L, Castillo O A, Yañez M D, Germain A M
Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica, Santiago, Chile.
Eur J Clin Nutr. 2003 Aug;57(8):889-94. doi: 10.1038/sj.ejcn.1601622.
Postmenopausia and hypercholesterolemia are related to endothelial dysfunction, a pathogenic event in atherosclerosis. Soy protein reduces plasma cholesterol, but there is scanty information about its effect on endothelial function.
To evaluate the effect of isolated soy protein compared to caseinate on plasma lipoproteins and endothelial function in postmenopausal hypercholesterolemic women.
Randomized, double-blind, cross-over trial.
Outpatient clinic of the Catholic University of Chile.
Eighteen healthy, postmenopausal women with hypercholesterolemia were recruited, included and completed the protocol.
During the trial, all patients followed a low fat/low cholesterol diet and were randomly assigned to receive isolated soy protein or matching caseinate for 4 weeks, and then the alternative treatment until week 8. At pre-study and at the end of the first and second period, plasma lipoprotein levels and endothelial function (flow-mediated dilatation (FMD) of the brachial artery) were evaluated.
Plasma total and low density lipoprotein (LDL)-cholesterol concentration were significantly lower with the low fat/low cholesterol diet compared to pre-study, either with caseinate or soy protein. No significant differences in plasma lipid concentration between caseinate or soy protein interventions were observed. FMD did not change with the caseinate. In contrast, when soy protein was administered, FMD was significantly higher compared to pre-study (9.4+/-1.8% vs 5.3+/-1.2%; P<0.05) and compared to caseinate intervention (9.4+/-1.8% vs 4.9+/-1.5%; P<0.033).
These results suggest that in postmenopausal hypercholesterolemic women, soy protein improves endothelial function, regardless of changes in plasma lipoproteins.
绝经后期和高胆固醇血症与内皮功能障碍相关，内皮功能障碍是动脉粥样硬化中的一个致病事件。大豆蛋白可降低血浆胆固醇，但关于其对内皮功能影响的信息却很少。
评估分离大豆蛋白与酪蛋白酸盐相比，对绝经后高胆固醇血症女性血浆脂蛋白和内皮功能的影响。
随机、双盲、交叉试验。
智利天主教大学门诊。
招募了18名健康的绝经后高胆固醇血症女性，她们均纳入并完成了该方案。
在试验期间，所有患者遵循低脂/低胆固醇饮食，并被随机分配接受分离大豆蛋白或匹配的酪蛋白酸盐治疗4周，然后交替治疗至第8周。在研究前以及第一和第二阶段结束时，评估血浆脂蛋白水平和内皮功能（肱动脉血流介导的舒张功能（FMD））。
与研究前相比，无论是食用酪蛋白酸盐还是大豆蛋白，低脂/低胆固醇饮食后血浆总胆固醇和低密度脂蛋白（LDL）胆固醇浓度均显著降低。酪蛋白酸盐或大豆蛋白干预之间的血浆脂质浓度未观察到显著差异。酪蛋白酸盐治疗后FMD没有变化。相比之下，服用大豆蛋白时，FMD与研究前相比显著升高（9.4±1.8% 对5.3±1.2%；P<0.05），与酪蛋白酸盐干预相比也显著升高（9.4±1.8% 对4.9±1.5%；P<0.033）。
这些结果表明，在绝经后高胆固醇血症女性中，大豆蛋白可改善内皮功能，而与血浆脂蛋白的变化无关。
