Kratz M, Cullen P, Kannenberg F, Kassner A, Fobker M, Abuja P M, Assmann G, Wahrburg U
Institute of Arteriosclerosis Research at the University of Münster, Münster, Germany.
Eur J Clin Nutr. 2002 Jan;56(1):72-81. doi: 10.1038/sj.ejcn.1601288.
The objective of this study was to compare the effects of dietary monounsaturated fatty acids (MUFA), n-6 and n-3 polyunsaturated fatty acids (PUFA) on LDL composition and oxidizability.
DESIGN, SETTING AND SUBJECTS: Sixty-nine healthy young volunteers, students at a nearby college, were included. Six subjects withdrew because of intercurrent illness and five withdrew because they were unable to comply with the dietary regimen.
The participants received a 2-week wash-in diet rich in saturated fatty acids (SFA) followed by diets rich in refined olive oil, rapeseed oil or sunflower oil for 4 weeks. Intakes of vitamin E and other antioxidants did not differ significantly between the diets.
At the end of the study, LDL oxidizability was lowest in the olive oil group (lag time: 72.6 min), intermediate in the rapeseed oil group (68.2 min) and highest in the sunflower oil group (60.4 min, P<0.05 for comparison of all three groups). Despite wide variations in SFA intake, the SFA content of LDL was not statistically different between the four diets (25.8-28.5% of LDL fatty acids). By contrast, the PUFA (43.5%-60.5% of LDL fatty acids) and MUFA content of LDL (13.7-29.1% of LDL fatty acids) showed a wider variability dependent on diet.
Enrichment of LDL with MUFA reduces LDL susceptibility to oxidation. As seen on the rapeseed oil diet this effect is independent of a displacement of higher unsaturated fatty acids from LDL. Evidence from this diet also suggests that highly unsaturated n-3 fatty acids in moderate amounts do not increase LDL oxidizability when provided in the context of a diet rich in MUFA.
本研究旨在比较膳食单不饱和脂肪酸（MUFA）、n-6和n-3多不饱和脂肪酸（PUFA）对低密度脂蛋白（LDL）组成和氧化易感性的影响。
设计、地点和受试者：纳入了69名健康的年轻志愿者，他们是附近一所大学的学生。6名受试者因并发疾病退出，5名受试者因无法遵守饮食方案而退出。
参与者先接受为期2周的富含饱和脂肪酸（SFA）的导入饮食，随后分别接受富含精炼橄榄油、菜籽油或葵花籽油的饮食4周。各饮食中维生素E和其他抗氧化剂的摄入量无显著差异。
研究结束时，橄榄油组的LDL氧化易感性最低（延迟时间：72.6分钟），菜籽油组居中（68.2分钟），葵花籽油组最高（60.4分钟，三组比较P<0.05）。尽管SFA摄入量差异很大，但四种饮食之间LDL的SFA含量无统计学差异（占LDL脂肪酸的25.8%-28.5%）。相比之下，LDL的PUFA含量（占LDL脂肪酸的43.5%-60.5%）和MUFA含量（占LDL脂肪酸的13.7%-29.1%）因饮食不同而有更大的变异性。
用MUFA富集LDL可降低LDL的氧化敏感性。如在菜籽油饮食中所见，这种作用与LDL中高度不饱和脂肪酸的置换无关。该饮食的证据还表明，在富含MUFA的饮食中适量摄入高度不饱和的n-3脂肪酸不会增加LDL的氧化易感性。
