Cuchel M, Schwab U S, Jones P J, Vogel S, Lammi-Keefe C, Li Z, Ordovas J, McNamara J R, Schaefer E J, Lichtenstein A H
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
Metabolism. 1996 Feb;45(2):241-7. doi: 10.1016/s0026-0495(96)90061-x.
The effects of replacing corn oil with corn oil margarine in stick form on endogenous cholesterol synthesis and susceptibility of low-density lipoprotein (LDL) to oxidation were assessed in 14 middle-aged and elderly men and women aged 63 +/- 12 years (mean +/- SD) with moderate hypercholesterolemia (mean LDL-cholesterol [LDL-C], 4.24 +/- 0.59 mmol/L at the time of recruitment). Subjects consumed each of two diets for 32-day periods, one enriched in corn oil, which contained 30% of energy as fat (7% saturated fatty acid [SFA], 9% monounsaturated fatty acid [MUFA] [0.4% 18:1n9 trans], and 11% polyunsaturated fatty acid [PUFA]) and 85 mg cholesterol/4.2 MJ, and one enriched in stick corn oil margarine, which contained 30% fat (8% SFA, 12% MUFA [4.2% 18:1n9trans], and 8% PUFA) and 77 mg cholesterol/4.2 MJ. Both diets were isocaloric and supplied by a metabolic research kitchen. Mean total cholesterol levels were lowest (P = .039) when subjects consumed the corn oil-enriched diet (5.01 +/- 0.51 mmol/L) as compared with the margarine-enriched diet (5.30 +/- 0.58 mmol/L). LDL-C levels were 3.24 +/- 0.51 and 3.50 +/- 0.54 mmol/L when subjects consumed corn oil-and margarine-enriched diets, respectively (P = .058). There were no significant differences in high-density lipoprotein cholesterol (HDL-C) or triglyceride concentrations between the two experimental periods. Consumption of the margarine-enriched diet versus the corn oil-enriched diet tended to result in lower cholesterol fractional synthetic rates ([C-FSRs] 0.0466 +/- 0.0175 and 0.0668 +/- 0.0298, respectively, P = .080) and cholesterol absolute synthetic rates ([C-ASRs] 1.1761 +/- 0.5375 and 1.6954 +/- 0.8685, respectively, P = .092); however, differences did not reach statistical significance. Consumption of the margarine-enriched diet versus the corn oil-enriched diet resulted in a significantly higher concentration of alpha-tocopherol in both plasma and LDL(P = .004 and P = .011, respectively). LDL particle size tended to be smaller after subjects consumed the margarine-enriched diet versus the corn oil-enriched diet (P = .103). Susceptibility of LDL to oxidation was similar after consumption of the corn oil- and margarine-enriched diets. These data suggest that an increased rate of endogenous cholesterol synthesis did not contribute to the higher plasma cholesterol concentrations during the period when subjects consumed the margarine-enriched diet. Therefore, the increase in cholesterol concentration resulting from margarine consumption was likely attributable, at least in part, to a decreased catabolic rate of cholesterol. Additionally, susceptibility of LDL to in vitro oxidation was not altered by consumption of hydrogenated fat.
在14名年龄为63±12岁（均值±标准差）、患有中度高胆固醇血症（招募时平均低密度脂蛋白胆固醇[LDL-C]为4.24±0.59 mmol/L）的中老年男性和女性中，评估了用棒状玉米油人造黄油替代玉米油对内源性胆固醇合成以及低密度脂蛋白（LDL）氧化易感性的影响。受试者分别食用两种饮食各32天，一种富含玉米油，其脂肪提供30%的能量（7%饱和脂肪酸[SFA]，9%单不饱和脂肪酸[MUFA][0.4%反式18:1n9]，11%多不饱和脂肪酸[PUFA]）且每4.2兆焦耳含85毫克胆固醇；另一种富含棒状玉米油人造黄油，其脂肪含量为30%（8% SFA，12% MUFA[4.2%反式18:1n9]，8% PUFA）且每4.2兆焦耳含77毫克胆固醇。两种饮食均为等热量，由代谢研究厨房提供。与富含人造黄油的饮食（5.30±0.58 mmol/L）相比，受试者食用富含玉米油的饮食时平均总胆固醇水平最低（P = 0.039）（5.01±0.51 mmol/L）。受试者食用富含玉米油和富含人造黄油的饮食时，LDL-C水平分别为3.24±0.51和3.50±0.54 mmol/L（P = 0.058）。两个实验阶段的高密度脂蛋白胆固醇（HDL-C）或甘油三酯浓度无显著差异。与富含玉米油的饮食相比，食用富含人造黄油的饮食往往导致胆固醇分数合成率较低（分别为0.0466±0.0175和0.0668±0.0298，P = 0.080）以及胆固醇绝对合成率较低（分别为1.1761±0.5375和1.6954±0.8685，P = 0.092）；然而，差异未达到统计学显著性。与富含玉米油的饮食相比，食用富含人造黄油的饮食导致血浆和LDL中α-生育酚浓度显著更高（分别为P = 0.004和P = 0.011）。与食用富含玉米油的饮食相比，受试者食用富含人造黄油的饮食后LDL颗粒大小往往更小（P = 0.103）。食用富含玉米油和富含人造黄油的饮食后，LDL的氧化易感性相似。这些数据表明，在内源性胆固醇合成速率增加的情况下，受试者食用富含人造黄油的饮食期间血浆胆固醇浓度升高并非由此导致。因此，食用人造黄油导致的胆固醇浓度升高可能至少部分归因于胆固醇分解代谢速率降低。此外，氢化脂肪的摄入未改变LDL在体外的氧化易感性。
