Hodges R E, Salel A F, Dunkley W L, Zelis R, McDonagh P F, Clifford C, Hobbs R K, Smith L M, Fan A, Mason D T, Lykke C
Am J Clin Nutr. 1975 Oct;28(10):1126-40. doi: 10.1093/ajcn/28.10.1126.
Twenty-five young couples consumed either a saturated or polyunsaturated fat diet for a 20-week period. The polyunsaturated beef, lamb and dairy products, high in linoleic acid, were produced by feeding ruminant animals "protected lipid" feeds which prevent hydrogenation of fats in the rumen. The experimental design provided for four dietary groups: A) saturated diet for 20 weeks; B) polyunsaturated diet for 20 weeks; C) saturated diet for 10 weeks then polyunsaturated diet for 10 weeks; and D) polyunsaturated for 10 weeks then saturated diet for 10 weeks. Polyunsaturated-to-saturated ratios (linoleic: total saturated fatty acids) for the diets were: prestudy, 0.43-0.56; saturated 0.11-0.14; polyunsaturated, 0.56-0.62. Factors other than diet that appeared to affect cholesterol responses were carefully considered. During the initial 3 weeks (regimentation period) plasma cholesterol concentration decreased in all groups irrespective of diet. This was followed by two experimental periods in which the effects of the prescribed diets were readily apparent (response periods I and II). The final 4 weeks of the study were characterized by diminishing compliance with the dietary discipline (abatement period). Subjects in each group (A,B,C,D) were subdivided into high and low on a basis of each group's initial median cholesterol level. Those in the high subgroups were very responsive to dietary changes whereas those in the low subgroups were not. Combined responses of high subjects were: polyunsaturated diet, -10.7 mg/dl (P less than 0.025), saturated diet, d8 mg/dl (P less than 0.05). Combined difference between saturated and polyunsaturated diets was 18.5 mg/dl or approximately a 10% cholesterol difference between the experimental polyunsaturated and saturated diets.
25对年轻夫妇在20周的时间里分别食用饱和脂肪饮食或多不饱和脂肪饮食。富含亚油酸的多不饱和牛肉、羊肉和乳制品是通过给反刍动物喂食“保护脂质”饲料生产的，这种饲料可防止瘤胃中的脂肪氢化。实验设计了四个饮食组：A）20周的饱和脂肪饮食；B）20周的多不饱和脂肪饮食；C）10周的饱和脂肪饮食，然后是10周的多不饱和脂肪饮食；D）10周的多不饱和脂肪饮食，然后是10周的饱和脂肪饮食。这些饮食的多不饱和脂肪与饱和脂肪的比例（亚油酸：总饱和脂肪酸）为：研究前，0.43 - 0.56；饱和脂肪饮食，0.11 - 0.14；多不饱和脂肪饮食，0.56 - 0.62。仔细考虑了除饮食之外其他可能影响胆固醇反应的因素。在最初的3周（适应期），所有组的血浆胆固醇浓度均下降，与饮食无关。随后是两个实验期，在此期间规定饮食的效果很明显（反应期I和II）。研究的最后4周的特点是对饮食规定的依从性降低（缓解期）。每组（A、B、C、D）的受试者根据每组最初的胆固醇中位数水平分为高胆固醇组和低胆固醇组。高胆固醇亚组的受试者对饮食变化反应非常敏感，而低胆固醇亚组的受试者则不然。高胆固醇受试者的综合反应为：多不饱和脂肪饮食，-10.7毫克/分升（P < 0.025），饱和脂肪饮食，+8毫克/分升（P < 0.05）。饱和脂肪饮食和多不饱和脂肪饮食之间的综合差异为18.5毫克/分升，即实验性多不饱和脂肪饮食和饱和脂肪饮食之间的胆固醇差异约为10%。
