School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
J Nutr Biochem. 2013 Jul;24(7):1381-92. doi: 10.1016/j.jnutbio.2012.11.006. Epub 2013 Jan 18.
We investigated the changes in adiposity, cardiovascular and liver structure and function, and tissue fatty acid compositions in response to oleic acid-rich macadamia oil, linoleic acid-rich safflower oil and α-linolenic acid-rich flaxseed oil (C18 unsaturated fatty acids) in rats fed either a diet high in simple sugars and mainly saturated fats or a diet high in polysaccharides (cornstarch) and low in fat. The fatty acids induced lipid redistribution away from the abdomen, more pronounced with increasing unsaturation; only oleic acid increased whole-body adiposity. Oleic acid decreased plasma total cholesterol without changing triglycerides and nonesterified fatty acids, whereas linoleic and α-linolenic acids decreased plasma triglycerides and nonesterified fatty acids but not cholesterol. α-Linolenic acid improved left ventricular structure and function, diastolic stiffness and systolic blood pressure. Neither oleic nor linoleic acid changed the left ventricular remodeling induced by high-carbohydrate, high-fat diet, but both induced dilation of the left ventricle and functional deterioration in low fat-diet-fed rats. α-Linolenic acid improved glucose tolerance, while oleic and linoleic acids increased basal plasma glucose concentrations. Oleic and α-linolenic acids, but not linoleic acid, normalized systolic blood pressure. Only oleic acid reduced plasma markers of liver damage. The C18 unsaturated fatty acids reduced trans fatty acids in the heart, liver and skeletal muscle with lowered stearoyl-CoA desaturase-1 activity index; linoleic and α-linolenic acids increased accumulation of their C22 elongated products. These results demonstrate different physiological and biochemical responses to primary C18 unsaturated fatty acids in a rat model of human metabolic syndrome.
我们研究了富含油酸的澳洲坚果油、富含亚油酸的红花油和富含α-亚麻酸的亚麻籽油（C18 不饱和脂肪酸）对高糖和主要饱和脂肪饮食或高多糖（玉米淀粉）和低脂肪饮食的大鼠的体脂分布、心血管和肝脏结构与功能以及组织脂肪酸组成的影响。脂肪酸诱导脂质从腹部重新分布，不饱和程度越高，分布越明显；只有油酸增加了全身脂肪含量。油酸降低了血浆总胆固醇，而不改变甘油三酯和非酯化脂肪酸，而亚油酸和α-亚麻酸降低了血浆甘油三酯和非酯化脂肪酸，但不降低胆固醇。α-亚麻酸改善了左心室结构和功能、舒张僵硬和收缩压。无论是油酸还是亚油酸都没有改变高碳水化合物高脂肪饮食引起的左心室重构，但两者都引起了左心室扩张和低脂饮食喂养大鼠的功能恶化。α-亚麻酸改善了葡萄糖耐量，而油酸和亚油酸增加了基础血浆葡萄糖浓度。油酸和α-亚麻酸，而不是亚油酸，使收缩压正常化。只有油酸降低了血浆肝损伤标志物。C18 不饱和脂肪酸降低了心脏、肝脏和骨骼肌中的反式脂肪酸，同时降低了硬脂酰辅酶 A 去饱和酶-1 活性指数；亚油酸和α-亚麻酸增加了它们的 C22 伸长产物的积累。这些结果表明，在人类代谢综合征的大鼠模型中，初级 C18 不饱和脂肪酸具有不同的生理和生化反应。
