Hunter J E
Department of Chemistry, University of Cincinnati, Ohio 45221-0172, USA.
Lipids. 2001 Jul;36(7):655-68. doi: 10.1007/s11745-001-0770-0.
This article reviews published literature on how the stereospecific structure of dietary triglycerides may affect lipid metabolism in humans. Animal studies have shown enhanced absorption of fatty acids in the sn-2 position of dietary triglycerides. Increasing the level of the saturated fatty acid palmitic acid in the sn-2 position (e.g., by interesterification of the fat to randomize the positions of the fatty acids along the glycerol backbone) has been shown in rabbits to increase the atherogenic potential of the fat without impacting levels of blood lipids and lipoproteins. In contrast, enhancing the level of stearic acid in the sn-2 position has not been found to affect either atherogenic potential or levels of blood lipids and lipoproteins in rabbits. Fatty acids other than palmitic and stearic have not been studied systematically with respect to possible positional effects. A limited number of human studies have shown no significant effects of interesterified fats on blood lipid parameters. However, it is unknown whether modifying the stereospecific structure of dietary triglycerides would affect atherogenicity or other long-term health conditions in humans. It is possible that incorporation of palmitic acid into the sn-2 position of milk fat is beneficial to the human infant (as a source of energy for growth and development) but not to human adults. Additional research is needed to determine whether processes like interesterification, which can be used to alter physical parameters of dietary fats (e.g., melting characteristics), may result in favorable or unfavorable long-term effects in humans.
本文综述了已发表的关于膳食甘油三酯的立体特异性结构如何影响人类脂质代谢的文献。动物研究表明，膳食甘油三酯sn-2位脂肪酸的吸收增强。在兔子中，提高sn-2位饱和脂肪酸棕榈酸的水平（例如，通过脂肪酯交换使脂肪酸在甘油主链上的位置随机化）已显示会增加脂肪的致动脉粥样硬化潜力，而不影响血脂和脂蛋白水平。相比之下，提高sn-2位硬脂酸的水平在兔子中未发现会影响致动脉粥样硬化潜力或血脂和脂蛋白水平。除棕榈酸和硬脂酸外的其他脂肪酸尚未就可能的位置效应进行系统研究。少数人体研究表明，酯交换脂肪对血脂参数无显著影响。然而，改变膳食甘油三酯的立体特异性结构是否会影响人类的动脉粥样硬化性或其他长期健康状况尚不清楚。将棕榈酸掺入乳脂肪的sn-2位可能对人类婴儿有益（作为生长和发育的能量来源），但对成年人则不然。需要进一步研究来确定诸如酯交换等可用于改变膳食脂肪物理参数（如熔点特性）的过程是否会对人类产生有利或不利的长期影响。
