MacDonald-Wicks Lesley K, Garg Manohar L
Nutrition & Dietetics, University of Newcastle, New South Wales, Australia.
Lipids. 2004 Jun;39(6):545-51. doi: 10.1007/s11745-004-1261-z.
The health benefits of long-chain n-3 PUFA (20:5n-3 and 22:6n-3) depend on the extent of incorporation of these FA into plasma and tissue lipids. This study aimed to investigate the effect of the background dietary fat (saturated, monounsaturated, or n-6 polyunsaturated) on the quantitative incorporation of dietary 18:3n-3 and its elongated and desaturated products into the plasma and the liver lipids of rats. Female weanling Wistar rats (n = 54) were randomly assigned to six diet groups (n = 9). The fat added to the semipurified diets was tallow (SFA), tallow plus linseed oil (SFA-LNA), sunola oil (MUFA), sunola oil plus linseed oil (MUFA-LNA), sunflower oil (PUFA), or sunflower oil plus linseed oil (PUFA-LNA). At the completion of the 4-wk feeding period, quantitative FA analysis of the liver and plasma was undertaken by GC. The inclusion of linseed oil in the rat diets increased the level of 18:3n-3, 20:5n-3, and, to a smaller degree, 22:6n-3 in plasma and liver lipids regardless of the background dietary fat. The extent of incorporation of 18:3n-3, 20:5n-3, and 22:5n-3 followed the order SFA-LNA > MUFA-LNA > PUFA-LNA. Levels of 22:6n-3 were increased to a similar extent regardless of the type of major fat in the rat diets. This indicates that the background diet affects the incorporation in liver and plasma FA pools of the n-3 PUFA with the exception of 22:6n-3 and therefore the background diet has the potential to influence the already established health benefits of long-chain n-3 fatty acids.
长链n-3多不饱和脂肪酸（20:5n-3和22:6n-3）对健康的益处取决于这些脂肪酸掺入血浆和组织脂质中的程度。本研究旨在调查基础膳食脂肪（饱和脂肪、单不饱和脂肪或n-6多不饱和脂肪）对膳食18:3n-3及其延长和去饱和产物定量掺入大鼠血浆和肝脏脂质的影响。将雌性断乳Wistar大鼠（n = 54）随机分为六个饮食组（n = 9）。添加到半纯化饮食中的脂肪分别是牛油（饱和脂肪酸）、牛油加亚麻籽油（饱和脂肪酸-亚麻酸）、葵花籽油（单不饱和脂肪酸）、葵花籽油加亚麻籽油（单不饱和脂肪酸-亚麻酸）、向日葵油（多不饱和脂肪酸）或向日葵油加亚麻籽油（多不饱和脂肪酸-亚麻酸）。在4周喂养期结束时，通过气相色谱法对肝脏和血浆进行脂肪酸定量分析。无论基础膳食脂肪如何，在大鼠饮食中添加亚麻籽油都会增加血浆和肝脏脂质中18:tn-己酸、20:5n-3的水平，以及程度较小的22:6n-3的水平。18:3n-3、20:5n-3和22:5n-3的掺入程度顺序为饱和脂肪酸-亚麻酸>单不饱和脂肪酸-亚麻酸>多不饱和脂肪酸-亚麻酸。无论大鼠饮食中主要脂肪的类型如何，22:6n-3的水平升高程度相似。这表明基础饮食会影响n-3多不饱和脂肪酸在肝脏和血浆脂肪酸库中的掺入，但22:6n-3除外，因此基础饮食有可能影响长链n-3脂肪酸已确立的健康益处。
