Valsta L M, Salminen I, Aro A, Mutanen M
Department of Nutrition, National Public Health Institute, Helsinki, Finland.
Eur J Clin Nutr. 1996 Apr;50(4):229-35.
To examine the ability of alpha-linolenic acid (ALA) in low erucic acid rapeseed oil (RO) to compensate for the effects of a restriction in fish intake on plasma fatty acid composition.
Two times 6 weeks' randomized dietary intervention was used with blind crossover design in 40 healthy unconfined women and men (age 20-46y).
Subjects were assigned to two fish restricted diets, namely RO diet and Trisun-sunflower oil (TSO) diet, with similar proportions of saturated : monounsaturated : polyunsaturated fatty acids (11.5:17.5:8.5% of total energy, En%), but differing in their ALA content (2.2 and 0.3 En%) and n-6 : n-3-ratio (3 : 1 and 23 : 1, respectively). The fatty acid compositions of plasma triglycerides (TG), cholesterol esters (CE), and phospholipids (PL) were analyzed by gas chromatography. Dietary intake was evaluated based on 3- to 7-day food records.
The proportion of TG and CE ALA decreased on the TSO diet (from 1.6% to 0.9% and from 0.9% to 0.4%, respectively, P < 0.001) and increased on the RO diet (from 1.7% to 3.4% and from 0.9% to 1.3%, respectively, P < 0.001) compared to the baseline level. The proportion of eicosapentaenoic acid (EPA) in all three plasma fractions decreased on the TSO diet but not on the RO diet. The proportions of docosa-hexaenoic acid (DHA) decreased on both experimental diets and there was no difference in CE DHA between the diets. PL docosa-pentaenoic acid (DPA) and PL DHA remained at a higher level on the RO diet compared to the TSO diet (P < 0.001 and P < 0.05, respectively).
ALA is metabolized to EPA in humans to a significant extent. The degree to which rapeseed oil (ca 50g/day) affects the proportion of EPA resembled the effect of a weekly portion (50-100g) of fatty fish depending on the fat content of the fish.
研究低芥酸菜籽油（RO）中的α-亚麻酸（ALA）补偿鱼类摄入量受限对血浆脂肪酸组成影响的能力。
采用两次为期6周的随机饮食干预，对40名健康无限制的男女（年龄20 - 46岁）进行双盲交叉设计。
将受试者分为两种鱼类限制饮食，即RO饮食和三生葵花籽油（TSO）饮食，饱和脂肪酸：单不饱和脂肪酸：多不饱和脂肪酸的比例相似（占总能量的11.5:17.5:8.5%，En%），但ALA含量不同（分别为2.2和0.3 En%），n-6:n-3比例也不同（分别为3:1和23:1）。通过气相色谱法分析血浆甘油三酯（TG）、胆固醇酯（CE）和磷脂（PL）的脂肪酸组成。根据3至7天的食物记录评估饮食摄入量。
与基线水平相比，TSO饮食时TG和CE中ALA的比例下降（分别从1.6%降至0.9%和从0.9%降至0.4%，P < 0.001），RO饮食时则升高（分别从1.7%升至3.4%和从0.9%升至1.3%，P < 0.001）。TSO饮食时所有三种血浆组分中二十碳五烯酸（EPA）的比例下降，但RO饮食时未下降。两种实验饮食中二十二碳六烯酸（DHA）的比例均下降，且两种饮食的CE DHA无差异。与TSO饮食相比，RO饮食时PL二十二碳五烯酸（DPA）和PL DHA保持在较高水平（分别为P < 0.001和P < 0.05）。
ALA在人体内可大量代谢为EPA。菜籽油（约50克/天）对EPA比例的影响程度类似于每周一份（50 - 100克）富含脂肪鱼类的影响，具体取决于鱼的脂肪含量。
