Increasing dietary alpha-linolenic acid enhances tissue levels of long-chain n-3 PUFA when linoleic acid intake is low in hamsters.

摘要

This study investigated whether feeding hamsters diets varying in alpha-linolenic acid (ALA) content and low in linoleic acid (LA) could increase tissue levels of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) to the same extent as a fish oil-supplemented diet. For 5 wk, 60 hamsters were fed 1 of the following 5 diets containing 2% of total dietary energy (TE) as LA and either: 0.5% (diet A); 1% (diets B and E), 2% (diet C); or 4% (diet D) ALA of TE, so that the ratio of LA/ALA was 4:1, 2:1, 1:1 or 1:2. Diet E was supplemented with fish oil at the level of 0.2% of total energy intake. At the end of the study, overnight-fasted hamsters were sacrificed and blood and tissues were collected. Tissue levels of ALA, EPA, DPA and DHA rose in proportion to the increase in dietary ALA level (P < 0.01); however, levels of DHA reached a plateau at ALA intakes >1% (P < 0.01). These changes were accompanied by decreases in arachidonic acid with or without increases in LA levels (P < 0.01). Hamsters fed diet D had similar or higher EPA, DPA and DHA tissue levels to those fed diet E (P < 0.01). In hamsters, diets containing 4% energy as ALA and 2% energy as LA can increase tissue levels of EPA, DPA and DHA to the same extent as feeding 0.2% energy as fish oil.