α-Linolenic acid metabolism in adult humans: the effects of gender and age on conversion to longer-chain polyunsaturated fatty acids
✍ Scribed by Graham C. Burdge; Philip C. Calder
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 292 KB
- Volume
- 107
- Category
- Article
- ISSN
- 1438-7697
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✦ Synopsis
AE-Linolenic acid metabolism in adult humans: the effects of gender and age on conversion to longer-chain polyunsaturated fatty acids
This review summarises and evaluates current knowledge of a-linolenic acid (aLNA) metabolism in adult humans. The principal biological role of aLNA appears to be as a precursor for the synthesis of longer-chain n-3 polyunsaturated fatty acids (PUFA). Stable isotope tracer studies indicate that conversion of aLNA to eicosapentaenoic acid (EPA) occurs but is limited in men and that further transformation to docosahexaenoic acid (DHA) is very low. A lower proportion of aLNA is used for b-oxidation in women compared with men, while the fractional conversion to the longer-chain n-3 PUFA is greater, possibly due to the regulatory effects of oestrogen. Increasing aLNA intake for a period of weeks results in an increase in the proportion of EPA in plasma lipids, circulating cells and breast milk, but there is no increase in DHA, which may even decline in some pools at high aLNA intakes. Overall, aLNA appears to be a limited source of longer-chain n-3 PUFA in man, and so adequate intakes of preformed longchain n-3 PUFA, in particular DHA, may be important for maintaining optimal tissue function. The capacity to up-regulate aLNA transformation in women may be important for meeting the demands of the foetus and neonate for DHA.