Journal Name:
American Journal of Clinical Nutrition
Article Title:
Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish eating meat-eaters, vegetarians and vegans and the precursor-product ratio of alpha-linolenic acid to long-chain n-3 polyunsaturated acids: results from the EPIC-Norfolk cohort.
Date Written:
2010
Volume:
92
Number:
5
Page:
1040
Author(s):
Welch, A.A; Shakya-Shrestha, S; Lentjes, M.A.H; Wareham, N.J; Khaw, K.T.
Article:
An adequate n-3 polyunsaturated fatty acid (PUFA) status is important for the maintenance of health and could reduce the risk of chronic inflammatory disease, such as coronary artery disease and, potentially, dementia, diabetes, and asthma. Although alpha-linolenic acid (ALA) may be converted to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), research suggests this may be limited. As fish is the major source of EPA and DHA, non-fish eaters are at risk of low or inadequate n-3 PUFA status. Previous research has found that although non-fish eaters have much lower intakes of EPA and DHA, their n-3 PUFA status is higher than would be expected.
The study participants were recruited from the European Prospective Investigations into Cancer and Nutrition (EPIC)-Norfolk Study of 25,000 men and women. This study included 14,422 individuals in with 7-d food diaries and a sub-study of 4902 men and women in whom plasma phospholipid fatty acids were measured. Both the intakes and status of n-3 PUFA’s were measured. In addition, the precursor-product ratio of ALA to circulating n-3 PUFA’s was calculated.
The dominant source of EPA and DHA in the diet was fish, however for meat-eaters the major source was meat, and for vegetarians the major sources were spreading fats, soups, and sauces. Although the total intake of n-3 PUFA’s was 57-80% lower in non-fish eaters than fish eaters, the differences in n-3 PUFA status were considerably smaller. The estimated precursor-product ratio was greater in women than in men, and in non-fish eaters than in fish-eaters.
The authors conclude that the differences in n-3 status were smaller than would be expected given the substantial differences in intakes and sources of n-3 PUFA’s. They suggest that this may be because the precursor-product ratio was greater in non-fish eaters than fish-eaters, potentially indicating increased conversion of ALA. If these findings were confirmed through intervention studies, it could have implications on dietary requirements for fish.
Back to New research paper