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 α-linolenic acid to long-chain n-3 polyunsaturated fatty acids results from the EPIC-Norfolk cohort

Background Intakes of n-3 (omega 3) polyunsaturated tatty acids (PUFAs) are important for health Because fish is the major source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) non fish eaters may have suboptimal n-3 PUFA status although the Importance of the conversion of plant-derived alpha-linolenic acid (ALA) to EPA and DHA is debated Objective The objective was to determine intakes food sources and status of n-3 PUFAs according to dietary habit (fish-eaters and non-fish-eating meat eaters vegetarians or vegans) and estimated conversion between dietary ALA and circulating long chain n-3 PUFAs Design This study included 14 422 men and women aged 39-78 y horn the EPIC (European Prospective Investigation into Cancer and Nutrition) Norfolk cohort with 7 d diary data and a substudy in 4902 individuals with plasma phospholipid fatty acid measures Intakes and status of n-3 PUFAs were measured and the precursor-product ratio of ALA to circulating n-3 PUFAs was calculated Results Most of the dietary intake of EPA and DHA was supplied by fish however meat was the major source in me it-eaters and spreading fats soups and sauces were the major sources in vegetarians Total n-3 PUFA intakes were 57-80% lower in non-fish eaters than in fish eaters but status differences were considerably smaller The estimated precursor product ratio was greater in women than in men and greater in non fish-eaters than in fish-eaters Conclusions Substantial differences in intakes and in sources of n-3 PUFAs existed between the dietary habit groups but the differences in status were smaller than expected possibly because the precursor-product ratio was greater in non fish eaters than in fish eaters potentially indicating increased estimated conversion of ALA If intervention studies were to confirm these findings it could have implications for fish requirements Ant J Clin Nutt 2010 92 1040-51