Consumption of salmon v. salmon oil capsules: effects on n-3 PUFA and selenium status

Salmon provides long-chain (LC) n-3 PUFA and Se, which are well recognised for their health benefits. The n-3 and Se status of the New Zealand population is marginal. The objective of the present study was to compare the effects of consuming salmon v. supplementation with salmon oil on LC n-3 and Se status. Healthy volunteers (n 44) were randomly assigned to one of four groups consuming 2 × 120 g servings of salmon/week or 2, 4 or 6 salmon oil capsules/d for 8 weeks. Linear regression analysis predictive models were fitted to the capsule data to predict changes in erythrocyte LC n-3 levels with intakes of LC n-3 from capsules in amounts equivalent to that consumed from salmon. Changes in Se status (plasma Se and whole-blood glutathione peroxidase) were compared between the groups consuming salmon and capsules (three groups combined). Salmon, 2, 4 and 6 capsules provided 0·82, 0·24, 0·47 and 0·69 g/d of LC n-3 fatty acids. Salmon provided 7 μg/d and capsules < 0·02 μg/d of Se. The predictive model (r(2) 0·31, P = 0·001) showed that increases in erythrocyte LC n-3 levels were similar when intakes of 0·82 g/d LC n-3 from salmon or capsules (1·92 (95 % CI 1·35, 2·49) v. 2·32 (95 % 1·76, 2·88) %) were consumed. Plasma Se increased significantly more with salmon than with capsules (12·2 (95 % CI 6·18, 18·12) v. 1·57 (95 % CI - 2·32, 5·45) μg/l, P = 0·01). LC n-3 status was similarly improved with consumption of salmon and capsules, while consuming salmon had the added benefit of increasing Se status. This is of particular relevance to the New Zealand population that has marginal LC n-3 and Se status.