Objective: Dietary intervention studies suggest that a daily fish meal can improve blood pressure (BP); however, such a dietary regimen might be difficult to sustain. The objective of the present study was to investigate whether salmon consumption three times per week improves BP during energy restriction in young adults.
Methods: In this 8-wk intervention, 324 subjects (20-40 y of age, body mass index 27.5-32.5kg/m(2), from Iceland, Spain, and Ireland) were randomized to one of four energy-restricted diets (-30% relative to estimated requirements): salmon (150g three times per week, resulting in a daily consumption of 2.1g of omega-3 long-chain polyunsaturated fatty acids [omega-3 LC-PUFAs]), cod (150g three times per week, 0.3g of omega-3 LC-PUFAs per day), fish oil capsules (1.3g of omega-3 LC-PUFAs per day), or control (sunflower oil capsules, no seafood). Body weight, diastolic BP (DBP), systolic BP (SBP), and docosahexaenoic acid (DHA) in erythrocyte membrane were measured at baseline and endpoint.
Results: Participants showed weight loss (-5.2+/-3.2kg, P<0.001) and decreases in SBP (-4.4+/-8.6 mmHg, P<0.001) and DBP (-4.1+/-7.4 mmHg, P<0.001) after the intervention. The salmon (B=-2.71, P=0.032) and fish oil (B=-2.48, P=0.044) groups had significantly lower endpoint DPB than the cod group, but not significantly different from control. Lower baseline DHA (percentage) in erythrocytes was associated with greater DBP reductions (B=0.576, P=0.017).
Conclusion: Salmon consumption three times per week can decrease DBP similar to fish oil and significantly more than lean fish during an 8-wk energy restriction in young overweight individuals. A lower DHA content in erythrocyte membrane at baseline, which might indentify infrequent fish eaters, is associated with a greater DBP reduction in the course of an 8-wk dietary intervention providing fatty seafood.
Trial registration: ClinicalTrials.gov NCT00315770.
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