The effects of long-chain omega-3 fish oils and multivitamins on cognitive and cardiovascular function: a randomized, controlled clinical trial

Abstract

Objective: Fish oils and multivitamins are two of the most commonly used dietary supplements. Fish oil use may reduce vascular risk factors associated with cognitive decline, thus providing benefits to both heart and brain health. Multivitamins may also have direct effects on brain function. The present study investigated the effects of fish oil, with and without the addition of a multivitamin, on cognitive and cardiovascular function.

Methods: In a randomized, placebo-controlled, double-blind fashion, 160 healthy adults aged 50-70 years were randomized to receive either 3 g of fish oil (240 mg eicosapentaenoic acid [EPA] + 240 mg docosahexaenoic acid [DHA]) with a multivitamin, 6 g of fish oil (480 mg EPA + 480 mg DHA) with a multivitamin, or 6 g of fish oil without a multivitamin or a placebo. Cognitive performance, brachial blood pressure, and aortic (central) blood pressure were measured at baseline, 6 weeks, and 16 weeks.

Results: Treatment allocation had no effect on the primary cognitive outcomes at endpoint. Absolute increases in the red blood cell omega-3/6 ratio were associated with improvements in spatial working memory. The group receiving 6 g fish oil without the multivitamin displayed a significant decrease in aortic pulse pressure and aortic augmentation pressure, two measures of aortic blood pressure and aortic stiffness.

Conclusions: Fish oil decreased aortic pulse pressure and augmentation pressure. Reductions in aortic blood pressure were not accompanied by consistent improvements in cognition.

Keywords: aortic stiffness; blood pressure; cognition; cognitive; fish oil; omega-3.