Post-prandial effects of a meal rich in long-chain omega-3 fatty acids on indicators of cardiovascular risk

Abstract

Introduction

Evidence from epidemiological studies indicates that the regular consumption of oily fish may be protective against the risk of cardiovascular disease. The benefits appear to be related to the content of long-chain omega-3 fatty acids (LC n-3 PUFA), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Current UK dietary guidelines therefore recommend the consumption of two portions of fish per week, one of which should be oily (1), which equates to 0.45g LC n-3 PUFA per day. Although there is limited information about intakes of EPA and DHA in Scotland, recent studies show that they are consistently below recommendations (2). Further review of the dietary intake data indicates that the consumption of oily fish is sporadic and inconsistent (3) despite attempts to promote regular intake. Several of the mechanisms involved in the development of cardiovascular disease (CVD) involve endothelial function. Post-prandial hyperlipidaemia has been linked to an increased risk of CVD (4), which is largely attributed to the transient (2-6 hour) decrease in endothelial function (5). Changes in endothelial function have also been shown to be associated with superoxide production (6), implicating oxidative stress as a possible mechanism for endothelial dysfunction. The long-term effects of LC n-3 PUFA on oxidative stress and inflammation are well established, however little is known about their immediate post-prandial effects. Identifying the possible benefits of consumption of a single meal rich in LC n-3 PUFA may provide a new perspective on which to promote dietary changes. The aim of this pilot project was therefore to identify post-prandial changes in markers of cardiovascular risk, assessed by measurement of arterial compliance, whole blood fatty acid profile, plasma glucose and insulin, markers of endothelial dysfunction, oxidative stress and antioxidant status in response a test meal naturally rich LC n-3 PUFA compared with a control meal.