Systematic review of the effect of omega-3 fatty acids on improvement of blood flow while focused on evaluation of claims for health functional food

Abstract

Omega-3 polyunsaturated fatty acids are essential fatty acids because humans cannot synthesize them de novo and must obtain them in their diet. Fish and fish oil are rich sources of omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Significant evidence of the beneficial role of dietary intake of omega-3 fatty acids in blood flow has been reported and putative mechanisms for improvement of blood flow include anti-thrombotic effects, lowered blood pressure, improved endothelial function, and anti-atherogenic effects. Edible oils containing omega-3 fatty acids were registered as functional ingredients in the Korea Health Functional Food Code. Although omega-3 fatty acids have been evaluated by the Korea Food and Drug Administration (KFDA) based on scientific evidence, periodic re-evaluation may be needed because emerging data related to omega-3 fatty acids have accumulated. Therefore, in this study, we re-evaluated scientific evidence for the effect of omega-3 fatty acids as a functional ingredient in health functional food on improvement of blood flow. A comprehensive literature search was conducted for collection of relevant human studies using the Medline and Cochrane, KISS, and IBIDS databases for the years 1955-2012. Search keywords were used by combination of terms related to omega-3 fatty acids and blood flow. The search was limited to human studies published in Korean, English, and Japanese. Using the KFDA’s evidence based evaluation system for scientific evaluation of health claims, 112 human studies were identified and reviewed in order to evaluate the strength of the evidence supporting a relation between omega-3 fatty acids and blood flow. Among 112 studies, significant effects on improvement of blood flow were reported in 84 studies and the daily intake amount was ranged from 0.1 to 15 g. According to this methodology of systematic review, we concluded that there was possible evidence to support a relation between omega-3 fatty acid intake and blood flow. However, because inconsistent results have recently been reported, future studies should be monitored.