Flavonoid Supplementation and Endothelial Function

Overview

Flavonoids are one of the many classes of natural chemicals found in a variety of foods. People with the highest flavonoid blood levels have the lowest rates of coronary heart disease. This is considered one of the reasons why high fruit and vegetable consumption is associated with lower rates of heart disease, although it is not known if taking a flavonoid supplement provides the same protection as eating fruits and vegetables. The purpose of this study is to determine if a particular flavonoid supplement, called Isotonix OPC-3, taken on a daily basis, will improve the function of arterial vessels. Arteries normally constrict after eating a high-fat meal. This study will examine the potential of the OPC-3 to lessen this constriction response. Approximately 25 people will be involved in this research project and participation will last for 10 weeks.

We propose to use a supplement made by NutraMetrix (called OPC-3), consisting of oligomeric proanthocyanidins derived from grape seed, pine bark, bilberry, citrus and red wine extracts, to determine effects on endothelial function, lipoproteins and inflammation. The primary outcome measure will be endothelial function as assessed by digital response to hyperemia using peripheral arterial tonometry, measured both in the fasting state and after a single standardized high-fat meal, when transient dysfunction is expected to occur. Secondary outcome measures will be the lipid profile, hs-CRP, and Lp-PLA2. The recruitment population will be healthy volunteers. The design will be a randomized, placebo-controlled, double-blind, cross-over trial lasting 10 weeks.