OPCs come out tops for heart health compared to other flavonoids
Cranberry juice rich in antioxidant proanthocyanidins is effective at boosting the health of blood vessels, thereby supporting previous research displaying the cardiovascular health benefits of such compounds. While the potential heart health benefits of flavonoid-rich diets have been reported previously, there was uncertainty about which constituents in flavonoid-rich foods may be behind the benefits, according to the British and Japanese researchers authoring the new study.
The findings published in the Journal of Agricultural and Food Chemistry indicate that Oligomeric Proanthocyanidins (OPC) had “by far the most potent effects” on the function of the endothelium (the cells lining blood vessels). The research also builds the science and understanding surrounding the consumption of cranberry juice. “Cranberry consumption is mostly studied in relation to the beneficial effects of A-type proanthocyanidins on urinary tract health,” explained the researchers. “However, when the anti-atherosclerotic actions of OPC are also considered, the daily consumption of cranberry juice is likely to have multiple health benefits.”
The researchers led by Professor Roger Corder at the Queen Mary University of London tested the effects of flavonoids on endothelial function. The in vitro tests focussed on measuring of synthesis of the vasoconstrictors endothelin-1 (ET-1).
Extracts of cranberry and cranberry juice along with apple, cocoa, red wine, and green tea showed that the OPC content determined the extent of inhibition of ET-1 synthesis, they said. Proanthocyanidin-rich extracts of cranberry juice were also found to produce changes in the morphology of endothelial cells that were independent of the compounds’ antioxidant activity. Most studies have shown a benefit of OPCs with doses in the range of 100 to 300 milligrams or more per day. Studies have suggested that OPC intake of an average diet is only about 25 mg per day. The study is published online ahead of print
Journal of Agricultural and Food Chemistry.