Resveratrol supplements improve heart health

September 15, 2010

     Daily supplements of Resveratrol may improve vascular function and lead to improved cardiovascular health, according to new research.
The study evaluated the acute effects of Resveratrol supplementation on circulatory function, revealing that Resveratrol improves flow-mediated dilatation (FMD) - a marker of cardiovascular function. “Oral Resveratrol supplementation elicited an acute dose related improvement in endothelium-dependent vasodilatation, as demonstrated by significant increases in FMD at each dose relative to the placebo,” wrote the researchers, led by Dr Narelle Berry from the University of South Australia.

     Flow-mediated dilatation (opening of the artery for improved blood flow) of the brachial artery is a marker of blood vessel function and cardiovascular health, and is recognised as an independent risk factor for the development of cardiovascular diseases (CVD) if it is poor. Impaired FMD is associated with several cardiovascular risk factors including hypertension and obesity, and is characterised by structural and functional changes to the blood vessel endothelium (the active cells lining blood vessel walls that allow it widen or narrow in relation to the need for improved or lessened blood flow volume).
Various food ingredients, including polyphenols, and isoflavones, have been suggested to improve FMD.

     The cardiovascular benefits of Resveratrol - a polyphenol compound from Polygonum Cuspidatum and also from red wine - that have been suggested include enhanced antioxidant status, reduced inflammation, and increased NO availability; NO or nitric oxide is a gas released by healthy blood vessels that allows them to push open maintaining good circulation and normal blood pressure. A key mechanism behind blood vessel endothelial dysfunction involves impaired release of NO, causing blood vessels to constrict (squeeze). Increased availability of Resveratrol is suggested to increase NO production.

     This study investigated if oral supplementation of Resveratrol can enhance FMD, and assessing any potential dose-response relationship for this effect. The research compared supplements of 30, 90, and 270 mg Resveratrol with placebo in 19 overweight or obese subjects. The study revealed increasing doses of Resveratrol were associated with proportional increases in plasma Resveratrol concentrations. Resveratrol was also seen to significantly improve FMD compared to placebo.

     A significant linear relationship was found between Resveratrol dose and acute FMD responses. The higher the dosage of Resveratrol the better the flow of blood. “Whilst the FMD assessment does not reveal whether Resveratrol is acting on the endothelium or on vascular smooth muscle to enhance vasodilatation, there is evidence to suggest that Resveratrol can increase endothelium-derived NO bioavailability,” wrote the authors.
The researchers note their results suggest that Resveratrol could play a role in the reported cardiovascular health benefits of grapes and red wine.
The study is published online ahead of print in the journal Nutrition, Metabolism & Cardiovascular Diseases.