Resveratrol Supplements Could Help Improve Heart Health
Lee Swanson Research Update
The study, published in Nutrition, Metabolism & Cardiovascular Diseases, is the first research to evaluate the acute effects of resveratrol supplementation on circulatory function, revealing that resveratrol improves flow-mediated dilation (FMD)—a marker of cardiovascular function.
"Oral resveratrol supplementation elicited an acute dose-related improvement in endothelium-dependent vasodilation, 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 Australia.
Flow-mediated dilation of the brachial artery is a marker of blood vessel function and cardiovascular health, and is recognized as an independent risk factor for the development of cardiovascular diseases (CVD).
Impaired FMD is associated with several cardiovascular risk factors including hypertension and obesity, and is characterized by structural and functional changes to the blood vessel endothelium.
Various food ingredients, including polyphenols and isoflavones, have been suggested to improve FMD. The cardiovascular health benefits of resveratrol—a polyphenol compound from red wine—have been suggested to include suppression of platelet aggregation, enhanced antioxidant status and increased nitric oxide (NO) availability.
A key mechanism behind blood vessel endothelial dysfunction is suggested to involve the impaired release of NO, causing blood vessels to constrict. Increased availability of resveratrol is suggested to increase NO production.
The current study investigated if oral supplementation of resveratrol can enhance FMD, and assessed 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.
Resveratrol supplementation increased blood plasma concentrations from 4.1 in placebo to 7.7 after 270 mg of resveratrol. A significant linear relationship was found between resveratrol dose and acute FMD response.
"Whilst the FMD assessment does not reveal whether resveratrol is acting on the endothelium or on vascular smooth muscle to enhance vasodilation, 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.
"Further research is warranted to confirm the sustainability of the effect of resveratrol on FMD," the researchers added.
Nutrition, Metabolism & Cardiovascular Diseases Published online ahead of print.
Sept. 2010