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Featured Clinical Reviews

August 27, 2003

Vascular Effects of Cocoa Rich in Flavan-3-ols

Author Affiliations

Letters Section Editor: Stephen J. Lurie, MD, PhD, Senior Editor.

JAMA. 2003;290(8):1030-1031. doi:10.1001/jama.290.8.1030

To the Editor: In vitro studies have suggested that flavonoids may have specific vascular effects, but their mechanism of action has not been clarified.1 A subclass of flavonoids—flavan-3-ols and their oligomers (procyanidins)—are constituents of cocoa beans, which can be detected in human plasma after ingestion of cocoa.2 In turn, plant extracts rich in flavan-3-ols can increase the activity of nitric oxide synthase (NOS) in endothelial cells.3 Nitric oxide is an essential signaling molecule in vascular physiology. Nitric oxide bioactivity can be preserved in human plasma in a circulating pool via increases in a number of nitrosated compounds.4,5 Thus, it is possible that cocoa rich in flavan-3-ols may lead to improved endothelium-dependent dilation via an increase of nitric oxide bioactivity.

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