Cocoa flavanols and brain perfusion

Abstract

Foods and beverages rich in flavonoids are being heralded as potential preventive agents for a range of pathologic conditions, ranging from hypertension to coronary heart disease to stroke and dementia. We and others have demonstrated that short-term ingestion of cocoa, particularly rich in the subclass of flavonoids known as flavanols, induced a consistent and striking peripheral vasodilation in healthy people, improving endothelial function in a nitric oxide-dependent manner. The vasodilator response was reversed by N-nitro-L-arginine methyl ester, an arginine analog that blocks nitric oxide synthesis. Flavanol-poor cocoa induced much smaller responses. Because impairment of endothelial function is a nearly universal accompaniment of the aging process, we examined the peripheral vasodilator response to flavanol-rich cocoa in healthy older subjects. Observations point to a favorable response among the older. Together with peripheral vascular disease, cerebrovascular disease is responsible for significant mortality with advancing age. An association of decreased cerebral perfusion with dementia has been recently highlighted. The prospect of increasing cerebral perfusion with cocoa flavanols is extremely promising. Our still preliminary data hold out the promise that the cerebral blood supply in the elderly participates in the vasodilator response. With the modalities of transcranial Doppler and MRI, we have the capabilities of analyzing the potential benefits of flavanols on brain perfusion and, subsequently, on cognition.