A high single oral dose of turmeric extract (Curcuma longa L.) does not improve skeletal muscle microvascular reactivity in older subjects

Abstract

Increased production of reactive oxygen species reduces nitric oxide (NO) bioavailability and impairs vascular function with aging. Curcumin is a polyphenolic compound found in the rhizome of turmeric (Curcuma longa) with antioxidant properties. An increasing number of studies have demonstrated improvement in the vasodilatory response of conduit arteries following curcumin supplementation, which has been associated with increased NO production. However, less is known about the effects of curcumin on resistance vessels response. Therefore, the present study aimed to investigate the effects of a high single dose of turmeric extract on skeletal muscle microvascular reactivity and plasma concentrations of NO metabolites in older adults. Twenty-one older adults consumed 10 g of turmeric extract (CUR) or placebo (PLA) in a randomized, double-blind, and crossover design. Blood samples were drawn to assay NO metabolites (NO2− and NO3−), and changes in oxygen saturation parameters following arterial occlusion were used to evaluate microvascular reactivity. There were no significant changes in plasma concentrations of NO2− and NO3− as well the parameters of oxygen saturation were not affected after CUR. In conclusion, a high single dose of turmeric extract does not affect the plasma concentration of NO metabolites nor skeletal muscle microvascular reactivity in older adults.

Keywords

• Curcuma
• Plant foods
• Dietary supplements
• Microvascular responsiveness
• Aging