Drinking beetroot juice regularly can reduce the risk of heart disease and high blood pressure, a new study has found. Researchers at University of Guelph in Canada found that dietary nitrate, a compound found in beetroot juice that dilates blood vessels to decrease blood pressure, may reduce overstimulation of the sympathetic nervous system that occurs with heart disease. Activation of the sympathetic nervous system include elevated heart rate and blood pressure and blood vessel constriction. Sympathetic nerve activity (sympathetic outflow) also increases with some forms of cardiovascular disease, including high blood pressure and heart failure. Twenty young adult volunteers participated in two separate testing visits in which they blindly received either a nitrate supplement or a placebo. On both visits, researchers recorded the blood pressure, heart rate and muscle sympathetic nerve activity (MSNA) and measured muscle activity at rest and during handgrip exercise with the participants' non-dominant hand. Measurements were recorded at the beginning of the visit and then again after the volunteers drank nitrate-rich beetroot juice or a placebo and had rested on their backs for three hours. MSNA burst rate, denoting the frequency of nerve activity, was lower when the volunteers drank beetroot juice compared to when they drank the placebo.
Sympathetic nerve activity also decreased during exercise."Surprisingly, no differences in blood pressure were detected at rest or during exercise," researchers said. "These results provide proof-of-concept that dietary nitrate supplementation can modulate central sympathetic outflow and suggest that the established cardiovascular benefits of dietary nitrate are likely to involve a neural contribution," they said. The research was published in the journal Heart and Circulatory Physiology.