Article Source: American Physiological Society (APS)

Abstract: Researchers at American Physiological Society have reported that dietary nitrate, a compound which dilates blood vessels to decrease blood pressure may reduce overstimulation of the sympathetic nervous system that occurs due to heart disease. The entire study was focused on beetroot juice, a source of dietary nitrate, so as to explore its potential as a treatment option for cardiovascular disease patients.

Complete Article:

Researchers at American Physiological Society have reported that dietary nitrate, a compound which dilates blood vessels to decrease blood pressure may reduce overstimulation of the sympathetic nervous system that occurs due to heart disease. The entire study was focused on beetroot juice, a source of dietary nitrate, so as to explore its potential as a treatment option for cardiovascular disease patients.

 The study has been published ahead of print in the American Journal of Physiology — Heart and Circulatory Physiology with the title ‘Acute beetroot juice supplementation on sympathetic nerve activity: A randomized, double-blind, placebo-controlled proof-of-concept study and is the first study to research the effects of nitrate supplementation on sympathetic nerve activity.

Activation of the sympathetic nervous system is caused by increased sympathetic nerve activity. Some of its symptoms include accelerated heart rate and blood pressure and blood vessel constriction. The other reasons for the increase in sympathetic nerve activity (sympathetic outflow) can be some forms of cardiovascular disease, including high blood pressure and heart failure.

The objective of the study as mentioned by the Canadian researchers’ team was to show that “acute nitrate supplementation using beetroot juice can decrease muscle sympathetic outflow at rest and during exercise.”

The study was carried on twenty young adult volunteers (average age – 27) who participated in two separate testing visits during which they blindly received either a nitrate supplement or a placebo. After both the visits, the research team 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.

It was found that MSNA burst rate decreased when the volunteers drank beetroot juice instead 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,” the research team noted. “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.”

Journal Reference:

Karambir Notay, Anthony V. Incognito, Philip J. Millar. Acute beetroot juice supplementation on sympathetic nerve activity: A randomized, double-blind, placebo-controlled proof-of-concept studyAmerican Journal of Physiology – Heart and Circulatory Physiology, 2017; ajpheart.00163.2017 DOI: 10.1152/ajpheart.00163.2017