A glass of beetroot juice -- a source of dietary nitrate -- could dramatically lower as well as reduce heart attack risk, a study has revealed.

Dietary nitrate is a compound that dilates blood vessels to decrease blood pressure, a leading factor for developing heart attack.The findings, published in the Journal of Physiology - Heart and Circulatory Physiology, showed that the supplement can reduce overstimulation of the sympathetic nervous system that occurs with heart disease and causes the heart to beat faster."The study found that acute nitrate supplementation using beetroot juice can decrease muscle sympathetic outflow at rest and during exercise," researchers from the University of Guelph in Canada were quoted by express.co.uk. 

In the study, the team investigated 20 young adult volunteers with the average age of 27, who took part in two tests where they received a nitrate supplement or a placebo.The 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.The results revealed that the MSNA was lower when the volunteers drank beetroot juice compared to when they drank the placebo.

"Surprisingly, no differences in blood pressure were detected at rest or during exercise," the researchers said."The study provides 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 noted.A previous study by researchers at the University of Exeter has showed that a daily dose of raw beetroot juice can enable people to exercise for up to 16 per cent longer.