By 2025, global prevalence of cardiovascular disease (CVD) is expected to be increased by 30%. Hypertension has remained as one of the major risk factors of CVD, as nearly 50% of all treated hypertensive patients are reported to have elevated blood pressure. Hence, effective but cost-effective alternative therapeutic strategies are in high demand, currently.
Several studies have indicated the elevated levels of circulating and tissue nitrite—a potent vasodilator in humans, post ingestion of dietary (inorganic) nitrate—via bioconversion in the entero-salivary circulation. Beetroot extract, being a rich source of nitrate has been evaluated clinically for its role in the management of hypertension.
A randomized, open-label, crossover study was performed in nine healthy subjects to investigate dose-dependent efficacy of beetroot juice-derived nitrate on systolic and diastolic blood pressure. In the trial, volunteers were provided with either 250 ml of beetroot juice (~5.5 mmol nitrate dose) or 250 ml of water.
Results suggested that compared to control group, swift increase in the plasma nitrate level was seen, which remained elevated over the 3-hour time course. As a result, systolic blood pressure was found to be decreased with a peak reduction of 5.4 mmHg.
Hence, it was concluded that an inverse relationship between systolic blood pressure and dietary nitrate supplementation exists. Additionally, it was also inferred that a dose-dependent decrease in blood pressure and vasoprotection, when inorganic nitrate in the form of dietary supplement was ingested (Kapil et al., 2010).
In another randomized, placebo-controlled clinical trial in 30 healthy subjects, a decrease in systolic blood pressure by 4–5 mmHg was observed at 6-hour interval after giving 500 g beetroot juice (=15 mmol/L nitrates). Blood pressure was measured every hour for 24 h.
And this 24 h study duration was further divided into active phase (where the individuals carried their routine physical activities) lasting for about 10 h and remaining hours were considered as passive phase (which included resting and sleeping time).
Study results showed that even during the active phase there was a significant reduction in systolic blood pressure when treated with beetroot juice (Coles and Clifton., 2012).
Adapted from: Coles and Clifton., Nutrition J. 2012