Study Findings
A small randomized double-blind crossover study, published in Free Radical Biology and Medicine, linked beetroot juice consumption with reduced blood pressure in older adults. The study involved 78 participants, divided into younger (18-30) and older (67-79) age groups, who underwent three two-week trial periods.
Participants were instructed to drink either nitrate-rich beet juice or a placebo beet juice twice daily, or to rinse their mouths with mouthwash twice daily. The study aimed to analyze how bacterial changes within the oral microbiome might influence blood pressure levels. Participants were not medicated for cardiovascular or metabolic conditions and had no active oral disease.
After comparing the trials, researchers concluded that drinking beetroot juice may help lower blood pressure in older adults. No significant blood pressure-lowering effect was observed in the younger group.
Mechanism of Action
Cardiologist Padma Shenoy, M.D., suggested that the effect was likely due to changes in the composition of bacteria in the mouth. Elizabeth Adrian, R.D.N., explained that beet juice led to a decrease in bacteria like Prevotella and an increase in bacteria such as Neisseria and Rothia. These bacteria are more efficient at converting dietary nitrate into nitric oxide, a compound that aids in relaxing blood vessels.
Nitrates, found naturally in vegetables like beets, spinach, and arugula, are converted to nitric oxide with the help of oral bacteria. Nitric oxide can improve heart health by relaxing blood vessels and boosting blood flow. Nitrates are also components in some blood pressure-controlling medications. Naturally occurring nitrates in vegetables are considered safe for consumption, unlike those in processed foods or certain water sources.
Expert Interpretation and Recommendations
Dr. Shenoy noted that only older adults in the study experienced a slight reduction in blood pressure, and further studies are needed to identify which individuals will respond. She emphasized that while consuming vegetables like beetroot may support heart health, it represents only one aspect of a healthy lifestyle.
Recommendations for managing blood pressure and overall heart health include maintaining a varied diet, limiting sodium intake, and exercising regularly. These lifestyle choices, combined with personalized medical advice, are expected to have the most substantial impact on blood pressure and heart health.