Beetroot Juice May Lower Blood Pressure in Older Adults
Nitrate-driven changes in the oral microbiome could explain the benefit
A University of Exeter study suggests that daily beetroot juice lowers blood pressure in adults over 60 by about 7 mm Hg. The effect is linked to dietary nitrate and its conversion to nitric oxide, which depends on healthy oral bacteria. Younger adults with normal blood pressure did not see the same benefit.
Study Details
Researchers conducted a placebo-controlled, double-blind crossover trial with 39 participants under 30 and 36 adults aged 60–70. Participants drank either nitrate-rich beetroot juice (750 mg nitrate) or a placebo version without nitrate for two weeks, separated by a two-week washout period.
Oral microbiomes were analyzed using gene sequencing, and participants also underwent a two-week trial of antiseptic mouthwash to evaluate microbial effects on nitrate metabolism.
Methodology
Design: Placebo-controlled, double-blind crossover
Population: Younger adults (<30 years) and older adults (60–70 years)
Intervention: 750 mg nitrate beetroot juice daily vs placebo juice
Assessment: Oral microbiome sequencing, blood pressure monitoring
Key Findings
The study found that baseline oral microbiomes did not differ by age, but in older adults, drinking nitrate-rich beetroot juice reduced harmful bacteria such as Prevotella and increased beneficial Neisseria, which improved the conversion of nitrate to nitrite. This microbial shift was linked to higher nitrite levels and better blood pressure control, with average readings in older adults dropping from about 126/80 mm Hg by roughly 7 mm Hg. No effect was observed in younger adults, likely because their blood pressure was already within normal range, and the placebo juice produced no impact in either group.
Implications for Practice
For adults over 60, nitrate-rich foods like beetroot juice, spinach, arugula, celery, fennel, and kale may help support blood pressure regulation. These findings highlight the role of the oral microbiome in cardiovascular health and suggest that antimicrobial mouthwash use could blunt these benefits.
For clinicians, this study points toward dietary strategies as a low-risk adjunct in managing hypertension in older adults, especially when patients prefer lifestyle interventions alongside medication.