Beetroot Juice and Its Surprising Effect on Blood Pressure
Integrating beetroot juice into daily life could reveal an unexpected connection between oral bacteria and blood pressure as people age.
Research from the University of Exeter in the U.K. indicates that older adults consuming nitrate-rich beetroot juice twice daily for two weeks saw notable drops in blood pressure. Interestingly, younger participants didn’t experience this effect, even though both age groups had changes in their oral microbiome due to the juice.
This study, featured in the journal Free Radical Biology and Medicine, represents the largest examination of how dietary nitrates impact oral bacteria, nitric oxide levels, and blood vessel responses. Nitrates, found naturally in various vegetables, play a key role in body function. While beetroot is abundant in nitrates, other sources—like spinach, arugula, celery, and kale—are also beneficial.
A critical step in utilizing nitrates occurs before they enter the bloodstream. Specific mouth bacteria help convert these dietary nitrates into compounds that assist in producing nitric oxide, which is essential for proper blood vessel function and blood pressure regulation.
Changes in the balance of these oral bacteria can negatively affect this conversion process. The study found that beetroot juice enhanced the oral microbiome in older participants, seemingly supporting this conversion pathway.
In total, the study involved 39 younger adults and 36 seniors, all recruited through the NIHR Exeter Clinical Research Facility. The research, backed by Exeter’s Clinical Trials Unit, followed a structured two-phase program where participants consumed either nitrate-rich beetroot juice or a nitrate-free placebo. A washout period between the phases helped negate carryover effects.
Using genetic sequencing to analyze the mouth’s bacteria, researchers noted significant microbiome changes in both age groups after beetroot juice intake, but with varying results. Among older adults, there was a significant decrease in Prevotella bacteria, deemed potentially harmful, while beneficial bacteria like Neisseria increased.
Interestingly, the older group started with higher blood pressure values. After the nitrate-rich juice phase, their blood pressure decreased, a change not seen after the placebo phase or in younger individuals. This may explain why beetroot juice appears particularly helpful for older adults.
As we age, our bodies produce less nitric oxide, which could lead to impaired blood vessel function. Prof. Anni Vanhatalo from the study emphasizes the health benefits of a nitrate-rich diet for older individuals, who are more prone to high blood pressure and its related health risks. Encouraging a diet abundant in nitrate-rich vegetables could yield long-term advantages. Thankfully, if beetroot isn’t your favorite, there are plenty of other options like spinach and kale.
The research indicates that beetroot juice’s efficacy isn’t solely about its nutrients. It may also alter the tiny ecosystem in the mouth, enhancing nutrient absorption. Further studies continue to show that oral bacteria significantly influence how nitrates impact the body.
In another recent study, adults with hypertension demonstrated that four weeks of consuming nitrate-rich beetroot juice modified their oral microbiome, increasing Neisseria and decreasing Veillonella, with no notable shifts in their gut microbiome.
Another research program noted that while nitrate supplementation affected nitrate metabolism, it didn’t lead to sustained improvements in blood pressure, indicating that individual factors like health status, medications, and initial microbiome composition might play a role.
A pilot study earlier this year highlighted the mouth’s role in nitrate biology, finding that antiseptic mouthwash could hinder nitrate processing and nitric oxide production in the stomach, while dietary nitrate supplementation partly preserved beneficial microbial activity.
Concerns around anticavity mouthwashes have also been raised, with studies indicating some formulations may support beneficial oral bacteria while lowering blood pressure more effectively than standard antiseptics.
While animal studies cannot be directly applied to humans, they add to the evidence suggesting that oral bacteria significantly impact nitrate processing. Beyond cumulative effects, earlier research hints that beetroot juice might also lower blood pressure shortly after consumption. Notably, findings indicate that maximum blood pressure reductions typically occur two to three hours post-consumption, correlating with peak nitrite levels in the bloodstream.
Effects on blood vessels might persist for up to 24 hours, emphasizing the need for regular intake to secure long-term benefits. To maximize nitrate uptake, experts urge attention to how food is prepared, as boiling nitrate-rich vegetables can deplete these compounds significantly. Fresh consumption or light cooking methods help retain nitrate levels.
Prof. Andy Jones notes that the study demonstrates how nitrate-rich foods can lead to beneficial oral microbiome changes that might reduce inflammation and lower blood pressure in older adults, paving the way for more extensive research into lifestyle factors affecting dietary responses.
While these findings don’t advocate for replacing medications or other established blood pressure treatments, they do highlight that integrating nitrate-rich vegetables into one’s diet could complement a heart-healthy lifestyle, especially as we age.
This research indicates that future nutritional approaches may need to be more personalized. Even if two individuals consume similar nitrate-rich foods, their bodies might respond differently based on how their oral microbiomes process those nitrates.
