Beetroot juice contains dietary nitrates that convert to nitric oxide in your body, a compound that dilates blood vessels and potentially increases blood flow to the brain—but this mechanism has not yet been proven to prevent dementia in controlled human trials. The evidence for beetroot juice specifically is limited: observational studies suggest plant-derived nitrates associate with lower dementia-related mortality, yet the strongest human trial conducted so far found no difference in cognitive function or brain blood flow between beetroot juice and placebo in older adults. This gap between mechanism and proof matters because dementia care decisions rely on evidence, not theory. Below is what the current research actually shows, where it falls short, and what remains under investigation.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- The Biological Case for Beetroot Juice
- What Controlled Trials Have Found
- The Causation Problem
- The Source of Nitrate Matters
- What to Do While Research Continues
- Frequently Asked Questions
The Biological Case for Beetroot Juice
Beetroot juice contains dietary nitrates that convert to nitric oxide via oral bacteria, according to researchers at the University of Exeter. Nitric oxide dilates blood vessels, which in principle allows more oxygen to reach the brain. Brain imaging in older adults on high-nitrate diets does show increased blood flow to white matter—tissue vulnerable to dementia-related degeneration—suggesting a biological pathway exists.
However, increased blood flow alone has not been shown to prevent cognitive decline. The mechanism is necessary but not sufficient evidence that beetroot juice prevents dementia. Many compounds that dilate blood vessels or increase brain oxygen do not slow or stop cognitive loss.
What Controlled Trials Have Found
A 13-week randomized trial of 62 older adults with overweight or obesity tested three different doses of beetroot juice against placebo and found no improvements in cognitive function or brain blood flow on MRI scanning. This is the most direct test of beetroot juice's effect on brain function in humans, and it produced a null result.
In contrast, observational studies—which track people's diets and measure outcomes over time without assigning them to interventions—show that people with the highest plant nitrate intake have about 57% lower dementia-related mortality risk compared to those with the lowest intake, based on follow-up data from 9,149 Australian adults over 17 years. This disparity raises a critical question: Are plant nitrates protecting the brain, or are people who eat nitrate-rich vegetables (like leafy greens, beets, and cabbage) doing other things that protect their cognition?.
The Causation Problem
Observational studies cannot prove causation. People who eat plenty of nitrate-rich vegetables typically exercise more, have higher education levels, better access to healthcare, and eat higher-quality diets overall. Any of these factors—or a combination—could account for their lower dementia mortality risk.
Without randomly assigning people to beetroot juice or placebo and following them for years, researchers cannot separate the effect of nitrates from the effect of lifestyle choices. This is why the University of Exeter launched a clinical trial in 2022 with 60 participants to test whether beetroot juice affects cognition through changes to the oral microbiome—the bacteria in your mouth that convert nitrates to nitric oxide. Results are pending and will help clarify whether dietary nitrates alone can prevent cognitive decline.
The Source of Nitrate Matters
Not all nitrates deliver the same benefit. Processed meat nitrates showed no dementia protection and were associated with twice the dementia-related mortality risk compared to plant-derived nitrates, according to the Australian follow-up study.
This suggests that adding a beetroot juice supplement is not equivalent to eating a diet rich in leafy greens, whole grains, and vegetables—the compounds surrounding the nitrates appear to matter. If you are considering beetroot juice for brain health, the current evidence does not support it as a proven dementia preventive. The evidence for a plant-forward diet rich in vegetables is stronger and does not rely on a single supplement.
What to Do While Research Continues
Current clinical trials are testing whether beetroot juice or dietary nitrates can improve cognition or brain blood flow in older adults. If pending results from the University of Exeter and other trials show benefit, guidance may change.
For now, the practical takeaway is that a whole diet rich in vegetables—which naturally contain nitrates alongside fiber, antioxidants, and other protective compounds—has broader support in dementia research than beetroot juice alone. If you or a family member is concerned about cognitive decline, discuss diet, exercise, social engagement, sleep quality, and cardiovascular health with your doctor. These factors have stronger evidence behind them than beetroot juice specifically.
Frequently Asked Questions
Should I start drinking beetroot juice to prevent dementia?
Not based on current evidence. The strongest human trial found no benefit, and observational studies showing a link between plant nitrates and lower dementia mortality cannot prove the nitrates caused the effect. Discuss diet and brain health with your doctor instead.
Is beetroot juice harmful?
No, but it is not proven to prevent dementia. If you already enjoy beetroot juice, there is no evidence of harm. However, it should not replace proven lifestyle interventions like exercise, a varied diet, social engagement, and cardiovascular health management.
Why haven't researchers already proven whether beetroot juice works?
Clinical trials testing a single dietary intervention over long enough to detect dementia prevention are expensive and take years to complete. The University of Exeter's trial results are still pending. Observational studies are faster but cannot separate the effect of one nutrient from dozens of other lifestyle factors.
Can I get the same effect from eating beets instead of drinking the juice?
Possibly, but whole beets contain fiber and other compounds not in juice alone. A diet rich in vegetables (including beets) has stronger support in dementia research than beetroot juice as a supplement.
