Beet juice does help with blood flow, and the evidence is stronger than for most dietary interventions. The key ingredient is dietary nitrate, which your body converts into nitric oxide, a molecule that relaxes and widens blood vessels. This effect is measurable: in people with high blood pressure, beet juice lowers systolic blood pressure by about 5 mmHg on average, and clinic measurements show reductions closer to 7.7 mmHg. The benefits extend beyond blood pressure to exercise performance, brain circulation, and walking ability in people with poor leg circulation.
How Beet Juice Opens Blood Vessels
The process starts in your mouth, not your stomach. When you drink beet juice, nitrate from the juice enters your bloodstream and then concentrates in your saliva. Bacteria living naturally on your tongue contain enzymes that convert this nitrate into a related compound called nitrite. You swallow the nitrite, it’s absorbed into your blood, and your body further converts it into nitric oxide through a chain of chemical reactions.
Nitric oxide signals the smooth muscle surrounding your blood vessels to relax, which widens both arteries and veins. This reduces resistance to blood flow throughout your body and allows your heart to pump blood more efficiently. The effect is especially strong in tissues that are low in oxygen, which is why beet juice seems to help most during physical exertion or in people whose circulation is already compromised. Humans lack the enzymes to make this nitrate-to-nitrite conversion on their own, so the oral bacteria are essential to the entire process.
Blood Pressure Effects
A meta-analysis in Frontiers in Nutrition looked specifically at people with high blood pressure and found that beet juice lowered systolic blood pressure (the top number) by about 5 mmHg across clinical and ambulatory measurements combined. Clinic-only readings showed a larger drop of roughly 7.7 mmHg. Diastolic pressure (the bottom number) showed smaller, less consistent changes of around 1 to 1.4 mmHg.
In a study of older adults with heart failure, one week of daily beet juice brought resting systolic blood pressure down from 134 to 120 mmHg. That’s a meaningful shift, comparable to what some blood pressure medications achieve. The nitrate dose in that study was about 6.1 millimoles, which is roughly what you’d get from a standard 70 mL concentrated beet juice shot sold for this purpose.
Exercise Performance and Oxygen Efficiency
Beet juice makes your muscles more efficient with oxygen. In one well-known finding, three days of supplementation reduced the oxygen cost of moderate-intensity exercise by about 15%. A separate analysis found that the oxygen needed per unit of work dropped by roughly 20%, a result researchers at the time called “remarkable” for a simple dietary change. Practically, this means your body does the same amount of work while burning less energy, which translates to longer endurance before fatigue sets in.
Time-to-exhaustion tests bear this out. In one trial, people drinking beet juice lasted 675 seconds compared to 583 seconds on a placebo, an improvement of about 16%. Another found that total distance covered during exhaustive exercise was roughly 50 meters greater in the beet juice group. Interestingly, these gains appear more pronounced in recreational exercisers than in highly trained athletes. One study found clear benefits in people with a moderate fitness level but little effect in those who were already very fit.
Brain Blood Flow in Older Adults
Beet juice increases blood flow to the brain’s frontal lobe, the region responsible for decision-making, attention, and working memory. Research has shown that just 24 hours on a high-nitrate diet supplemented with beet juice leads to increased regional blood flow in the brain’s white matter in older adults. Other studies have found that beet juice changes blood flow patterns in the prefrontal cortex during cognitive tasks, with some improvement in task performance. This is particularly relevant for aging, since reduced blood flow to the frontal lobe is associated with cognitive decline.
Walking Ability in Peripheral Artery Disease
People with peripheral artery disease have narrowed arteries in their legs, which causes cramping pain during walking. Beet juice helps here too. In one study, people with the condition could walk 18% longer before claudication pain began and lasted 17% longer overall. Another trial found that maximal walking distance increased by about 93 meters. A third showed that six-minute walking distance improved by roughly 37 meters compared to a placebo group, though pain-free walking distance didn’t change significantly.
These are not enormous distances, but for someone whose daily life is limited by leg pain after walking a block or two, an extra 90 meters of walking capacity is the difference between making it to the mailbox and making it around the block.
Timing and Dosage
Nitrite levels in your blood peak about 2 to 3 hours after drinking beet juice, and the measurable effects on performance appear around the 2.5-hour mark. If you’re drinking it before exercise, aim for about 2 to 3 hours beforehand.
Most positive studies have used doses containing 6 to 13 millimoles of nitrate. The lower end of that range (around 6 millimoles) is what’s found in a standard 70 mL concentrated beet juice shot, the kind sold at health food stores. Higher doses produce larger increases in blood nitrite levels. Some research suggests that very low doses (around 3 millimoles) raise nitrate levels in the blood but don’t produce measurable changes in oxygen use during exercise, so there does appear to be a minimum threshold.
Both single doses and multi-day protocols have shown benefits. Some effects, like reduced oxygen cost during exercise, appear after a single dose. Others, like the blood pressure reductions seen in heart failure patients, were measured after a full week of daily use. A moderate daily dose taken over several days to weeks appears to be a reasonable approach for sustained benefits.
One Thing That Blocks the Effect
Antibacterial mouthwash can neutralize the entire process. Because your oral bacteria are the only way your body converts nitrate to nitrite, killing those bacteria shuts down the pathway. In one study, using chlorhexidine mouthwash before consuming nitrate completely blocked the expected rise in plasma nitrite, even though saliva and plasma nitrate levels remained normal. In another trial, people with treated high blood pressure who used antibacterial mouthwash for three days saw their systolic blood pressure rise, essentially reversing the benefit that dietary nitrate would otherwise provide. If you’re drinking beet juice for its circulation benefits, avoid antibacterial mouthwash around the time of consumption.
Side Effects and Cautions
The most visible side effect is beeturia: pink or red urine that shows up in 10% to 14% of the general population after eating enough beets. The rate jumps to around 45% in people with pernicious anemia. It looks alarming but is considered benign. It can, however, be a signal of iron deficiency or absorption issues, so if it happens consistently, it’s worth noting.
A more serious concern involves kidney stones. Beet juice is high in oxalate, containing 60 to 70 mg per 100 mL. Oxalate binds with calcium to form calcium oxalate, the most common type of kidney stone. If you have a history of kidney stones, the amount of beet juice you consume matters significantly. Concentrated daily shots are a much smaller volume than glasses of juice, but the oxalate still adds up over time.