Beetroot juice lowers blood pressure, improves exercise endurance, and increases blood flow to the brain. These effects come from its high concentration of natural nitrates, which your body converts into nitric oxide, a molecule that relaxes and widens blood vessels. A single 250 mL serving (about one cup) delivers enough nitrate to produce measurable changes in cardiovascular function within hours.
How Beetroot Juice Works in Your Body
The key ingredient in beetroot juice is inorganic nitrate. When you drink it, the nitrate is absorbed in your gut and distributed throughout your body, including back to your mouth. Bacteria on your tongue convert the nitrate into a related compound called nitrite. You swallow that nitrite, and when it hits the acidic environment of your stomach, it transforms into nitric oxide.
Nitric oxide enters your bloodstream and signals blood vessel walls to relax and expand. This is the mechanism behind nearly every benefit of beetroot juice: wider blood vessels mean lower blood pressure, more oxygen reaching your muscles during exercise, and better blood flow to your brain. It’s worth noting that mouthwash can actually blunt this process by killing the oral bacteria responsible for that first conversion step.
Blood Pressure Reduction
The most well-studied effect of beetroot juice is its ability to lower blood pressure. A meta-analysis of seven randomized controlled trials in people with high blood pressure found that beetroot juice reduced systolic blood pressure (the top number) by about 5 mmHg on average. In clinic-based measurements across five of those trials, the reduction was closer to 7.7 mmHg. The effect on diastolic pressure (the bottom number) was smaller and not statistically significant.
A 5 to 8 point drop in systolic pressure may sound modest, but at a population level, reductions of that size are associated with meaningful decreases in heart attack and stroke risk. The clinical dose used in most trials is about 250 mL of beetroot juice daily, delivering roughly 6.4 millimoles of nitrate. Research suggests 4 millimoles is the minimum threshold needed to see blood pressure changes in healthy people, though the ideal dose for people with hypertension isn’t fully pinned down.
Exercise Performance
Beetroot juice has become popular among endurance athletes for good reason. In trained cyclists, five days of supplementation reduced the amount of oxygen needed to sustain moderate-intensity effort by about 3%. That means the body works more efficiently at the same pace. In higher-intensity tests, time to exhaustion improved by as much as 16% when cyclists were working at 90% of their maximum capacity.
The performance gains show up in time trials too. Cyclists completed a 16.1 km course 2.7% faster and a 4 km course 2.8% faster after supplementing with beetroot juice. Their power-to-oxygen efficiency improved by 7% and 11% in those respective distances. For runners, the picture is more nuanced. In a 5,000-meter test, overall finishing times didn’t change significantly, but runners were 5% faster in the final stretch of the race, suggesting beetroot juice may help most when fatigue sets in.
Most exercise studies use acute supplementation periods of one to five days leading up to the activity. Nitrate levels in the blood typically peak two to three hours after drinking beetroot juice, so consuming it in that window before a workout or race is a reasonable approach.
Brain Blood Flow and Cognitive Function
The same blood vessel dilation that helps your heart and muscles also reaches your brain. In older adults, a high-nitrate diet supplemented with beetroot juice increased regional blood flow to the brain within 24 hours. The areas most affected include the frontal lobe, which handles decision-making, attention, and working memory.
Studies have shown that beetroot juice specifically increases blood flow to the prefrontal cortex during cognitive tasks, with some corresponding improvement in task performance. This line of research is particularly relevant for aging, since reduced cerebral blood flow is associated with cognitive decline. The idea is straightforward: more blood flow means more oxygen and glucose delivered to brain tissue when it’s working hard.
Antioxidant and Liver-Protective Effects
Beyond nitrates, beetroot juice contains pigments called betalains, which give beets their deep red color. These compounds have antioxidant properties and appear to support liver health. In lab studies using human liver cells, betanin (the primary betalain in beets) activated a protective signaling pathway that increased the production of several detoxification enzymes. These enzymes help neutralize harmful compounds before they can damage cells.
Animal studies have shown that beetroot juice protects against chemically induced liver injury, reinforcing the idea that betalains help the liver manage toxic exposure. While the human clinical evidence isn’t as robust as the blood pressure data, the antioxidant activity of beetroot juice is well documented and adds to its overall nutritional value.
Side Effects and Safety Concerns
The most common and completely harmless side effect is beeturia, a pink or red discoloration of your urine or stool after drinking beetroot juice. This happens in 10% to 14% of the general population and is more common in people who are iron deficient, where the rate climbs to around 45%. It can be startling if you’re not expecting it, and occasionally people mistake it for blood, but it’s nothing to worry about.
Beetroot juice is high in oxalates, with a half cup of beets containing about 76 mg. If you have a history of calcium oxalate kidney stones, regular consumption could increase your risk. This doesn’t mean you need to avoid it entirely, but it’s worth factoring into your overall oxalate intake.
Interactions With Medications
Because beetroot juice lowers blood pressure through nitric oxide pathways, it can interact with medications that work through similar mechanisms. If you’re already taking blood pressure medication, adding beetroot juice could amplify the effect and drop your pressure too low. Research in people with type 2 diabetes found that beetroot juice had little measurable impact on blood pressure or blood sugar when participants stayed on their existing medications, likely because the drugs were already working on the same pathways. When participants came off their medications, the effects of beetroot juice became more apparent.
The overlap with nitric oxide pathways also raises caution around nitroglycerin and medications for erectile dysfunction, which rely on the same signaling system. Combining these with a concentrated nitrate source could cause an unsafe drop in blood pressure. If you take any of these medications, it’s worth discussing beetroot juice with your prescriber before making it a regular habit.
How Much to Drink
Most clinical trials use 250 mL (about 8.5 ounces) of beetroot juice daily. Concentrated beetroot “shots” sold for athletic use typically come in 70 mL servings calibrated to deliver a similar nitrate dose in a smaller volume. For blood pressure benefits, daily consumption over at least one to two weeks appears to produce the most consistent results. For exercise, a loading period of three to five days before an event, with a final dose two to three hours before activity, aligns with the protocols that have shown the clearest performance gains.
Fresh-squeezed beetroot juice and commercial products vary in nitrate concentration, so standardized concentrated supplements offer more predictable dosing. Cooking beets reduces their nitrate content, which is one reason juice or raw preparations deliver stronger effects than roasted beets.