Beetroot is the swollen, bulb-shaped root of the plant Beta vulgaris, a member of the Amaranthaceae family. It’s the deep red vegetable you’ll find in grocery stores sold whole, canned, pickled, or pressed into juice. What makes it stand out nutritionally is its unusually high concentration of natural nitrates, pigments called betalains that give it that intense color, and a solid range of vitamins and minerals packed into relatively few calories.
What’s Actually in a Beetroot
A 100-gram serving of raw beetroot (roughly one small beet) contains about 43 calories and 5.1 grams of sugar, putting it on the sweeter side for a vegetable. When boiled, beets have a glycemic index of 64, classifying them as a medium-GI food. That’s higher than most vegetables but lower than white bread or rice, so the sugar content is rarely a concern for people eating whole beets as part of a balanced diet.
Beyond the basics, beetroot delivers folate (important for cell growth and especially relevant during pregnancy), potassium (which helps regulate fluid balance and blood pressure), and manganese (used in bone formation and metabolism). The fiber content is modest in juice form, around 0.9 grams per 100 mL, but eating the whole root gives you considerably more since juicing strips out the pulp.
How Beetroot Affects Blood Pressure
The headline benefit of beetroot comes from its nitrate content. When you eat beets, bacteria living on the back of your tongue convert the nitrates into a related compound called nitrite. From there, enzymes in your blood and tissues convert nitrite into nitric oxide, a molecule that relaxes and widens blood vessels. Wider blood vessels mean lower resistance, which means lower blood pressure.
This isn’t a small or theoretical effect. A meta-analysis published in Frontiers in Nutrition pooled results from clinical trials involving people with high blood pressure and found that beetroot juice lowered systolic blood pressure (the top number) by about 5 mmHg on average. That’s a meaningful reduction, roughly comparable to what some first-line blood pressure medications achieve. The effect on diastolic pressure (the bottom number) was smaller and not statistically significant in most analyses, dropping less than 1 mmHg on average. In clinic-based measurements, the systolic drop was even larger: about 7.7 mmHg.
The catch is that this effect depends on a continuous supply of dietary nitrate. Stop drinking the juice, and your blood pressure returns to its previous level. It’s a dietary strategy, not a cure.
Beetroot and Exercise Performance
The same nitrate-to-nitric-oxide pathway that lowers blood pressure also improves how efficiently your muscles use oxygen during exercise. When blood vessels dilate, more oxygen-rich blood reaches working muscles. Research has shown that beetroot supplementation can increase power output, delay time to exhaustion, and improve efficiency during both moderate and high-intensity exercise.
There’s an important nuance, though. Beetroot doesn’t appear to raise your VO2 max, which is the maximum amount of oxygen your body can use. One study found virtually identical VO2 max values after beetroot supplementation (51.1 ml/kg/min) compared to placebo (50.5 ml/kg/min). What changes is how efficiently you use the oxygen you already have. You can sustain the same effort while burning slightly less energy, which translates to lasting longer before you hit the wall. This makes beetroot particularly popular among endurance athletes: runners, cyclists, and rowers.
Juice, Powder, or Whole Beets
Not all beetroot products deliver the same dose of nitrate. A study that tested products marketed to athletes found dramatic differences. Powders contained the highest nitrate concentration, averaging 174 micromoles per gram. Concentrated juice shots came next at about 70 micromoles per milliliter. Bulk juices and mixed drinks trailed far behind at 13 to 18 micromoles per milliliter.
Absorption timing varies too. Some concentrated powder products peak in the bloodstream within 30 minutes of ingestion, while other beetroot juice supplements take 2 to 3 hours to reach peak levels. If you’re using beetroot to improve exercise performance, that timing matters. For general cardiovascular health, consistency over weeks matters more than precise timing on any given day.
Whole beets give you the added benefit of fiber and a broader range of nutrients, but they’re impractical if you’re trying to hit a specific nitrate dose before a workout. Most people who eat beets for general health are fine with whole roasted or steamed beets a few times a week. Athletes chasing a performance edge typically opt for concentrated juice shots or powders.
Side Effects Worth Knowing About
The most common and most harmless side effect of eating beets is beeturia: your urine turns pink or red. This happens in 10% to 14% of the general population, and the rate jumps to around 45% in people with certain types of anemia. It looks alarming the first time it happens, but it’s simply the betalain pigments passing through your system and carries no health risk.
Beetroot does contain oxalates, compounds that can contribute to kidney stone formation in susceptible people. If you’ve had calcium oxalate kidney stones in the past, large daily servings of beets or beet juice may not be the best choice. Eating beets alongside oxalate-rich foods like spinach or rhubarb can increase absorption of these compounds.
A Surprisingly Long History
Humans have been eating beet plants for thousands of years, though the root wasn’t always the main attraction. In the ancient world, people ate beet leaves and used the root mainly as medicine. The plant appears in a Greek translation of the Hebrew Bible from the third century BCE, and the first-century Roman naturalist Pliny described beet roots as less fleshy than a saffron crocus bulb, suggesting the swollen root we know today hadn’t yet been developed through selective breeding.
Ancient physicians recommended boiled beet root for burns, pustules, earaches, and dandruff. A fourth-century Babylonian rabbi named Hisda wrote that a fully cooked dish of beets was beneficial for the heart, the eyes, and the intestines. The Roman cookbook attributed to Apicius includes several beet recipes, including sliced beets with leeks, coriander, cumin, and raisin wine. The Greeks and Romans knew the plant well but never showed much enthusiasm for eating the root itself, preferring to use it sparingly as medicine. It took centuries of selective breeding to produce the sweet, bulbous root that fills modern produce aisles.