Beets

Beetroot

Beetroot (Beta vulgaris) is a root vegetable that over the past decade has become one of the most researched foods in the field of exercise physiology. The reason is not vitamins or minerals — but an especially high content of inorganic nitrates, and a fascinating biochemical pathway that they activate.

100 grams of raw beetroot provide about 43 calories, 10 grams of carbohydrates, 2.8 grams of fiber and about 250 mg of nitrate (the amount varies greatly depending on the soil and the variety).

The nitrate pathway — and why mouthwash ruins it

This is one of the most elegant metabolic pathways in nutrition, and understanding it explains all the practical recommendations.

1. Nitrate (NO₃⁻) from beetroot is absorbed in the gut and reaches the blood.
2. About 25% of it is secreted back into the salivary glands and concentrated there.
3. Anaerobic bacteria on the tongue — mainly at the back — reduce it to nitrite (NO₂⁻). Humans do not produce the necessary enzyme; we depend entirely on these bacteria.
4. The nitrite is swallowed, and in the acidic environment of the stomach and under low-oxygen conditions in the tissues it is converted into nitric oxide (NO).
5. NO is a powerful vasodilator, and it also improves mitochondrial efficiency.

The unusual practical conclusion: antibacterial mouthwash wipes out the tongue bacteria and cancels the effect almost completely. This has been demonstrated in trials — participants who rinsed with chlorhexidine showed no rise in NO and did not improve their performance. Anyone consuming beetroot for this purpose should avoid antiseptic mouthwash.

For a similar reason, avoid spitting after consuming beetroot — that is where the concentration happens.

Research-based health benefits

• Endurance performance — the best-established area: meta-analyses of controlled trials found improvements in time to exhaustion and in running/cycling economy with beetroot juice. The effect size is modest (on the order of 1-3%), but meaningful in a competitive context. The effect is more pronounced in recreational and intermediate athletes than in elite athletes, whose NO efficiency is already high. The mechanism: reducing the oxygen cost of exercise at a given intensity.

• Timing and dose: trials point to peak blood nitrite about 2-3 hours after consumption, at a dose of about 6-8 millimoles of nitrate (about 400-500 mg) — the amount found in about 500 ml of concentrated beetroot juice. Taking it for several consecutive days may be more effective than a single dose.

• Blood pressure: meta-analyses show a reduction of about 4-5 mmHg in systolic pressure with beetroot juice, mainly in people with high blood pressure. This is one of the most consistent findings.

• Betalains — unique antioxidants: the red-purple pigment is betanin, from the betalain family — a relatively rare group of antioxidants found almost only in beetroot and cacti. It is being studied for anti-inflammatory activity. Betalains are sensitive to heat and light, and prolonged cooking reduces them significantly.

• Fiber and the microbiome: 2.8 grams per 100 grams, including prebiotic fiber.

• Folate: 100 grams provide about 109 mcg — about 27% of the daily intake, an especially significant amount during pregnancy.

• Beet greens: almost always forgotten, but richer than the root in vitamin K, vitamin A, iron and lutein. You can use them like spinach or chard — they are close relatives.

Downsides and health considerations

• Beeturia: about 10-15% of the population pass reddish urine or stool after eating beetroot. The phenomenon is caused by betanin, it is completely harmless and depends on stomach acidity and genetics. Still, it is worth knowing: red urine that cannot be explained by beetroot requires medical evaluation — do not automatically assume it is beeturia.

• Oxalates: beetroot contains a relatively high amount of oxalates. For people prone to calcium oxalate kidney stones this is a real consideration, especially regarding concentrated beetroot juice consumed daily. Boiling in water reduces the content.

• Sugar content: beetroot is one of the sweetest vegetables (about 7 grams of sugar per 100 grams), and its glycemic index is moderate-to-high (about 64). However, its glycemic load is low thanks to the small amount actually eaten, and the fiber slows absorption. Beetroot juice, on the other hand, concentrates the sugar and removes the fiber.

• Nitrates and infants: nitrate-rich vegetables are not recommended for infants under 3-6 months of age because of the risk of methemoglobinemia (“blue baby syndrome”). At older ages there is no concern.

• The confusion about nitrates: a distinction is in order. Nitrates in vegetables come along with vitamin C and polyphenols that inhibit the formation of nitrosamines, and studies link them to beneficial effects. The nitrites added to processed meat act in a completely different context — alongside protein and amines, and under high heat — and that is where the concern about nitrosamines arises. Do not extrapolate from one to the other.

• Blood pressure medications: in combination with vasodilating drugs (especially medical nitrates or PDE-5 inhibitors) there may be an additive effect. Consult a professional.

Nutrition facts per 100 grams (raw)

Practical use

For performance: about 500 ml of beetroot juice (or a concentrated “shot”) about 2-3 hours before exercise. Avoid antibacterial mouthwash that day. It is better to try it out in training before using it in a race — beetroot may cause digestive discomfort in some people.

To preserve betalains: roasting in the oven in the skin, brief steaming or eating it raw (grated into a salad) are better than long boiling. Betanin is heat-sensitive and leaches into the cooking water.

To preserve nitrates: nitrate is water-soluble and leaches out during cooking. Roasting or baking preserves it better than boiling.

Pickled beets: pickling preserves most of the nitrates and adds lactic acid bacteria, but usually also a significant amount of sodium.

Don’t throw away the greens — they are the most vitamin-rich part of the vegetable.

Summary

Beetroot is one of the few cases in which a food has a defined, measurable mechanism of action established in controlled trials: the nitrate-nitrite-NO pathway, which improves oxygen efficiency during exercise and lowers blood pressure. The effect size is modest but real, and more pronounced in non-elite athletes. Two unique practical points that have no parallel in other foods: timing (2-3 hours before) and avoiding antibacterial mouthwash, which cancels the effect completely. The main caution is oxalates, mainly in daily concentrated juice.