Beetroot

Beetroot (Beta vulgaris) is the deep-red root vegetable, but as a supplement it matters for one reason: it is one of the richest dietary sources of inorganic NITRATE (NO3-). Sold as juice, powder, concentrated extract, or chews, beetroot is essentially a vehicle for getting nitrate into your body, where it is converted — via the nitrate-nitrite-nitric-oxide pathway — into nitric oxide (NO), a signalling molecule that relaxes and widens blood vessels. Everything beetroot is genuinely good for traces back to that nitrate-to-NO conversion; the betalain pigments that give beets their color are antioxidants and the source of beeturia (harmless red urine), but the nitrate is the performance-and-cardiovascular active.

The single most important thing to understand before buying is that the human trials dose by the amount of NITRATE — measured in millimoles (mmol) — and the endurance studies used roughly 6-13 mmol per dose. Yet almost no beetroot supplement discloses how much nitrate it contains. A label that reads '5 g of beet root powder' or '550 mg per capsule' tells you the beet MASS, not the nitrate load, and nitrate content varies widely with the beet cultivar, the soil it grew in, and how it was processed. The result: with most beet products you cannot verify whether you are reaching the studied dose. Concentrated extracts that standardize to a stated nitrate percentage are the rare exception that lets you reason about the dose at all; for everything else, beet mass is only a rough proxy.

Beetroot is not a one-serving miracle. The blood-pressure effect is most reliable when a moderate dose is taken consistently over weeks, and the endurance effect depends on hitting a meaningful nitrate dose in the hours before exercise. It is a food-derived, well-tolerated supplement — but it is best understood as a nitrate-delivery tool whose real-world value depends entirely on the dose and the consistency you can actually sustain.

The mechanism is the nitrate-nitrite-nitric-oxide (NO) pathway. After you ingest beetroot nitrate, bacteria on the tongue reduce some of it to nitrite; in the acidic, low-oxygen conditions of the stomach and in tissues, that nitrite is further converted to nitric oxide. NO is a vasodilator — it relaxes the smooth muscle in blood-vessel walls, widening them, improving blood flow, and lowering the pressure the heart pumps against. This single pathway explains both of beetroot's evidenced benefits.

For EXERCISE ENDURANCE, NO does two useful things: it improves blood flow to working muscle, and it appears to make muscle contraction more energetically efficient, lowering the oxygen cost of a given effort. Lansley 2011 (PMID 21071588) showed dietary nitrate reduced the O2 cost of both walking and running — the same pace required less oxygen. A companion Lansley 2011 trial (PMID 21471821) translated that physiology into performance: an acute nitrate dose improved 4-km and 16.1-km cycling time-trial times. Crucially, Wylie 2013 (PMID 23640589) established that DOSE matters: moderate (8.4 mmol) and high (16.8 mmol) nitrate doses raised time-to-exhaustion by ~14% and ~12%, while a low 4.2 mmol dose did not help at all. That dose-dependence is exactly why beetroot's near-universal failure to disclose nitrate is a genuine problem for anyone chasing the endurance benefit.

For BLOOD PRESSURE, the same vasodilation lowers the numbers directly. Webb 2008 (PMID 18250365) found that ~500 mL of beetroot juice reduced blood pressure by roughly 10/8 mmHg about three hours after ingestion, with the drop tracking the peak rise in plasma nitrite — pinning the effect on the nitrate-NO pathway. The Siervo 2013 meta-analysis (PMID 23596162) then pooled the randomized trials and confirmed a significant systolic reduction on the order of 4-5 mmHg across studies, establishing the blood-pressure effect as real and replicable rather than a single finding. The practical translation: the BP benefit rewards a moderate dose taken consistently, while the endurance benefit rewards a genuinely high nitrate dose timed before exercise.