11. Beetroot
The nitrate king — blood pressure reduction via oral flora, with betalain on the kidney-stone gray zone.
Beetroot in 1 minute
What does it provide? Dietary nitrate (250–500 mg/100 g) → converted to nitrite by oral bacteria → NO, which is vasodilatory and BP-lowering. Plus pectin, betalains (antioxidant pigments), folate.
How much? ½–1 medium beetroot (≈ 100–150 g) steamed/roasted/in soup 3-4×/week; or 250–500 ml beetroot juice for acute BP effect (≈ 5–7 mmHg drop within 2-3 hours).[777]
When to avoid? Calcium oxalate kidney stone predisposition (oxalate ≈ 45–105 mg/100 g), active kidney stone, hypotension flare, when using antibacterial mouthwash (nitrate effect is abolished).
Beetroot was domesticated from the wild sea beet (B. vulgaris subsp. maritima) lineage along the Mediterranean coasts; it was already cultivated in ancient Egypt, Greece, and Rome — initially primarily for its leaves, as a chard-like vegetable, and only later for its swollen, sweet root. Classical authors such as Theophrastus and Pliny mention "Beta" uses in detail in their botanical and medicinal works; the Roman cuisine particularly favored it in Apicius's recipes, where it appeared together with honey, wine, and vinegar. In the Middle Ages it was used as medicine due to its red color and digestive effect, and in the 17th century it was even used to color wines.
The modern form of beetroot with its swollen root finally took shape in 16th–17th century Europe, and the 18th–19th centuries brought an industrial-history revolution within the species complex: Andreas Marggraf discovered in 1747 that sugar beet relatives contain sucrose, and his student Franz Karl Achard opened the world's first sugar beet factory in Silesia in 1801 — a revolution in industrial sugar history that reorganized all Western nutrition. Chard, the celery-stalk-like stem, fodder beet, and sugar beet all come from the same species complex. Today it is consumed worldwide in fresh, cooked, pickled, and fermented forms — particularly the Eastern European beet kvass.
Scientific Background
Beetroot has three distinct mechanisms: (1) Dietary nitrate–nitrite–NO pathway: ingested nitrate is reduced to nitrite by the oral microbiome (especially Veillonella, Actinomyces), which then converts to NO with gastric acid and in tissues. NO is vasodilatory, BP-lowering, endothelial-function-improving. (Webb 2008 classic RCT: 500 ml beetroot juice → -10/-8 mmHg within 2-3 hours.)[850] (2) Betalain antioxidants: the betacyanin (betanin, dark purple) and betaxanthin (yellowish) pigments have strong antioxidant + Nrf2-activating potential.[854] (3) Pectin fiber + polyphenols: colon fermentation, SCFA production.
The clinical BP effect is dose-dependent: 5–6 mmol nitrate (≈ 250 ml beetroot juice) is significant, 8–13 mmol gives a robust effect.[855] Meta-analyses (Siervo 2013) confirm an average -4.4 mmHg systolic reduction in hypertensives.[851] Sports performance: nitrate supplementation provides VO2 efficiency and endurance increase (Lansley 2011).[852]
Critical mechanism: if antibacterial mouthwash (chlorhexidine, Listerine) is used, the oral reducing bacteria are killed and the nitrate-BP effect is abolished (Govoni 2008).[853] The oxalate angle: beetroot is moderately high in oxalate, which is relevant for those prone to calcium oxalate kidney stones. Boiled-then-drained beetroot has 30-50% lower oxalate content.[856]
- + Calcium source (yogurt, kefir, feta): oxalate binding in the gut, reduced absorption.
- + Lemon + olive: classic Mediterranean dressing, betalain stabilization.
- + Apple cider vinegar + horseradish (classic Russian-Hungarian): color fixing, acidic medium.
- + Live cultures (beet kvass, fermented beetroot): synbiotic, more bioavailable.
- + Legumes (lentil-beetroot salad): fiber + GOS + nitrate combo.
- + Roasting in skin (110-120 min, 180 °C): caramelized, betalain-preserved.
- Antibacterial mouthwash (chlorhexidine, Listerine): nitrate-BP effect is abolished — DO NOT rinse around meals.
- Long boiling with discarded liquid: betalain loss, nitrate leaching.
- Iron supplementation + large polyphenol amount: time separation.
- Magnesium-containing antacid + large oxalate dose: theoretical kidney stone promoter.
- Hypotension-sensitive individuals + 500 ml juice at once: sudden BP drop, dizziness.
- PDE5 inhibitors (Viagra, Cialis) + high nitrate intake: NO synergy, excessive vasodilation.
- Calcium oxalate kidney stone predisposition: moderate consumption, boiled-drained form, with calcium accompaniment.
- Active kidney stone: avoid large dose.
- Severe hypotension: start with small dose, BP monitor.
- PDE5 inhibitor therapy: nitrate synergy contraindicated.
- Methemoglobinemia predisposition (rare): avoid large nitrate dose.
- Infant under 6 months: nitrate poisoning risk — clearly avoid.
- Acute gout flare: moderate purine, restraint.
- After beeturia (red urine) appearance: harmless phenomenon, but signals iron absorption decrease — worth checking iron status.
Daily/weekly serving
½–1 medium beetroot (≈ 100–150 g)/day in cooked/roasted/pickled form. For acute BP effect: 250–500 ml beetroot juice.
Preparation pattern
- Wash thoroughly, don't peel (cooks/roasts best in skin).
- Roasting in skin: at 180 °C for 60-90 min in foil — sweet, concentrated.
- Steaming: whole 30-45 min.
- Raw: grated on salad (lemon dressing).
- In juice: in blender + apple + ginger + lemon.
Classic patterns
Beet kvass (Polish-Ukrainian): raw beetroot + water + salt + starter, fermented 5-7 days at room temperature — synbiotic, nitrate-preserved.
Borscht (Ukrainian): beetroot soup with beef, potato, cabbage + sour cream.
Beetroot salad (Russian/Hungarian): grated roasted beetroot + horseradish + apple + walnut + olive.
Goat cheese + roasted beet salad: roasted beetroot + goat cheese + walnut + balsamic.
Hummus de remolacha: beetroot + chickpea + tahini + lemon + garlic — vibrant pink.
Storage
Fresh whole (in skin): refrigerated 2-3 weeks. Cooked: refrigerated 3-5 days. Kvass in jar refrigerated: 3-4 weeks. Frozen (roasted cubes): 8-10 months.
What not to do
Don't boil 30+ min uncovered (betalain loss, tasteless). Don't peel before cooking (juice runs out, bleeding texture). Don't rinse with antibacterial mouthwash before/after beetroot meals. Don't panic about beeturia (red urine).
References
[777] . Monash UniversityMonash FODMAP database. High and Low FODMAP foods. Link
The Monash University FODMAP database, classifying foods as high or low in FODMAP content.
[850] Webb AJ et al. Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite2008;51(3):784–790. Hypertension. Link
Diets rich in fruits and vegetables reduce blood pressure (BP) and the risk of adverse cardiovascular events. However, the mechanisms of this effect have not been elucidated. Certain vegetables possess a high nitrate content, and we hypothesized that this might represent a source of vasoprotective nitric oxide via bioactivation. In healthy volunteers, approximately 3 hours after ingestion of a dietary nitrate load (beetroot juice 500 mL), BP was substantially reduced (Delta(max) -10.4/8 mm Hg); an effect that correlated with peak increases in plasma nitrite concentration. The dietary nitrate load also prevented endothelial dysfunction induced by an acute ischemic insult in the human forearm and significantly attenuated ex vivo platelet aggregation in response to collagen and ADP. Interruption of the enterosalivary conversion of nitrate to nitrite (facilitated by bacterial anaerobes situated on the surface of the tongue) prevented the rise in plasma nitrite, blocked the decrease in BP, and abolished the inhibitory effects on platelet aggregation, confirming that these vasoprotective effects were attributable to the activity of nitrite converted from the ingested nitrate.
[851] Siervo M et al. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis2013;143(6):818–826. J Nutr. Link
Diets including food products rich in inorganic nitrate are associated with lower blood pressure (BP). The evidence for the BP-lowering effects of inorganic nitrate and beetroot in randomized clinical trials has not been systematically assessed. The objective was to conduct a systematic review and meta-analysis of randomized clinical trials that examined the effects of inorganic nitrate and beetroot supplementation on BP. Medline, EMBASE, and Scopus databases were searched from inception to February 2013. The specific inclusion criteria were: 1) randomized clinical trials; 2) trials reporting effects on systolic or diastolic BP or both; and 3) trials comparing inorganic nitrate or beetroot juice supplementation with placebo control groups. Random-effects models were used to assess the pooled BP effect sizes.
[852] Lansley KE et al. Acute dietary nitrate supplementation improves cycling time trial performance2011;43(6):1125–1131. Med Sci Sports Exerc. Link
PURPOSE: Dietary nitrate supplementation has been shown to reduce the O2 cost of submaximal exercise and to improve high-intensity exercise tolerance. However, it is presently unknown whether it may enhance performance during simulated competition. The present study investigated the effects of acute dietary nitrate supplementation on power output (PO), VO2, and performance during 4- and 16.1-km cycling time trials (TT). METHODS: After familiarization, nine club-level competitive male cyclists were assigned in a randomized, crossover design to consume 0.5 L of beetroot juice (BR; containing ∼ 6.2 mmol of nitrate) or 0.5 L of nitrate-depleted BR (placebo, PL; containing ∼ 0.0047 mmol of nitrate), ∼ 2.5 h before the completion of a 4- and a 16.1-km TT. RESULTS: BR supplementation elevated plasma [nitrite] (PL = 241 ± 125 vs BR = 575 ± 199 nM, P < 0.05). The VO2 values during the TT were not significantly different between the BR and PL conditions at any elapsed distance (P > 0.05), but BR significantly increased mean PO during the 4-km (PL = 279 ± 51 vs BR = 292 ± 44 W, P < 0.05) and 16.1-km TT (PL = 233 ± 43 vs BR = 247 ± 44 W, P < 0.01).
[853] Govoni M et al. The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash2008;19(4):333–337. Nitric Oxide. Link
Recent studies surprisingly show that dietary inorganic nitrate, abundant in vegetables, can be metabolized in vivo to form nitrite and then bioactive nitric oxide. A reduction in blood pressure was recently noted in healthy volunteers after dietary supplementation with nitrate; an effect consistent with formation of vasodilatory nitric oxide. Oral bacteria have been suggested to play a role in bioactivation of nitrate by first reducing it to the more reactive anion nitrite. In a cross-over designed study in seven healthy volunteers we examined the effects of a commercially available chlorhexidine-containing antibacterial mouthwash on salivary and plasma levels of nitrite measured after an oral intake of sodium nitrate (10mg/kg dissolved in water). In the control situation the salivary and plasma levels of nitrate and nitrite increased greatly after the nitrate load. Rinsing the mouth with the antibacterial mouthwash prior to the nitrate load had no effect on nitrate accumulation in saliva or plasma but abolished its conversion to nitrite in saliva and markedly attenuated the rise in plasma nitrite.
[854] Clifford T et al. The potential benefits of red beetroot supplementation in health and disease2015;7(4):2801–2822. Nutrients. Link
Review article (Nutrients) on the potential health and disease benefits of red beetroot supplementation.
[855] Hobbs DA et al. Acute ingestion of beetroot bread increases endothelium-independent vasodilation and lowers diastolic blood pressure in healthy men2013;143(9):1399–1405. J Nutr. Link
A human study on how acute ingestion of beetroot bread increases endothelium-independent vasodilation and lowers diastolic blood pressure in healthy men (J Nutr).
[856] Holmes RP et al. Dietary oxalate and the risk for nephrolithiasis 2004;15(12):3225–3232. J Am Soc Nephrol. 2004.
A study on dietary oxalate and the risk for nephrolithiasis (J Am Soc Nephrol).