Beetroot extract has emerged as a popular dietary supplement for cardiovascular health, particularly regarding blood pressure management. Rich in inorganic nitrates, beetroot extract is converted in the body to nitric oxide, a molecule that promotes blood vessel relaxation and may help lower blood pressure. Whilst research demonstrates modest reductions in blood pressure readings, typically 4–5 mmHg systolic, the clinical significance varies between individuals. This article examines the evidence for beetroot extract's effects on blood pressure, recommended dosages, safety considerations, and how it compares to standard antihypertensive treatments prescribed under NICE guidelines.

How Beetroot Extract Affects Blood Pressure

Beetroot extract has gained considerable attention in cardiovascular health research due to its high concentration of inorganic nitrate. When consumed, these nitrates undergo a sequential reduction process in the body, first converting to nitrite in the saliva through bacterial action, and subsequently to nitric oxide (NO) in the stomach and bloodstream. Nitric oxide is a crucial signalling molecule that plays a fundamental role in vascular health.

The mechanism by which beetroot extract may influence blood pressure centres on nitric oxide's ability to promote vasodilation — the relaxation and widening of blood vessels. When blood vessels dilate, peripheral vascular resistance decreases, allowing blood to flow more easily through the circulatory system. This reduction in resistance can lead to measurable decreases in both systolic and diastolic blood pressure readings. The effect typically begins within 2–3 hours of consumption and may persist for several hours.

Beyond acute vasodilation, regular consumption of beetroot extract may support endothelial function — the health of the inner lining of blood vessels. The endothelium naturally produces nitric oxide, but this capacity diminishes with age and cardiovascular disease. By providing an exogenous source of nitrate, beetroot extract may help compensate for reduced endogenous nitric oxide production.

It is important to note that whilst the physiological mechanism is well-established, the clinical significance of blood pressure reductions varies between individuals. Factors such as baseline blood pressure, dietary nitrate intake from other sources, oral bacteria composition, and concurrent medications all influence the magnitude of effect. The response appears most pronounced in individuals with elevated blood pressure rather than those with optimal readings. Notably, antiseptic mouthwashes can significantly reduce the effectiveness by disrupting the oral bacteria needed for nitrate conversion.

Clinical Evidence for Beetroot Extract and Hypertension

A substantial body of research has examined beetroot extract's effects on blood pressure, with varying degrees of clinical significance. A 2013 systematic review and meta-analysis published in the journal Hypertension analysed data from multiple randomised controlled trials and found that beetroot juice supplementation was associated with a significant reduction in blood pressure. The average decrease was approximately 4–5 mmHg systolic and 1–2 mmHg diastolic, with effects most notable in shorter-term studies.

Subsequent research has explored whether these effects translate to sustained benefits in individuals with diagnosed hypertension. A notable UK-based study published in Hypertension in 2015 investigated daily beetroot juice consumption in hypertensive patients over four weeks. Participants receiving beetroot juice (containing approximately 6.4 mmol or 400 mg of inorganic nitrate) demonstrated clinically meaningful blood pressure reductions compared to placebo, alongside improvements in endothelial function and arterial stiffness. However, the effect size was modest compared to standard antihypertensive medications.

More recent evidence suggests the response may be heterogeneous across populations. Some individuals, termed "non-responders," show minimal blood pressure changes despite adequate nitrate intake. This variability may relate to differences in oral microbiome composition, as certain bacteria are essential for converting nitrate to nitrite. Additionally, the use of antibacterial mouthwash can significantly diminish the blood pressure-lowering effect by disrupting this bacterial conversion.

Whilst the evidence supports a modest hypotensive effect, it is crucial to emphasise that beetroot extract should not be considered a replacement for prescribed antihypertensive therapy. The magnitude of blood pressure reduction, whilst statistically significant in research settings, is generally smaller than that achieved with first-line medications such as ACE inhibitors, calcium channel blockers, or thiazide diuretics. NICE guidelines (NG136) do not currently recommend beetroot extract as a standalone treatment for hypertension.

Recommended Dosage and Forms of Beetroot Extract

Beetroot extract is available in several formulations, each with different nitrate concentrations and bioavailability profiles. The most commonly studied form is concentrated beetroot juice, typically providing 300–500 mg of inorganic nitrate per serving (approximately 70 ml of concentrated juice or 250 ml of standard beetroot juice). This quantity roughly equates to the nitrate content of 200–300 g of fresh beetroot.

Beetroot powder and capsule supplements offer convenient alternatives, though nitrate content varies considerably between products. When selecting a supplement, it is essential to verify the stated nitrate content, as some products contain minimal active ingredient. Reputable manufacturers should provide clear labelling indicating nitrate concentration per serving. A typical effective dose ranges from 300–500 mg of dietary nitrate daily, though some studies have used higher amounts.

The timing of consumption may influence effectiveness. Research suggests that blood pressure-lowering effects peak approximately 2–3 hours post-consumption, corresponding with peak plasma nitrite concentrations. For sustained effects, daily consumption appears necessary, as benefits diminish within 24 hours of discontinuation.

It is worth noting that whole beetroot consumption provides additional nutritional benefits beyond nitrate content, including dietary fibre, folate, manganese, and potassium. However, achieving therapeutic nitrate levels through whole beetroot alone requires consuming substantial quantities (approximately 200–300 g daily), which may be impractical for many individuals. Concentrated extracts offer a more feasible approach to achieving research-supported nitrate intake.

Important considerations include avoiding antibacterial mouthwash, which can reduce nitrate-to-nitrite conversion. There is limited evidence suggesting that proton pump inhibitors (PPIs) might affect the conversion process by altering gastric pH, but this requires further research. It's important to remember that beetroot products are food supplements, not licensed medicines, and their nitrate content can vary widely. Individuals should consult their GP or pharmacist before starting supplementation, particularly if taking prescribed medications.

Safety Considerations and Potential Side Effects

Beetroot extract is generally well-tolerated, with a favourable safety profile in most individuals. However, several considerations warrant attention before commencing supplementation. The most common and benign side effect is beeturia — the excretion of red or pink-coloured urine following beetroot consumption. This harmless phenomenon occurs in approximately 10–14% of the population and results from the excretion of betalain pigments. Whilst alarming in appearance, beeturia poses no health risk and resolves once consumption ceases. Similarly, beetroot can cause red discolouration of stools, which is also harmless but may cause concern if not anticipated.

Some individuals experience mild gastrointestinal symptoms, including stomach upset, bloating, or diarrhoea, particularly when first introducing beetroot extract or consuming large quantities. Starting with smaller doses and gradually increasing intake may improve tolerance. The high fibre content in whole beetroot or beetroot powder can exacerbate these effects in sensitive individuals.

A more significant consideration involves oxalate content. Beetroot contains moderate to high levels of oxalates, compounds that can contribute to kidney stone formation in susceptible individuals. Those with a history of calcium oxalate kidney stones should exercise caution and discuss supplementation with their GP before proceeding. Adequate hydration and calcium intake may help mitigate oxalate absorption.

Beetroot also contains potassium, which may be relevant for people with chronic kidney disease or those taking medications that can increase potassium levels (such as ACE inhibitors, ARBs, or potassium-sparing diuretics). These individuals should consult their healthcare provider before using beetroot supplements.

Individuals should contact their GP if they experience dizziness, light-headedness, or symptoms of hypotension after starting beetroot extract, particularly if taking blood pressure medications. Those with diabetes should also monitor blood glucose levels, as beetroot contains natural sugars that may affect glycaemic control, though the impact is generally modest. Pregnant or breastfeeding women should consult a healthcare professional before using beetroot supplements due to limited safety data.

Seek urgent medical attention if you experience severe dizziness, fainting, or if your blood pressure readings are very high (≥180/120 mmHg), especially with chest pain, breathlessness, or neurological symptoms. If you experience any suspected side effects from beetroot products, report them through the MHRA Yellow Card scheme.

Comparing Beetroot Extract to Standard Blood Pressure Treatments

When evaluating beetroot extract against established antihypertensive therapies, it is essential to consider both efficacy and clinical context. First-line antihypertensive medications recommended by NICE — including ACE inhibitors, angiotensin receptor blockers (ARBs), calcium channel blockers, and thiazide-like diuretics — typically reduce blood pressure by 10–15 mmHg systolic and 5–10 mmHg diastolic. These reductions substantially exceed those observed with beetroot extract (approximately 4–5 mmHg systolic), representing a clinically meaningful difference in cardiovascular risk reduction.

The evidence base for conventional antihypertensives is robust, with decades of research demonstrating significant reductions in cardiovascular events, including stroke, myocardial infarction, and heart failure. Large-scale outcome trials have established that blood pressure reduction with these medications translates to tangible improvements in morbidity and mortality. In contrast, whilst beetroot extract shows promise in reducing blood pressure readings, there is currently no evidence from long-term outcome trials demonstrating that it prevents cardiovascular events.

However, beetroot extract may have a role in specific contexts. For individuals with blood pressure above ideal but below NICE treatment thresholds (clinic BP <140/90 mmHg or ambulatory/home BP <135/85 mmHg) who do not meet criteria for pharmacological treatment under current NICE guidelines (NG136), dietary interventions including beetroot extract might form part of a comprehensive lifestyle approach. Similarly, it may serve as an adjunct to medication in individuals whose blood pressure remains suboptimally controlled despite treatment, though this should only be undertaken with medical supervision.

The side effect profile differs markedly between approaches. Whilst antihypertensive medications can cause adverse effects such as cough (ACE inhibitors), ankle oedema (calcium channel blockers), or electrolyte disturbances (diuretics), beetroot extract's side effects are generally mild and self-limiting. This favourable tolerability may appeal to some individuals, though it does not compensate for reduced efficacy.

It is crucial to emphasise that individuals with diagnosed hypertension requiring treatment should not discontinue or reduce prescribed medications in favour of beetroot extract without explicit guidance from their GP or specialist. Such changes could result in inadequate blood pressure control and increased cardiovascular risk. Beetroot extract should be viewed as a potential complementary approach within a broader strategy encompassing dietary modification (particularly a diet rich in fruits and vegetables, with reduced salt), regular physical activity, weight management, alcohol moderation, and salt reduction — all evidence-based interventions recommended by NICE for blood pressure management.

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