Beetroot extract has gained considerable attention for its potential to increase nitric oxide levels in the body. This naturally occurring compound plays a vital role in cardiovascular health, regulating blood pressure, vascular function, and exercise performance. The mechanism centres on dietary nitrate found abundantly in beetroot, which the body converts through a well-established biochemical pathway into nitric oxide. Understanding how this process works, the supporting scientific evidence, and the practical considerations for supplementation can help individuals make informed decisions about incorporating beetroot extract into their health regimen. This article examines the evidence base, health benefits, dosing strategies, and important safety considerations surrounding beetroot extract and nitric oxide production.

How Beetroot Extract Affects Nitric Oxide Levels

Beetroot extract does increase nitric oxide levels in the body through a well-established biochemical pathway. The primary mechanism involves dietary nitrate (NO₃⁻), which is abundant in beetroot and other root vegetables. When consumed, nitrate is absorbed in the small intestine and enters the bloodstream, where a portion is actively taken up by salivary glands and concentrated in saliva.

In the oral cavity, commensal bacteria on the tongue surface reduce nitrate to nitrite (NO₂⁻) through the action of nitrate reductase enzymes. This nitrite is then swallowed and absorbed in the acidic environment of the stomach, or it enters the circulation directly. Once in the bloodstream and tissues, nitrite can be further reduced to nitric oxide (NO) through several enzymatic and non-enzymatic pathways, particularly in conditions of low oxygen availability or acidic pH.

This nitrate-nitrite-nitric oxide pathway represents an alternative route to endogenous nitric oxide production, which typically occurs through the enzymatic conversion of L-arginine by nitric oxide synthase (NOS) enzymes. The dietary nitrate pathway becomes particularly important when endogenous production is compromised, such as in cardiovascular disease or ageing. Nitric oxide is a crucial signalling molecule that regulates vascular tone, blood pressure, platelet function, and mitochondrial respiration.

The conversion efficiency depends on several factors, including:

• Oral bacterial flora – antiseptic mouthwashes (containing chlorhexidine or cetylpyridinium chloride) can significantly impair nitrate reduction

• Gastric pH – adequate stomach acidity facilitates nitrite conversion

• Individual metabolic variation – genetic and physiological differences affect response

• Concurrent medication use – some medications may theoretically influence conversion efficiency

Research consistently demonstrates that beetroot supplementation elevates plasma nitrite concentrations within 2–3 hours of consumption, with corresponding increases in nitric oxide bioavailability.

Scientific Evidence on Beetroot and Nitric Oxide Production

Substantial scientific evidence supports the role of beetroot extract in enhancing nitric oxide production. A systematic review and meta-analysis published in the Journal of Nutrition examined multiple randomised controlled trials and confirmed that beetroot juice supplementation significantly increases plasma nitrite concentrations, a reliable biomarker of nitric oxide bioavailability. Studies typically show peak plasma nitrite levels occurring 2–3 hours post-ingestion, with effects lasting 6–12 hours depending on dose.

Research conducted at UK institutions including the University of Exeter demonstrated that acute beetroot juice consumption (containing approximately 6–8 mmol of nitrate) elevated plasma nitrite by 100–300% compared to baseline values. These increases correlated with measurable improvements in endothelial function, assessed through flow-mediated dilatation of the brachial artery. The magnitude of response appears dose-dependent, with higher nitrate loads producing greater nitric oxide generation.

Key findings from clinical trials include:

• Beetroot supplementation reduces systolic blood pressure by 4–10 mmHg in some hypertensive individuals, with effects varying by population and baseline blood pressure

• Enhanced exercise performance and reduced oxygen cost during physical activity

• Improved cognitive function and cerebral blood flow in older adults

• Beneficial effects on endothelial function in patients with cardiovascular risk factors

A study published in Hypertension by Kapil et al. found that daily beetroot juice consumption produced reductions in blood pressure in hypertensive subjects. However, effects are generally modest and short-term, with greater responses typically seen in those with untreated or poorly controlled hypertension.

It is important to note that under GB Nutrition and Health Claims regulations, there are currently no authorised health claims for beetroot products or dietary nitrate in relation to blood pressure or cardiovascular function. Research from institutions including King's College London and Queen Mary University of London continues to investigate optimal dosing strategies and individual variability in response to beetroot-derived nitrate supplementation.

Health Benefits of Increased Nitric Oxide from Beetroot

The elevation of nitric oxide through beetroot consumption confers several evidence-based health benefits, primarily related to cardiovascular and metabolic function. Cardiovascular health represents the most extensively studied area, with nitric oxide playing a fundamental role in maintaining vascular homeostasis. As a vasodilator, nitric oxide relaxes smooth muscle in blood vessel walls, reducing peripheral vascular resistance and lowering blood pressure. Clinical trials demonstrate that beetroot supplementation can reduce blood pressure in individuals with hypertension, though effects are generally modest and short-term.

Beyond blood pressure regulation, increased nitric oxide bioavailability improves endothelial function – the ability of blood vessels to dilate appropriately in response to physiological stimuli. Endothelial dysfunction is an early marker of atherosclerosis and cardiovascular disease risk. Studies show that beetroot extract enhances flow-mediated dilatation, indicating improved endothelial health.

Exercise performance and recovery benefit from beetroot-derived nitric oxide through multiple mechanisms. Enhanced blood flow improves oxygen and nutrient delivery to working muscles, whilst nitric oxide also improves mitochondrial efficiency, reducing the oxygen cost of exercise. Research demonstrates improvements in time-to-exhaustion, time-trial performance, and high-intensity intermittent exercise capacity following beetroot supplementation, particularly in recreational athletes.

Cognitive function may also improve, as nitric oxide regulates cerebral blood flow. Studies in older adults suggest that beetroot juice increases perfusion to frontal lobe regions involved in executive function and working memory. However, cognitive benefits require further investigation to establish clinical significance.

Other potential benefits include improved glucose metabolism and insulin sensitivity, though evidence remains preliminary. Patients with type 2 diabetes or metabolic syndrome may experience modest improvements in glycaemic control, possibly through enhanced skeletal muscle glucose uptake.

It is important to emphasise that beetroot extract should complement, not replace, evidence-based medical treatments for cardiovascular or metabolic conditions. If you have high blood pressure of 180/120 mmHg or higher, especially with symptoms such as chest pain, breathlessness or neurological symptoms, seek urgent medical care in line with NHS guidance.

Recommended Dosage and Forms of Beetroot Extract

Beetroot extract is available in several forms, each with distinct characteristics regarding nitrate content, bioavailability, and practical considerations. Beetroot juice represents the most extensively studied form in clinical trials, typically providing 6–8 mmol (approximately 400–500 mg) of nitrate per 70 ml serving. Concentrated beetroot shots are commercially available and offer convenience, though taste can be a limiting factor for some individuals.

Beetroot powder and capsules provide alternative delivery methods with improved shelf stability and palatability. These products concentrate beetroot through freeze-drying or spray-drying processes. However, nitrate concentrations vary considerably between products, and many supplements do not standardise or declare nitrate content. It's worth noting that many beetroot extract capsules may be nitrate-depleted due to processing methods. Consumers should seek products with independently verified nitrate content.

Dosage ranges used in clinical research include:

• Single dose studies: 6–8 mmol nitrate (approximately 400–500 mg), consumed 2–3 hours before desired effect

• Research on regular consumption: 6–12 mmol nitrate daily, typically divided into one or two doses

• Blood pressure studies: Minimum 6 mmol used in trials showing effects

• Exercise performance research: 6–8 mmol consumed 2–3 hours pre-exercise

It's important to note that the European Food Safety Authority (EFSA) has established an Acceptable Daily Intake (ADI) for nitrate of 3.7 mg/kg body weight per day. Higher doses used in some research studies may exceed this ADI, and the long-term safety of sustained high-dose supplementation requires further investigation. Discuss regular or high-dose use with a healthcare professional.

Whole beetroot consumption provides approximately 1–2 mmol nitrate per 100g. Cooking may reduce nitrate content, with boiling potentially causing greater losses than roasting or steaming.

Timing considerations are important for optimising nitric oxide production. Peak plasma nitrite concentrations occur 2–3 hours post-consumption, making this the optimal window for activities requiring enhanced blood flow. For consistent benefits, regular supplementation appears preferable to intermittent use.

When selecting beetroot products, prioritise those with verified nitrate content and third-party testing for contaminants. Individuals should consult healthcare professionals before commencing supplementation, particularly if taking medications or managing chronic conditions.

Safety Considerations and Potential Side Effects

Beetroot extract is generally well-tolerated with a favourable safety profile when consumed at recommended doses. However, several considerations warrant attention. The most common and benign effect is beeturia – pink or red discolouration of urine and occasionally stools – which occurs in a significant proportion of the population following beetroot consumption. This harmless phenomenon results from betalain pigments and does not indicate any pathological process, though it may cause unnecessary concern if individuals are unaware of this effect.

Gastrointestinal symptoms represent the most frequently reported adverse effects, including mild nausea, stomach discomfort, or diarrhoea, particularly with high doses or concentrated extracts consumed on an empty stomach. These effects are typically transient and can be minimised by consuming beetroot products with food or reducing the dose initially.

Important safety considerations include:

• Hypotension risk – individuals with already low blood pressure should exercise caution, as beetroot may cause excessive blood pressure reduction, potentially leading to dizziness or fainting

• Kidney stone history – beetroot contains oxalates, which may increase risk in susceptible individuals; those with calcium oxalate kidney stones should consult their GP before regular consumption

• Medication interactions – beetroot may potentiate the effects of antihypertensive medications and other blood pressure-lowering drugs, requiring dose adjustments under medical supervision

• High potassium content – beetroot is rich in potassium, which may be relevant for people with chronic kidney disease or those taking ACE inhibitors, ARBs, or potassium-sparing diuretics

• Infants and young children – NHS guidance advises limiting high-nitrate vegetables in children under 1 year of age; concentrated beetroot products are not recommended for young children

There is no official link between beetroot consumption and serious adverse events in healthy adults at typical supplementation doses. However, the Medicines and Healthcare products Regulatory Agency (MHRA) does not regulate food supplements with the same rigour as medicines, meaning product quality and nitrate content may vary.

When to contact your GP:

• Persistent gastrointestinal symptoms lasting beyond 48 hours

• Symptoms of hypotension (dizziness, fainting, extreme fatigue)

• Unexpected changes in medication effectiveness

• Any concerning symptoms following supplementation initiation

Pregnant and breastfeeding women should consult healthcare professionals before using concentrated beetroot extracts, as safety data in these populations is limited. Whilst dietary beetroot consumption is considered safe, high-dose supplementation has not been adequately studied in pregnancy. Individuals with diabetes should monitor blood glucose levels, as beetroot contains natural sugars that may affect glycaemic control, though the glycaemic index is relatively low.

If you experience any suspected adverse reactions to beetroot products, report them through the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

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