Beetroot extract is a concentrated supplement derived from the common garden beetroot (Beta vulgaris), available as powders, capsules, or liquids. Rich in inorganic nitrates, beetroot extract has gained attention for its potential cardiovascular benefits, particularly blood pressure reduction. When consumed, dietary nitrates convert to nitric oxide, a signalling molecule that relaxes blood vessels and improves blood flow. Research has explored its effects on exercise performance, cognitive function, and heart health. Whilst beetroot extract is generally safe for most people, it should complement—not replace—prescribed medications and a balanced diet. This article examines the evidence, benefits, and safety considerations surrounding beetroot extract supplementation.

What Is Beetroot Extract and How Does It Work?

Beetroot extract is a concentrated form of the common garden beetroot (Beta vulgaris), typically available as a powder, capsule, or liquid supplement. The extract is derived from the root vegetable through processes such as juicing, drying, and concentration, which preserve its bioactive compounds whilst removing much of the water and fibre content. Beetroot has been consumed as a food for centuries, but its use as a concentrated supplement has gained considerable attention in recent years due to emerging research into its potential health effects.

The primary active compounds in beetroot extract are inorganic nitrates (NO₃⁻), which are naturally occurring nitrogen-oxygen compounds found in high concentrations in beetroot and other vegetables such as spinach and rocket. When consumed, dietary nitrates undergo a two-step conversion process in the body. First, bacteria in the mouth convert nitrates to nitrites (NO₂⁻), which are then further converted in the stomach and bloodstream to nitric oxide (NO), a crucial signalling molecule. Notably, using antibacterial mouthwash can disrupt this first conversion step and may reduce the effectiveness of beetroot extract.

Nitric oxide plays several important physiological roles, including:

• Vasodilation – relaxing and widening blood vessels, which may reduce blood pressure

• Improved blood flow – enhancing oxygen and nutrient delivery to tissues

• Mitochondrial efficiency – potentially improving cellular energy production

• Platelet function – influencing blood clotting mechanisms

Beetroot extract also contains other bioactive compounds, including betalains (pigments with antioxidant properties), polyphenols, and various vitamins and minerals. However, the nitrate content is considered the primary mechanism through which beetroot extract exerts its most studied effects. The concentration of nitrates in supplements varies considerably between products, though standardised extracts typically provide more consistent nitrate doses (approximately 4-8 mmol or 250-500 mg nitrate per serving) than would be obtained from eating whole beetroot as a vegetable.

Health Benefits of Beetroot Extract

Beetroot extract has been investigated for a range of potential health benefits, though the strength of evidence varies considerably across different applications. The most robust research focuses on cardiovascular health, particularly blood pressure regulation, but studies have also explored effects on exercise performance, cognitive function, and metabolic health.

Cardiovascular and blood pressure effects represent the most well-established area of benefit. Multiple systematic reviews and meta-analyses have demonstrated that beetroot extract supplementation can produce modest reductions in both systolic and diastolic blood pressure in various populations. This effect appears to be mediated primarily through the nitrate-nitric oxide pathway, which promotes vasodilation and improved endothelial function. The magnitude of blood pressure reduction is generally modest (typically around 4-5 mmHg systolic), but even small reductions at a population level can have meaningful impacts on cardiovascular risk. It's important to note that there is no evidence yet for reductions in long-term clinical outcomes such as heart attacks or strokes.

Exercise performance and endurance have also been extensively studied. Research suggests that beetroot extract may improve exercise efficiency by reducing the oxygen cost of physical activity, potentially enhancing endurance performance and time to exhaustion. This effect appears most pronounced in recreational athletes and those who are less trained, with more variable or limited benefits observed in elite athletes. The proposed mechanism involves improved mitochondrial efficiency and enhanced blood flow to working muscles.

Cognitive function is an emerging area of interest, with preliminary evidence suggesting that improved cerebral blood flow from nitrate supplementation might support brain health, particularly in older adults. However, this research is still in relatively early stages, and more robust clinical trials are needed.

Anti-inflammatory and antioxidant properties have been attributed to the betalain compounds in beetroot, though there is no official link established between beetroot extract supplementation and clinically significant anti-inflammatory effects in humans. Most evidence comes from laboratory and animal studies rather than well-designed human trials.

Evidence for Beetroot Extract in Blood Pressure and Heart Health

The cardiovascular benefits of beetroot extract, particularly for blood pressure management, have been examined in numerous clinical trials and systematic reviews. A 2013 meta-analysis published in the Journal of Nutrition analysed data from multiple randomised controlled trials and found that inorganic nitrate and beetroot juice supplementation significantly reduced systolic blood pressure by approximately 4–5 mmHg. Subsequent reviews have confirmed these findings, with effects typically observed within 2–3 hours of consumption and lasting up to 24 hours.

The mechanism underlying these blood pressure effects is well characterised. Dietary nitrates from beetroot extract are converted to nitric oxide, which activates soluble guanylate cyclase in vascular smooth muscle cells. This leads to increased cyclic GMP production, resulting in smooth muscle relaxation and vasodilation. This process effectively reduces peripheral vascular resistance, thereby lowering blood pressure. The effect appears to be dose-dependent, with higher nitrate doses generally producing greater blood pressure reductions.

Clinical significance and UK guidance: NICE guidance (NG136) on hypertension does not specifically recommend beetroot extract for blood pressure management. However, NICE does emphasise lifestyle modifications including a healthy diet with plenty of fruit and vegetables, reduced salt intake, weight management if overweight, regular physical activity, and limited alcohol consumption as part of comprehensive cardiovascular risk management. The blood pressure reductions observed with beetroot extract are comparable to those achieved through some dietary approaches.

Research has also explored beetroot extract's effects on endothelial function, a key marker of cardiovascular health. Some studies using flow-mediated dilation (a measure of endothelial function) have shown modest improvements following beetroot supplementation, suggesting potential benefits beyond simple blood pressure reduction. Additionally, some evidence indicates possible improvements in arterial stiffness, though these effects are not consistently demonstrated across all studies.

It is important to note that beetroot extract should not replace prescribed antihypertensive medications. Individuals with hypertension should continue their prescribed treatments and consult their GP before adding supplements. Beetroot extract might be considered as an adjunct to, rather than a replacement for, evidence-based medical management of cardiovascular conditions.

Safety, Side Effects and Who Should Avoid Beetroot Extract

Beetroot extract is generally considered safe for most people when consumed in typical supplemental doses (approximately 4-8 mmol or 250-500 mg of dietary nitrate). As a concentrated form of a common food vegetable, it has a long history of consumption without significant adverse effects. However, several considerations and potential side effects should be noted.

Common and harmless side effects include:

• Beeturia – pink or red discolouration of urine and occasionally stools, which is harmless and occurs in approximately 10–14% of people due to betalain pigments. This should not be confused with blood in urine or stools; persistent rectal bleeding, black tarry stools, or true haematuria require medical attention.

• Gastrointestinal symptoms – some individuals may experience mild stomach upset, bloating, or diarrhoea, particularly with higher doses

• Temporary throat irritation – occasionally reported with concentrated beetroot juice or powder

Important safety considerations and contraindications:

Individuals with kidney stones or a history of calcium oxalate stones should exercise caution, as beetroot is relatively high in oxalates, which can contribute to stone formation in susceptible individuals. Those with a history of kidney stones should consult their GP before using beetroot extract supplements.

People with chronic kidney disease should be cautious due to the potassium content in beetroot juice products, which could affect potassium levels, especially if taking potassium-sparing medications. People with diabetes should consider the sugar content of beetroot juices or shots.

People with low blood pressure (hypotension) should be cautious, as beetroot extract may further lower blood pressure. Symptoms of excessive blood pressure lowering might include dizziness, light-headedness, or fainting. Anyone experiencing these symptoms should discontinue use and seek medical advice.

Drug interactions are an important consideration. Beetroot extract may interact with medications including:

• Antihypertensive medications – potential for additive blood-pressure-lowering effects

• Nitrate medications (e.g., glyceryl trinitrate for angina) – risk of enhanced hypotensive effects

• Phosphodiesterase-5 inhibitors (e.g., sildenafil) – potential for significant additive hypotension

Patients taking any regular medications should consult their GP or pharmacist before starting beetroot extract supplementation.

It's worth noting that the European Food Safety Authority has established an Acceptable Daily Intake (ADI) for nitrate of 3.7 mg/kg body weight per day. When combining dietary sources with supplements, be mindful not to exceed this level chronically.

When to contact your GP: Seek medical advice if you experience persistent gastrointestinal symptoms, dizziness, unusual fatigue, or any concerning symptoms after starting beetroot extract. Individuals with existing cardiovascular conditions, kidney disease, or diabetes should discuss supplementation with their healthcare provider before use. Pregnant and breastfeeding women should consult their midwife or GP, as there is limited safety data for concentrated beetroot extract in these populations, although beetroot as a food is considered safe.

Food supplements should not be used as a substitute for a varied and balanced diet. If you suspect an adverse reaction to beetroot extract, report it through the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk).

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