Beet

Beet (Beta vulgaris L.): A Comprehensive Reference

1. Identity: Botanical Classification, Chemical Names, and Natural Source

1.1 Taxonomy and Nomenclature

Beet, Beta vulgaris, is a plant included in the subfamily Betoideae of the family Amaranthaceae. It has several cultivar groups: the sugar beet, of greatest importance for producing table sugar; the root vegetable known as the beetroot or garden beet; the leaf vegetable known as chard or spinach beet; and mangelwurzel, a fodder crop. The beetroot is the taproot portion of a beet plant, usually known in Canada and the USA simply as "beets," while the vegetable is referred to as "beetroot" in British English. It is also known as the table beet, garden beet, red beet, dinner beet, or golden beet.

Three subspecies are typically recognized, but all cultivated beets fall into the subspecies Beta vulgaris subsp. vulgaris. The wild ancestor of the cultivated beets is the sea beet (Beta vulgaris subsp. maritima), and its center of origin lies in the Mediterranean region. The name Beta is the ancient Latin name for beetroot, possibly of Celtic origin, becoming bete in Old English.

Beta vulgaris (beet) is an herbaceous biennial or, rarely, perennial plant. Cultivated forms are mostly biennial. The plant is usually erect with a long main root and a rosette of leaves growing on stems. The roots of cultivated forms are dark red, white, or yellow, and moderately to strongly swollen and fleshy; or brown, fibrous, sometimes swollen and woody in the wild subspecies.

1.2 Common Forms and Preparations

There are 11 different varieties of Beta vulgaris L. that are used in the food industry, including sugar beets, beetroots, Swiss chard, and fodder beets. The deep red-colored beetroots are the most popular for human consumption, but this species comprises cultivars with bulb colors ranging from yellow to red.

As a dietary supplement and functional food, beet is commercially available in the following preparations:

• Fresh whole root: Consumed raw, roasted, boiled, or pickled.
• Beetroot juice (BRJ): Fresh-pressed or commercially bottled; the form used most extensively in clinical research. Regular (non-concentrated) beetroot juice typically provides approximately 250–500 ml (1–2 cups) per day, delivering roughly 200–500 mg of nitrate.
• Concentrated juice shots: One to two 70 ml concentrated shots per day is the form used in most research studies; concentrated shots deliver more nitrate in a smaller volume with less sugar.
• Dried powder: An analysis of 24 commercial products found nitrate ranging from 12–69 mg per fluid ounce in juices, 60–244 mg in concentrates, and 6–16 mg per gram of powder.
• Capsules and tablets: Dietary supplements in powder form generally contain higher doses of elements than those in capsule and tablet forms.
• Standardized extracts: Concentrated extracts standardized to betalain or nitrate content are also available commercially.

2. Traditional and Historical Use

2.1 Ancient Origins

The oldest archaeological evidence that beet was used in ancient times was found at the Neolithic site of Aartswoud in the Netherlands and in the Saqqara pyramid at Thebes, Egypt, which dates from the Third Dynasty (third millennium BC). Beetroot was domesticated in the ancient Middle East, primarily for its greens, and was grown by the ancient Egyptians, Greeks, and Romans; by the Roman era, it is thought they were also cultivated for their roots.

Humans originally ate beet greens but not the thin and fibrous roots, which were occasionally used in medicine. The large beet leaves and stalks were consumed like chard, a close relative. An Assyrian text of around 800 BC describes beetroot growing in the Hanging Gardens of Babylon, one of the seven wonders of the ancient world.

2.2 Greco-Roman Medicine and Culinary Use

The ancient Greeks and Romans ate the leaves and used these and the roots medicinally. Hippocrates bound wounds with beetroot leaves, and the plants were also used to treat fevers, skin conditions, and constipation. The physician Diphilus of Siphnus, who wrote about diet for both healthy and sick people around 300 BC, considered beets even better than cabbage for their health benefits. He prescribed them as a vermifuge and recommended eating beets boiled with mustard.

Romans ate roots mainly for medicinal purposes, using beet as a laxative or to cure fever. The Roman gourmet Apicius wrote a book called The Art of Cooking in which he gave recipes with beetroots, such as broths and salads with mustard, oil, and vinegar. The Romans also regarded beetroot as an aphrodisiac.

2.3 Medieval and Early Modern Europe

From the Middle Ages, beetroot was used to treat various conditions, especially illnesses relating to digestion and the blood. Bartolomeo Platina recommended taking beetroot with garlic to nullify the effects of "garlic-breath." The Romans used beets as a treatment for a number of ailments including constipation and fevers, and in the Middle Ages for illnesses involving digestion and blood. The root part of the beet was cultivated for consumption in either Germany or Italy, first recorded in 1542.

During the middle of the 17th century, wine was often colored with beetroot juice. Beet needed a few hundred years more to become popular in Central and Eastern Europe, where new cuisines with beetroot started appearing — borscht being a prominent example.

2.4 Arab Traditional Medicine

The beetroot (Beta vulgaris L.), locally known as Shamandar, is a vegetable plant belonging to the family Amaranthaceae. The roots of beet have long been used in traditional Arab medicine to treat a wide variety of diseases. The claimed therapeutic uses of beetroot include its antitumor, carminative, emmenagogue, hemostatic, and renal protective properties, and as a potential herb used in cardiovascular conditions.

3. Key Constituents and Active Compounds

3.1 Overview of Phytochemical Profile

Beetroot is rich in bioactive compounds, including betacyanin and betaxanthin, nitrates, phenolic and flavonoid compounds, saponins and triterpenoids, fatty acids, and amino acids. Beetroot is a rich source of nutrients including vitamins (B complex and C), minerals, fiber, proteins, and a variety of bioactive phenolic substances, which are chiefly composed of betalains, and other components possessing antioxidant activity, such as coumarins, carotenoids, sesquiterpenoids, triterpenes, and flavonoids (astragalin, tiliroside, rhamnocitrin, kaempferol, rhamnetin).

3.2 Betalains

Beetroot is one of the few plants that contain a class of extremely bioactive pigments known as betalains. Betalains are the main group of phenolic compounds in beetroot and can be subgrouped into yellow-orange betaxanthins and red-purple betacyanins. More than 80% of all the pigments in red beetroot are composed of betacyanins, mainly betanin and its isomer, whereas vulgaxanthin I represents the predominant betaxanthin (yellow pigment).

The betalains found in beetroot were identified as vulgaxanthin I, vulgaxanthin II, indicaxanthin, betanin, prebetanin, isobetanin, and neobetanin. The average value of betalains in red beetroot was calculated to be around 1,000 mg/100 g of total solids, or 120 mg/100 g fresh weight. Betalains and anthocyanins have never been found together in the same plant species.

3.3 Inorganic Nitrate

As a source of nitrate, beetroot ingestion provides a natural means of increasing in vivo nitric oxide (NO) availability, and has emerged as a potential strategy to prevent and manage pathologies associated with diminished NO bioavailability, notably hypertension and endothelial function. Even fresh beetroot varies considerably in its nitrate content, from 11–152 mg per 100 grams.

3.4 Polyphenols and Flavonoids

Beetroot also contains cyclodopa glucoside, N-formylcyclodopa glucoside, glucoside of dihydroxyindole carboxylic acid, betalamic acid, L-tryptophan, p-coumaric acid, ferulic acid, and traces of unidentified flavonoids, in addition to oxalic acid and ascorbic acid. Flavonoids such as apigenin, luteolin, kaempferol, and isorhamnetin demonstrate high gastrointestinal absorption and interact with multiple CYP isoforms, notably CYP1A2, CYP2D6, and CYP3A4, which may influence the pharmacokinetics of co-administered drugs.

3.5 Betaine and Other Compounds

Melatonin, an indoleamine with neuroregulatory roles, shows high blood-brain barrier permeability and CYP1A2 inhibition, while betaine, an osmolyte, exhibits low gastrointestinal absorption but may contribute to methylation and liver function regulation.

4. Mechanisms of Action

4.1 The Nitrate–Nitrite–Nitric Oxide Pathway

Nitrate and nitrite have previously been thought of as mainly final elimination products of nitric oxide (NO), but this view has been challenged and evidence indicates that these compounds can be converted to NO in vivo. In a process referred to as the enterosalivary nitrate circulation, or the nitrate–nitrite–NO pathway, dietary nitrate is swallowed and rapidly absorbed in the proximal gastrointestinal tract. In proportion to the dietary load of nitrate, approximately 25% of total circulating nitrate is actively sequestered into salivary glands and concentrated in saliva up to 20 times that in plasma.

Once ingested, the nitrate (NO₃⁻) is reduced to nitrite (NO₂⁻) by anaerobic bacteria in the oral cavity by the action of nitrate reductase enzymes, and then to nitric oxide (NO) in the stomach. This physiological mechanism depends on the entero-salivary circulation of inorganic nitrate without involving NOS activity. Once in the acidic stomach, nitrite is instantly decomposed to convert to NO and other nitrogen oxides performing determinant physiological functions. Nitrate and remaining nitrite are absorbed from the intestine into the circulation, which can become bioactive NO in tissues and blood under physiological hypoxia.

This oxygen-dependent enzymatic pathway involves three major NOS isoforms — neuronal NOS, inducible NOS, and endothelial NOS — each contributing to essential physiological functions such as vascular tone regulation, glucose uptake, and skeletal muscle blood flow. Recent evidence has identified an alternative, oxygen-independent nitrate–nitrite–NO pathway activated by dietary nitrate such as that obtained from beetroot juice.

Beetroot juice (BRJ), a concentrated dietary source of nitrate alongside betalains and polyphenols, influences physiology through enhanced nitrate–nitrite–NO bioavailability, antioxidant activity, and interactions with oral and gut nitrate-reducing microbiota. The efficiency of these mechanisms depends on dose, timing, and preservation of oral bacteria, with antibacterial mouthwash or thiocyanate-rich foods potentially blunting NO₂⁻ generation.

4.2 Antioxidant and Anti-inflammatory Mechanisms

The betalains (especially betanin) have received increasing attention for their effective biological activity. Betalains have been proven to eliminate oxidative and nitrative stress by scavenging DPPH radicals, preventing DNA damage, and reducing LDL. Betalain pigments in particular display potent antioxidant, anti-inflammatory, and chemo-preventive activity in vitro and in vivo.

NO plays a role in modulating inflammation, enhancing airway clearance, promoting bronchodilation, and inhibiting platelet aggregation, among other physiological functions. Dietary nitrate confers several cardiovascular beneficial effects on blood pressure, platelets, endothelial function, mitochondrial efficiency, and exercise.

4.3 Exercise Physiology Mechanisms

Beetroot juice increases levels of nitric oxide (NO), which serves multiple functions related to increased blood flow, gas exchange, mitochondrial biogenesis and efficiency, and strengthening of muscle contraction. After supplementation with beetroot juice, NO causes dilation of capillaries or small arteries, increases microcirculatory blood flow, improves the transport of tissue oxygen, nutrients, and metabolic wastes, accelerates the rate of lactic acid clearance, and allows for a more adequate supply of oxygen to the tissues, as well as mediating an increase in mitochondrial efficiency.

5. Scientific Evidence by Area of Use

5.1 Cardiovascular Health: Blood Pressure Reduction

Blood pressure reduction is among the most robustly studied effects of beetroot, with multiple meta-analyses of randomized clinical trials (RCTs) available.

Sixteen trials met the eligibility criteria for one systematic review and meta-analysis. All studies had a crossover design. The trials were conducted between 2006 and 2012 and included a total of 254 participants, with 7–30 participants per study. The duration of each intervention ranged from 2 hours to 15 days. Inorganic nitrate and beetroot juice consumption were associated with greater changes in systolic BP [−4.4 mmHg (95% CI: −5.9, −2.8); P < 0.001] than diastolic BP [−1.1 mmHg (95% CI: −2.2, 0.1); P = 0.06].

A later meta-analysis included 22 trials conducted between 2009 and 2017 with a total of 47 intervention and 43 control groups (N = 1,248 total participants). Overall, systolic blood pressure (−3.55 mmHg; 95% CI: −4.55, −2.54 mmHg) and diastolic blood pressure (−1.32 mmHg; 95% CI: −1.97, −0.68 mmHg) were significantly lower in the beetroot-supplemented groups.

The mean difference of systolic BP was larger between beetroot juice–supplemented and control groups in the longer than in the shorter (≥14 days compared with <14 days) study durations (−5.11 compared with −2.67 mmHg) and the highest compared with the lowest doses (500 compared with 70 and 140 mL/d) of beetroot juice (−4.78 compared with −2.37 mmHg). A positive correlation was observed between beetroot juice dose and the mean differences of blood pressures.

A weak effect size was observed in a meta-analysis of trials that used nitrate-depleted beetroot juice as a placebo compared with other interventions (−3.09 compared with −4.51 mmHg for systolic BP and −0.81 compared with −2.01 mmHg for diastolic BP). These results demonstrate the blood pressure-lowering effects of beetroot juice and highlight its potential nitrate-independent effects.

Limitations and mixed evidence: Analysis of 6 randomized trials (181 participants) revealed no significant reductions in systolic blood pressure, diastolic blood pressure, or resting heart rate following chronic isolated sodium nitrate supplementation (250–590 mg/d, ≥1 week). This finding underscores that the blood-pressure effects documented with beetroot juice as a whole may not be attributable to nitrate alone, and that other compounds in the whole food or juice matrix may be contributing.

5.2 Endothelial Function and Vascular Health

As a source of nitrate, beetroot ingestion provides a natural means of increasing in vivo nitric oxide availability and has emerged as a potential strategy to prevent and manage pathologies associated with diminished NO bioavailability, notably hypertension and endothelial function. Beetroot is also being considered as a promising therapeutic treatment in a range of clinical pathologies associated with oxidative stress and inflammation.

Research has provided evidence that nitrate-rich beetroot had an acute effect on circulating immune cells and platelets in older adults, owing to decreased blood monocyte–platelet aggregates and reduced blood CD11b-expressing granulocytes.

5.3 Athletic and Exercise Performance

This is one of the most extensively investigated areas of beetroot supplementation in clinical research.

The available results suggest that supplementation with beetroot juice can improve cardiorespiratory endurance in athletes by increasing efficiency, which improves performance at various distances, increases time to exhaustion at submaximal intensities, and may improve cardiorespiratory performance at anaerobic threshold intensities and maximum oxygen uptake (VO₂max).

It was evident that beetroot juice supplementation had an effect on oxygen cost and consumption during exercise by more efficient adenosine triphosphate (ATP) production in combination with lower ATP consumption. However, the effect appears to be dependent on dose and duration. The effect on exercise performance is conflicting; time to exhaustion appears to increase, but its effect on time-trial performance needs further elucidation.

Findings show that beetroot-derived nitrates can improve endurance, oxygen efficiency, muscular power, recovery, and cardiovascular function, particularly in recreationally active or moderately trained individuals. However, results are mixed in elite athletes, likely due to their already optimized nitric oxide utilization.

Results from an umbrella review indicated that beetroot juice supplementation produced a statistically significant improvement in VO₂max among healthy adults; however, the effect size remained below a meaningful threshold in some analyses. Research on endurance performance shows the most consistent improvements with beetroot juice supplementation, reflecting its influence on oxygen cost, exercise economy, and tolerance to prolonged or high-intensity exertion.

Beetroot juice, noted for its high nitrate content, consistently enhanced oxygen efficiency and submaximal endurance, although benefits in elite or sprint athletes were less evident.

In a randomized controlled trial with trained football players, acute beetroot juice supplementation significantly enhanced anaerobic performance, as evidenced by increased peak and mean power and reduced time to peak power during the 30-second Wingate test. While no changes were observed in muscle oxygenation during exercise, a significant improvement in post-exercise muscle oxygen saturation was noted. These results suggest that beetroot juice may facilitate recovery-related muscle oxygenation without altering exercise-phase oxygen dynamics.

5.4 Cognitive Function and Brain Health

Beetroot (Beta vulgaris), known for its cardiovascular and metabolic benefits, contains a distinctive combination of bioactive compounds including inorganic nitrate, betalains, and polyphenols. Together these constituents influence vascular function, oxidative stress, mitochondrial efficiency, inflammation, and the microbiota.

Preclinical data indicate that beetroot and its key constituents enhance antioxidant defences, support neuronal bioenergetics, and modulate cholinergic and inflammatory pathways. Human studies further suggest that nitrate-rich beetroot can improve cerebral blood flow and vascular responsiveness, and that higher intakes of plant-derived nitrate are associated with reduced cognitive decline.

Beets are a source of numerous bioactive compounds including betalain pigments, phenols, and saponins, and the bioactive compounds show neuroprotective properties due to their antioxidant activity (protecting cells against oxidative stress caused by the overaccumulation of reactive oxygen species), anti-inflammatory effects, and the ability to lower the activity of acetylcholinesterase. The most common pigment present in beetroot is betanin. Scientists have repeatedly demonstrated the antioxidant activity of this compound, which is capable of protecting the cell membrane of neurons against peroxidation.

Cognitive function is a crucial aspect of athletic performance, but evidence for cognitive benefits of nitrate-rich beetroot supplementation is limited and inconsistent. Clinical studies of beetroot report improvements in cerebral blood flow, inflammation, and in some cases cognition, but none have been conducted in Alzheimer's disease populations. The cognitive evidence base is therefore currently preliminary, and findings largely derive from mechanistic and short-duration human studies rather than long-term trials.

5.5 Antioxidant and Anti-inflammatory Activity

Beetroot is being considered as a promising therapeutic treatment in a range of clinical pathologies associated with oxidative stress and inflammation. The powerful antioxidant, anti-inflammatory, and vascular-protective effects offered by beetroot and its constituents have been clearly demonstrated by several in vitro and in vivo human and animal studies.

Betalains have been proven to eliminate oxidative and nitrative stress by scavenging DPPH, preventing DNA damage, and reducing LDL. Beetroot has also been found to exert antitumor activity by inhibiting cell proliferation, angiogenesis, inducing cell apoptosis, and autophagy. These findings are largely preclinical and in vitro; robust clinical evidence in cancer prevention is not yet established.

5.6 Glycemic and Metabolic Effects

Hyperglycemia is a condition for which the ingredients of betalains, polyphenols, and dietary nitrate in beetroot might provide benefit. It was found that with beetroot intake, the postprandial insulin response in the 0–60-minute phase and the glucose response in the 0–30-minute phase were significantly downregulated in healthy volunteers.

In some chronic diseases, nitrate is the main component for lowering blood lipids, glucose, and pressure, while its role in treating hypertension and hyperglycemia has not been clearly stated. The evidence in this domain is still preliminary and primarily from small, short-duration trials.

5.7 Chronic Obstructive Pulmonary Disease (COPD)

Beetroot juice is readily accessible and cost-effective, and is noted for its ability to enhance athletic performance and for its preventive and therapeutic impact on hypertension. Beetroot juice is a rich source of dietary nitrates and modulates physiological processes via the nitrate–nitrite–nitric oxide pathway, exerting multiple beneficial effects such as antihypertensive, bronchodilatory, anti-inflammatory, antioxidant, hypoglycemic, and lipid-lowering actions.

Several studies have demonstrated that the consumption of beetroot juice significantly elevates the concentration of plasma nitrates in patients with COPD. Beetroot juice, enriched with dietary nitrates, has multiple potential benefits for patients with COPD, yet this does not imply that more is necessarily better. The role of dietary nitrates in the human body is complex and can be likened to a double-edged sword. Clinical evidence in COPD remains limited and mixed; further large-scale trials are needed to establish clinical recommendations.

5.8 Liver and Kidney Protection

Findings from preclinical studies suggested that the reversal effect of beetroot against drug-induced liver or kidney toxicity is likely ascribed to its anti-inflammatory, antioxidant, and anti-apoptosis properties. Several lines of evidence have shown that betalains might reduce the risk of some cancers, cardiovascular and cerebrovascular diseases, liver, and kidney damage. This evidence is predominantly animal-based and in vitro; human clinical trials in this area are lacking.

6. Body Systems Associated with Beet

• Cardiovascular system: Blood pressure regulation, endothelial function, platelet aggregation inhibition, vascular tone modulation via nitric oxide.
• Musculoskeletal and exercise systems: Oxygen utilization, mitochondrial efficiency, ATP production, time to exhaustion, muscle recovery.
• Neurological/Cognitive system: Cerebral blood flow, neuroprotection, acetylcholinesterase inhibition, neuronal membrane protection.
• Metabolic system: Glucose metabolism, postprandial insulin response, lipid reduction.
• Respiratory system: Bronchodilation, oxygen delivery in hypoxic conditions, COPD management.
• Hepatic and renal systems: Antioxidant-mediated protection (primarily preclinical evidence).
• Gastrointestinal system: Historical use as a digestive aid; fiber content supporting gut transit.
• Oral microbiome: The nitrate–nitrite–nitric oxide pathway relies on oral bacteria to reduce nitrate to nitrite; nitric oxide generated from nitrite and L-arginine regulates vascular endothelial function and blood pressure.

7. Dosage Forms and Dosages Reported in Clinical Studies

7.1 Nitrate Dose

Most clinical trials have used approximately 300–500 mg of dietary nitrates as the effective dose, typically provided as 70–140 ml of concentrated beetroot juice (approximately 2–3 times the concentration of standard juice) or equivalent powder.

7.2 Concentrated Juice Shots

One common intervention uses an oral dose of nitrate-rich beetroot juice (70 mL Beet-IT Sport; James White Drinks, UK; containing 400 mg nitrate/70 mL) taken once daily, with the placebo being an identically packaged nitrate-depleted beetroot juice (identical drink and volume with nitrate content removed). Studies have also used twice-daily ingestion of 70 ml concentrated shots, each containing approximately 6.2 mmol NO₃⁻.

7.3 Standard Juice Volume

Drug-naïve hypertensive patients demonstrated a reduction in clinic, home, and ambulatory systolic blood pressure that persisted throughout the entire 4 weeks of daily single-dose BRJ (250 mL, 6 mmol NO₃⁻). The mean difference in systolic BP was larger with higher doses of beetroot juice — 500 mL/d produced a mean difference of −4.78 mmHg compared with −2.37 mmHg at lower doses (70 and 140 mL/d).

7.4 Timing

Consuming beetroot juice concentrate with approximately 6.2 mmol of nitrate two and a half hours prior to a cardiopulmonary exercise test leads to more efficient oxygen utilization and improvements in aerobic work capacity indicators. Peak plasma nitrite levels have been reported to occur approximately 2–3 hours post-ingestion in pharmacodynamic studies.

7.5 Duration of Use in Trials

Study durations in the major blood pressure meta-analysis ranged from 2 hours to 15 days. The findings indicated that dietary nitrate supplementation reduces oxygen consumption at submaximal exercise, and these effects can last for 15 days if supplementation is maintained.

8. Safety Considerations and Known Interactions

8.1 Beeturia

Beeturia — red or pink urine after consuming beetroot — occurs in roughly 10–14% of the population. It results from unmetabolized betacyanins, the pigment compounds responsible for beetroot's deep red color, being excreted in urine. The juice can cause beeturia and red-colored stools, which may make patients think they are bleeding or may mask true internal bleeding in clinical settings — a practical consideration when monitoring gastrointestinal symptoms in patients.

8.2 Oxalate Content and Kidney Stones

Beetroot is moderately high in oxalates, and elevated urinary oxalate excretion is a documented risk factor for calcium oxalate stone formation in genetically susceptible individuals. A 2019 dietary oxalate review confirmed that high-oxalate foods consistently increase urinary oxalate in stone formers — and beetroot falls into that category. People with a history of oxalate stones should limit or avoid beetroot, particularly in concentrated powder form.

Beetroot juice is high in oxalate; thus, its chronic consumption may increase kidney stone formation.

8.3 Interactions with Antihypertensive Medications

Beetroot has additive blood pressure-lowering effects when combined with ACE inhibitors, ARBs, calcium channel blockers, or diuretics. The combination can cause blood pressure to drop too low.

8.4 Interactions with PDE-5 Inhibitors and Nitrate Medications

Both beetroot and PDE-5 inhibitors like sildenafil (Viagra) act through nitric oxide pathways. Combining them can cause a severe drop in blood pressure.

8.5 Chronic Kidney Disease (CKD)

People with chronic kidney disease (stages 3–5) should consult their renal team due to beetroot's high potassium content, which may cause dangerous hyperkalaemia.

8.6 Mouthwash and the Nitrate Pathway

The efficiency of the nitrate–nitrite–NO pathway depends on dose, timing, and preservation of oral bacteria, with antibacterial mouthwash or thiocyanate-rich foods potentially blunting NO₂⁻ generation. Use of antibacterial oral rinses before or around the time of beetroot consumption has been shown to significantly reduce the conversion of nitrate to nitrite and thus diminish the anticipated physiological effect.

8.7 Potential Drug–Metabolizing Enzyme Interactions

Flavonoids such as apigenin, luteolin, kaempferol, and isorhamnetin demonstrate high gastrointestinal absorption and interact with multiple CYP isoforms (notably CYP1A2, CYP2D6, and CYP3A4), which may influence the pharmacokinetics of co-administered drugs. The clinical significance of these in vitro CYP interactions in humans consuming typical dietary quantities of beetroot has not been conclusively established.

8.8 General Tolerability

The most common side effects are beeturia and minor digestive complaints. A 2015 review of red beetroot supplementation found it generally safe, with side effects largely limited to beeturia and minor digestive complaints. Possible exacerbation of symptoms has been noted in individuals with inflammatory bowel disease or irritable bowel syndrome, and diarrhea in some individuals, particularly with high consumption. While beetroot juice has shown some beneficial effects in experimental models of ulcerative colitis, its high fiber content may worsen symptoms in acute flares.

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