Betanin: An Encyclopedic Reference
1. Identity: Chemical Names, Botanical Source, and Physical Properties
Betanin — also designated beetroot red — is the principal red-violet pigment of the red beet and the most abundant naturally occurring betacyanin. Betanin (betanidin-5-O-β-glucoside) is the most common betacyanin in the plant kingdom. Its systematic chemical name reflects this glycosidic structure: the aglycone betanidin is glucosylated at the 5-O position. Betanin or phytolaccamin (C24H27N2O13), the water-soluble red pigment, occurs in the roots of beetroot, Beta vulgaris L.
Betanin belongs to the betalain class of pigments. Betalains are unique nitrogen-containing pigments found exclusively in families of the Caryophyllales order and some higher-order fungi, where they replace anthocyanin pigments. Within that class, betanin is a betacyanin. The betacyanins (reddish to violet) contain a cyclo-3,4-dihydroxyphenylalanine (cyclo-DOPA) residue, while the betaxanthins (yellow to orange) contain different amino acid or amine residues. Betanin exists as a glucoside that, upon hydrolysis, transforms into a sugar unit and betanidin.
Betacyanins display an absorption maximum at approximately 535–538 nm, while betaxanthins typically show highest absorption at the 460–480 nm range, depending on the molecular structure and type of solvent. The color of betanin depends on pH; between pH four and five, it is bright bluish-red, becoming blue-violet as the pH increases. Once the pH reaches alkaline levels, betanin degrades by hydrolysis, resulting in a yellow-brown color.
Betanin is the only betalain with approved food-colorant status. The most abundant betacyanin is betanin (betanidin 5-O-β-d-glucoside) and is the only pigment which is an approved natural colorant for the use in food products prescribed by the Food and Drug Administration (FDA) in the United States. According to the regulation on food additives, betanin is permitted quantum satis as a natural red food colorant (E162). Moreover, betanin is used as a colorant in cosmetics and pharmaceuticals.
2. Natural Sources and Occurrence
The primary commercial and dietary source of betanin is the cultivated red beet. In the Caryophyllales family, betalains are most commonly found in edible sources in red beet roots (Beta vulgaris L.). Betanin is usually obtained from the extract of beet juice; the concentration of betanin in red beet can reach 300–600 mg/kg.
Beet root is a rich source of a group of red and yellow pigments known as betalains, comprising red-violet betacyanins and yellow betaxanthins. Betanin (75–95%) is the major constituent of the red pigment. Betanin is accompanied in beetroot by isobetanin, neobetanin, and prebetanin, while the yellow fraction is dominated by vulgaxanthin I and II.
Other dietary sources of betanin and other betalains include the Opuntia cactus (prickly pear), Swiss chard, and the leaves of some strains of amaranth. Betalains are naturally occurring pigments sourced mainly from Beta vulgaris (beetroot), Hylocereus spp. (dragon fruit), Amaranthus spp., and Opuntia spp. Betalains are also found as water-soluble pigments in mushrooms of the genera Amanita, Hygrocybe, and Hygrophorus.
3. Common Forms and Preparations
The most common uses of betanin as a colorant are in coloring ice cream and powdered soft drink beverages; other uses are in some sugar confectionery. In the food industry, betanin degrades when subjected to light, heat, and oxygen; therefore, it is used in frozen products, products with short shelf life, and products sold in dry state.
As a dietary supplement, betanin is available as standardized betalain-rich concentrates (BRC) derived from red beet or from nitrate-depleted beetroot extracts — typically in capsule form. Studies have used both whole beetroot juice preparations and standardized betalain concentrate capsules (see Dosage section). Betanin-enriched extracts derived from plants, such as red beetroot and red prickly pear (Opuntia stricta), are used as a dietary supplement for health maintenance.
Stability is a significant formulation challenge. Betanin showed significant stability up to −30 °C and mild stability at chilling temperature. Because light-sensitive enzymes are involved in manufacturing, betanin is sensitive to both light and temperature. For analytical and research purposes, betanin can be purified by semi-preparative HPLC-LC/MS and identified by LC-ESI(+)-MS/MS as the pseudomolecular ion m/z 551.16.
4. Traditional and Historical Use
The medicinal and culinary history of betanin is inseparable from the history of its primary plant source, Beta vulgaris. The beet descended from the sea beet, B. maritima, a wild seashore plant growing around the Mediterranean and along the coasts of Europe and North Africa. The ancient Greeks and Romans cultivated beets primarily for their greens, which were consumed as a vegetable. It was not until the Middle Ages that root beets began to gain prominence, particularly in Europe.
Ancient Romans used beetroot as a treatment for fevers and constipation, amongst other ailments. Apicius in De re coquinaria gives five recipes for soups to be given as a laxative, three of which feature the root of beet. Hippocrates used leaves of beetroot for binding and dressing wounds, while the Talmud, written in the 4th and 5th century, advises eating beetroot, among other things, for longer life. Romans ate the roots but mainly for medicinal purposes.
Traditional use of the root includes antitumor, carminative, emmenagogue, and hemostatic properties. Beetroot has been used traditionally as an emmenagogue and in the treatment of fibroids, but clinical trial data are lacking.
Use of betanin and other betacyanins as food coloring has a long history in Europe. Central and Eastern European cuisines that evolved from the 17th century onwards, such as borscht (a Ukrainian/Eastern European beet soup), demonstrate the deep culinary entrenchment of the plant. In Victorian times, beetroot was used to bring color to an otherwise colorless diet and as a sweet ingredient in desserts.
It is important to note that historical traditions worked with whole beetroot preparations — juices, decoctions, raw and cooked root — not with isolated betanin. The pigment betanin itself was not chemically characterized until the modern era. Betalains were first isolated and their chemical structure discovered in 1960 at the University of Zurich.
5. Key Constituents and Chemical Relationship to Other Betalains
All betalains are based on a common scaffold, betalamic acid, which condenses with cyclo-DOPA derivatives, or with various amino acids and other amines, to form betacyanins or betaxanthins, respectively. Betalamic acid is a constituent of all betalains; the type of betalamic acid substituent determines the class.
In red beetroot, betanin comprises 75–95% of the major red pigment fraction. It is accompanied by structurally related betacyanins including isobetanin (the C-15 epimer of betanin), neobetanin, and prebetanin. Betalamic acid, derived directly from cleavage of betanin, is probably the key intermediate in all betalains.
Whole beetroot also contains other bioactive constituents — particularly dietary inorganic nitrate (NO3−), betaine (trimethylglycine), folate, vitamin C, manganese, and polyphenols — which are important to keep in mind when interpreting evidence from beetroot juice studies. Beta vulgaris L. has notable scientific interest because it is a rich source of nitrate (NO3−), a compound with advantageous cardiovascular health effects through the endogenous production of nitric oxide (NO). Studies relying on beetroot juice cannot always isolate betanin's specific contributions from those of co-occurring nitrate or other phytochemicals.
6. Established Mechanisms of Action
6.1 Antioxidant Activity
Several in vitro studies have confirmed the radical scavenging properties of betalains against ABTS+, lipoperoxyl, and DPPH−. After administration of betalains from Beta vulgaris, concentrations of the antioxidants superoxide dismutase (SOD) and glutathione (GSH) were optimized and the lipid peroxidation marker malondialdehyde (MDA) was markedly reduced.
A key pathway through which betanin exerts antioxidant activity is the Nrf2-Keap1-ARE axis. Altered Nrf2-Keap1-ARE (Nuclear factor erythroid-2-related factor 2-Kelch-like ECH-associated protein 1-Antioxidant responsive element) and SIRT1 (Sirtuin 1) cell signaling pathways are considered to play a major role in the etiology and pathogenesis of Alzheimer's disease (AD) and Parkinson's disease (PD). Betanin, a betanidin 5-O-β-D-glucoside compound, is reported to show commendable anti-oxidative, anti-inflammatory, and anti-apoptotic effects in several disease studies.
Half of the betanin amount was recovered in the small intestinal digestive fluid, and no traces were found after colon fermentation. Betanin's high antioxidant ability was retained even after simulated small intestine digestion.
6.2 Anti-inflammatory Mechanisms
Some of the biological effects exhibited by betanin are underlined by two redox-sensitive pathways: the nuclear factor kappa B (NF-κB) and the nuclear factor erythroid-2-related factor — antioxidant response element (Nrf2-ARE), the main gene transcribers for inflammatory and detoxifying/antioxidant responses. Inhibition of NF-κB reduces downstream production of pro-inflammatory cytokines such as TNF-α and interleukin-6.
Betanin was also capable of modulating ROS generation and gene expression to activate antioxidant enzymes and reduce cytokine release, preventing endothelial damage and atherogenesis.
6.3 Anticancer Mechanisms (Preclinical)
Recent studies have shown that betalains exhibit anticancer properties and are being investigated for their potential use in cancer treatment. A well-known example is betanin, a natural dye belonging to the betalain group. It is related to the induction of cancer cell apoptosis targeting mitochondria, inducing the activation of caspases and the promotion of DNA fragmentation in cancer cells while sparing normal cells.
Results from cell-based studies have shown that betanin can inhibit cell viability, mitochondrial membrane potential, and inflammation, and can enhance apoptosis via the expression of NF-κB/PI3K/Akt pathways. These findings are entirely preclinical (in vitro).
6.4 Neuroprotective Mechanisms (Preclinical)
Betalains, particularly betanin and indicaxanthin, exhibit potent antioxidant and anti-inflammatory effects, targeting key mechanisms like ROS reduction, pro-inflammatory cytokine suppression, and the modulation of apoptosis-related pathways. Preclinical studies highlight their neuroprotective potential in Parkinson's disease (PD) by improving dopaminergic neuron survival and in Alzheimer's disease (AD) by reducing Aβ aggregation and associated toxicity. Moreover, betalains' ability to regulate NF-κB and Nrf2 pathways underscores their therapeutic promise in combating neurodegeneration induced by oxidative stress and chronic inflammation.
7. Bioavailability
Betanin's oral bioavailability is low and highly variable, and depends substantially on the food matrix from which it is consumed. Betalains are biologically effective but their low bioavailability limits their therapeutic potential. Factors such as food matrix interactions, absorption mechanisms, and biotransformation processes in the gut play a crucial role in modulating betalain absorption and bioavailability.
Betanin is limited by MRP2-mediated efflux, which reduces its intestinal absorption. Indicaxanthin's absorption is more efficient and its bioavailability is higher. The food matrix did not affect indicaxanthin's absorption, but betanin's absorption from beetroot was lower compared to cactus pear.
A human crossover study comparing beetroot juice and whole beetroot demonstrated a striking matrix effect. Despite the relatively high amount of betanin present in both the beetroot juice (BTJ) and whole beetroot food (BF), it could not be identified in plasma at any time point after consumption (1–8 h). These findings conflict with a previous study in which betanin was identified in plasma at relatively high concentrations (~0.2 μmol/l) 2 h after consuming 500 g of fresh cactus pear fruit containing 16 mg of betanin. Epithelial transport was much lower when betanin was derived from red beetroot, suggesting that the rate of absorption was inhibited by beetroot's food matrix.
A human study found that only 0.5–0.9% of betanin was excreted in urine after the consumption of red beet juice, supporting the idea of limited absorption due to the food matrix. Based on the results obtained, it was assumed that either the bioavailability of the betalains is low or that renal clearance is a minor route of systemic elimination for these compounds.
Studies on human subjects have shown that cactus pear is a more bioavailable source of betanin and indicaxanthin. After ingesting 500 g of cactus pear pulp, both compounds peaked in plasma concentration after 3 h.
8. Scientific Evidence by Area of Use
8.1 Antioxidant / Oxidative Stress Reduction
In vitro / preclinical: Betanin demonstrates potent free-radical scavenging in numerous in vitro assays (DPPH, ABTS, FRAP, TEAC) and has been shown to suppress lipid peroxidation markers. Beetroot is an exceptionally rich source of antioxidants, with betalain pigments — especially betacyanins — being amongst the most active compounds capable of reducing oxidative stress. The administration of betalains proved significant protective effects against oxidative stress in several in vitro or in vivo experimental models.
Human evidence: A human intervention study of atherosclerotic cardiovascular disease demonstrated that a red beetroot-derived betalain-rich supplement provides beneficial effects to alleviate atherogenic risk factors, homocysteine, and low-density lipoprotein. Broader human evidence for isolated betanin's antioxidant effects in healthy populations remains limited; most studies use whole-beet preparations and cannot separate betanin from co-occurring nitrate or polyphenols. Evidence strength: Preliminary; promising in vitro and some limited human evidence, but not yet well-characterized in controlled trials for betanin specifically.
8.2 Anti-inflammatory Effects and Osteoarthritis
In vitro / preclinical: Betanin inhibits NF-κB signaling and downstream pro-inflammatory cytokine production. In preclinical studies, betanin suppressed TNF-α, IL-6, GRO-alpha, and RANTES.
Human evidence: Although data concerning the anti-inflammatory effects of betalains in humans are scarce, oral administration of beetroot-derived betalain-rich capsules (providing 35, 70, or 100 mg betalains/day) for 10 days has been demonstrated to be an effective approach to reducing pain and inflammation in patients suffering from osteoarthritis. That study found that 35, 70, and 100 mg of betalain supplementation resulted in a significant reduction in inflammatory cytokines — TNF alpha, IL-6, GRO-alpha, and RANTES — which translated into a dose-dependent reduction in pain scores. This is a notable human dataset, but it examined a betalain-rich mixture rather than pure betanin. Evidence strength: Modest; a small number of human trials with positive results, but populations are small and preparations are mixed-betalain rather than betanin-isolate.
8.3 Cardiovascular Health
Preclinical: Betanin was capable of modulating ROS generation and gene expression to activate antioxidant enzymes and reduce cytokine release, preventing endothelial damage and atherogenesis. However, preclinical studies specifically examining betanin's direct blood-pressure effects have produced conflicting results. Research suggests that betanin alone does not play a central role in the beetroot-induced acute lowering of blood pressure effect; the vasorelaxant effect observed in clinical studies may be due to a synergistic effect of the various active substances in beetroot. One in vivo study demonstrated that acute intravenous betanin administration did not promote blood pressure reduction in rats but promoted a transient increase instead. A study comparing beetroot and sodium nitrate to control hypertension in obese rats found similar functional and molecular responses, suggesting that the nitrate content of beetroot was the factor primarily responsible for cardiovascular improvement rather than betanin.
Human evidence: A clinical trial showed that betalain-/betacyanin-rich supplements (50 mg per day for 14 days) increased the levels of sirtuin-1 and decreased the levels of lipoxygenase-1 and C-reactive protein in patients with cardiovascular disease. In that study, a notable elevation in SIRT1 levels and a considerable decrease in the expression levels of LOX1 and plasma concentration of high-sensitive C-Reactive Protein (hs-CRP) were observed. Additionally, betalain-rich supplements (50 mg of betalain/betacyanins for 2 weeks) lowered systolic and diastolic blood pressure in human volunteers.
A completed randomized, double-blind, placebo-controlled, crossover clinical trial (NCT06117007) conducted at King's College London investigated the effects of beetroot-derived betalains on cardiovascular health, sleep, and quality of life in healthy middle-aged individuals. Published results from this trial were not yet available in the sources retrieved. Evidence strength: Promising but preliminary for betanin specifically; cardiovascular benefits of beetroot juice are more robustly attributed to its nitrate content than to betanin.
8.4 Exercise Performance and Recovery
Several small randomized crossover trials have tested betalain-rich concentrates (BRC) derived from sugar- and nitrate-depleted beetroot, allowing investigators to partially distinguish betalain effects from nitrate effects.
Thirteen competitive male runners (25.3 ± 5.4 years) completed two double-blind, cross-over, randomized trials separated by seven days. Each trial was preceded by six days of supplementation with 100 mg of BRC or control. On the seventh day, exercise trials commenced 150 min after supplementation with 50 mg BRC or control and consisted of 30 min of treadmill running followed by a 5-km time trial. During exercise at the same intensity, BRC resulted in a 3% lower heart rate, a 15% lower rate of perceived exertion (RPE), and a 14% lower blood lactate concentration compared to control. Five-kilometer TT duration was faster in 10 of 13 subjects, and RPE was lower with the BRC treatment.
A similar design was applied to triathletes. Twenty-two triathletes (age 38 ± 11 years) completed 2 double-blind, crossover, randomized trials. Each trial was preceded by 6 days of supplementation with 100 mg·day−1 of BRC or placebo. On the 7th day of supplementation, exercise trials commenced 120 min after ingestion of 50 mg BRC or placebo and consisted of 40 min of cycling followed by a 10-km running time trial.
A 2025 randomized triple-blind placebo-controlled crossover trial found that a single dose of BRC did not enhance running economy (RE) or VO2max. However, observed improvements in exercise heart rate, RPE, and skeletal muscle oxygenation (SmO2) suggest that BRC may confer cardiovascular benefits for exercise and recovery.
Evidence strength: Small but methodologically sound human trials in athletic populations suggest potential benefits on heart rate, perceived exertion, and blood lactate during exercise. Sample sizes are small, and confirmatory trials are needed. Betanin's specific contribution versus other beet compounds remains incompletely characterized even in nitrate-depleted BRC formulations.
8.5 Neuroprotection (Alzheimer's Disease, Parkinson's Disease, Ischemia)
Preclinical (animal and in vitro): Pre-clinical studies have demonstrated the neuroprotective effects of betanin by virtue of its potential to ameliorate oxidative stress, neuroinflammation, abnormal protein aggregation, and cell death. These effects are linked to the direct upregulation of the Nrf2-Keap1-ARE and SIRT1 signaling pathways.
In a mouse model of cerebral ischemia-reperfusion injury, forty male ICR mice were divided into sham-vehicle, IR-vehicle, IR-Bet50, and IR-Bet100 groups. After 2 weeks of oral administration of normal saline or 50 mg/kg or 100 mg/kg of betanin, mice were subjected to IR induction using 30-min bilateral common carotid artery occlusion, followed by 24 h of reperfusion. The use of betanin as preventive therapy provided protection against brain infarction, oxidative stress, damage to vulnerable neurons, and white matter degeneration.
Betanin administration has been found to restore cholinergic functions, increase brain antioxidant capacity, and significantly boost brain-derived neurotrophic factor levels in a scopolamine-induced cognitive impairment zebrafish model.
Human evidence: There has been growing interest in the study of preventive effects of betalains on age-related, degenerative brain diseases. The aim of reviews in this area is to evaluate the potential neuroprotective role of betalains in the prevention of neurodegenerative diseases like Alzheimer's disease and Parkinson's disease, as well as other types of neurodegenerative and ischemic brain injuries. Beetroot-based supplements may improve cognitive performance in the short term. However, most human studies are of limited duration and involve modest sample sizes, making long-term neuroprotective conclusions premature.
Evidence strength: All controlled evidence in Alzheimer's disease, Parkinson's disease, and cerebral ischemia is preclinical (animal and cell models). No adequately powered human clinical trials of betanin for neurodegeneration have been published to date.
8.6 Anticancer Effects
Preclinical: Oral squamous cell carcinoma (OSCC) is a type of human malignancy with a high mortality ratio. Betanin has been reported to exert a preventive role and cytotoxic activity on numerous cancer cell lines. In osteosarcoma MG-63 cells, betanin was shown to inhibit the PI3K/AKT/mTOR/S6 signaling pathway. Studies on oral squamous cancer cells SCC131 and SCC4 demonstrated that betanin can inhibit cell viability and promote apoptosis via NF-κB/PI3K/Akt pathways.
Human evidence: There is no published human clinical trial evidence supporting the use of betanin as an anticancer therapy. All anticancer findings are in vitro (cell lines). Evidence strength: Very preliminary; in vitro only. No clinical translation established.
8.7 Hypolipidemic and Antidiabetic Effects
Studies have demonstrated that betalains can effectively lower blood glucose levels, enhance insulin secretion, and reduce oxidative stress, positioning them as a valuable functional food component for diabetes control. Their ability to inhibit critical enzymes such as α-amylase and α-glucosidase, which are involved in carbohydrate metabolism, has been demonstrated. These findings come primarily from preclinical models.
In human data, body weight, body mass index (BMI), and LDL-cholesterol were decreased in obese human volunteers who consumed freeze-dried red beet leaves (28 g) for 4 weeks. Another study showed that food supplements rich in betalains lowered the total cholesterol, triglyceride, and low-density lipoprotein (LDL) levels in 48 male patients. It was suggested on this basis that betalains may be useful in the management of hyperlipidemia. Further research is necessary to explore their long-term safety, optimal dosing, and mechanisms of action in humans to solidify betalains as viable nutraceutical options in the management of hyperlipidemia and related cardiovascular disorders.
Evidence strength: Preclinical data are encouraging; limited human studies show directional effects on lipids and glucose but sample sizes are small and preparations used are whole beet extracts, not pure betanin.
8.8 Hepatoprotective and Nephroprotective Effects
Preclinical studies have reported that betanin and betalain-rich preparations protect against liver and kidney injury induced by toxic agents (gentamicin nephrotoxicity, carbon tetrachloride hepatotoxicity). The plant's components, including betanin, the major element extracted from red beet, have presented a therapeutic defense in inflammatory events, tumors, and metabolic syndrome. These findings remain preclinical; no controlled human trials have been conducted for hepatoprotective or nephroprotective endpoints.
9. Body Systems and Health Areas Associated with Betanin
- Cardiovascular system: Antioxidant and anti-inflammatory protection of vascular endothelium; reduction of atherogenic risk factors (LDL, homocysteine, hs-CRP) reported in limited human studies; direct blood pressure effects are weak and appear to be nitrate-mediated rather than betanin-mediated.
- Musculoskeletal system: Reduction of exercise-induced oxidative stress and muscle damage; anti-inflammatory effects documented in a small human osteoarthritis trial.
- Nervous system: Preclinical neuroprotective activity against models of Alzheimer's disease, Parkinson's disease, and ischemia-reperfusion injury; no controlled clinical evidence yet established.
- Immune/inflammatory system: Modulation of NF-κB and Nrf2 pathways; reduction of pro-inflammatory cytokines (TNF-α, IL-6) documented in vitro and in some human studies.
- Metabolic/endocrine system: Preclinical evidence for anti-diabetic enzyme inhibition (α-amylase, α-glucosidase) and hypolipidemic activity; limited human data.
- Oncology: In vitro anticancer activity via mitochondrial apoptosis and PI3K/Akt pathway inhibition across multiple cancer cell lines; no clinical translation.
- Hepatic and renal systems: Preclinical cytoprotective evidence; no human clinical data.
10. Dosage Forms and Dosages Reported in Studies
Reported dosing varies substantially by preparation type (whole juice, standardized extract, or concentrate), making direct comparison difficult.
- Beetroot juice (single dose, human bioavailability): Subjects were given 250 ml of beetroot juice (BTJ), an isocaloric placebo, or 300 g cooked beetroot in a randomized crossover design. 500 mL of beetroot juice has been administered as a single dose in healthy volunteers and is estimated to contain approximately 360 mg of betanin.
- Beetroot juice (repeat-dose cardiovascular/exercise trials): A range of 140 to 250 mL beetroot juice over 7 days to 4 weeks has been used in trials with nitrate dosing that ranged from 5.1 to 45 mmol/day.
- Betalain-rich concentrate (BRC) capsules — exercise performance (competitive runners): Six days of supplementation with 100 mg of BRC per day, followed by 50 mg BRC on the exercise day, 150 min before testing. Each 50 mg capsule contained 12.5 mg betalains.
- BRC capsules — triathletes: 6 days of supplementation with 100 mg·day−1 of BRC or placebo, followed by 50 mg BRC or placebo on the exercise day (120 min before testing).
- Betalain-rich capsules — osteoarthritis (human trial): Subjects received beetroot-derived betalain-rich capsules providing 35, 70, or 100 mg betalains per day for 10 days.
- Betalain-rich supplement — coronary artery disease patients: Participants received a betalains-rich supplement of red beetroot, a betacyanins-rich supplement of Opuntia stricta, and a placebo daily for two weeks in a crossover design. The dose was reported as 50 mg of betalain/betacyanins per day.
- Animal studies (ischemia model — mice): 50 mg/kg or 100 mg/kg of betanin administered orally for 2 weeks prior to ischemia induction.
No authoritative regulatory body (EFSA, FDA, WHO) has established a defined therapeutic dosage range or recommended daily intake for betanin as a supplement. The dosages listed above are as reported in individual research studies only.
11. Safety Considerations
11.1 Regulatory Safety Status
EFSA's Panel concluded that the currently available toxicological database was inadequate to establish an acceptable daily intake (ADI) for beetroot red as defined by the specifications set for the food additive E 162. However, the colouring principles in E 162 are natural dietary constituents having a long history of food consumption. In addition, the betanin exposure resulting from the use of beetroot red (E 162) as food additive is in the same range as the exposure to betanin from the regular diet.
EFSA concluded that the currently available database was inadequate to establish an ADI for beetroot red. However, the colouring principles in E 162 are natural dietary constituents having a long history of food consumption, and the exposure to betanin resulting from its use as a food additive is in the same range as the exposure to betanin from the regular diet. Therefore, the Panel concluded that, at the reported use levels, beetroot red (E 162) is not of safety concern.
The majority of approved applications of beetroot extract have no maximum numerical level — only the necessary amount of extract is utilized (quantum satis). However, the application of colors is forbidden in any food products for infants and young children.
E162 is authorised for use in the European Union and is also permitted in the United States as a color additive exempt from certification. In the EU, its status is regulated by Regulation (EC) No. 1333/2008, where it is listed among approved food colorants.
11.2 Toxicological Data Gaps
Acute and short-term toxicity studies are too limited to draw conclusions on these endpoints. There are only limited or inadequate studies available on the chronic toxicity and carcinogenicity of beetroot red, and therefore the Panel could not conclude on these endpoints. No adequate studies on reproduction and developmental toxicity were available.
Studies of acute and short-term toxicity are too limited to draw reliable conclusions. The genotoxic potential of betanin could not be assessed due to lack of data. Long-term studies of chronic toxicity, carcinogenicity, and effects on reproductive function are practically absent.
In animal toxicology work, there were no signs of acute or subacute toxicity and no abnormalities in organ function, biochemical markers, or histological structure over 35 days in animal studies. Betalains extracted from red pitaya peel showed no toxicity after oral administration of up to 48,500 mg/kg body weight in mice.
11.3 Beeturia (Betacyaniuria)
The most widely documented and clinically significant safety-adjacent effect of betanin consumption is beeturia. Beeturia is a benign medical condition characterized by the pink to deep red discoloration of urine following the consumption of beets or foods containing beetroot pigments, such as betacyanins (primarily betanin). This phenomenon occurs due to the direct absorption and unmetabolized excretion of these water-soluble pigments through the gastrointestinal tract into the urine, without significant hepatic or renal processing. It is typically harmless and self-resolving within 24 to 48 hours after ingestion ceases.
The typical color can range from pink to deep red, and this phenomenon is prevalent in 10% to 14% of the population, with increased frequency noted for those who are iron deficient or afflicted with malabsorptive diseases. Specifically, Watson et al. found beeturia in 14% of the general population, but in 80% of iron-deficient subjects. They suggested that iron and betacyanin may compete for an intestinal mucosal acceptor substance, perhaps apoferritin.
Beet consumption can also cause harmless red or pink discoloration of the stool (mimicking hematochezia or rectal bleeding) in many individuals due to the betanin pigment; this discoloration is benign and resolves within 48 hours after stopping beet consumption.
The microscopic findings of a urinalysis will be negative for red blood cells but will have continued discoloration on gross inspection, distinguishing beeturia from true hematuria. The main pitfall of beeturia is the risk of misdiagnosing this chief complaint as a urinary tract infection or referring for cystoscopy or further evaluation.
11.4 Allergic Reactions
Betanin did not stimulate and even inhibited IgE and IgG in one study, demonstrating the lack of allergic response to the pigment. Adverse reactions to E162 are extremely rare. Unlike some synthetic azo dyes, beetroot red has not been linked to hyperactivity, allergic sensitisation, or intolerance reactions in the general population. The EFSA Panel confirmed that there was no higher risk of sensitivity or intolerance to beetroot red extract in the specific population of children with cow's milk allergy or other protein allergies.
11.5 Stability and Processing Contaminants
During extraction and drying, if technological control is insufficient, additive E162 may be contaminated with pesticide residues, disinfectants, or by-products. Such impurities may affect the toxicological profile of the colorant, confirming the need for strict standards and quality control in the production of the additive.
11.6 Interactions
No pharmacokinetic drug-drug interaction data for isolated betanin have been published in peer-reviewed literature. The interaction between beetroot consumption and iron absorption is the most documented biochemical interaction. The increased prevalence of beeturia in iron-deficient individuals and the hypothesis that iron and betacyanin compete for an intestinal mucosal acceptor substance suggest a pharmacokinetic interplay at the level of GI absorption. The cardiovascular benefits widely attributed to beetroot juice (particularly blood pressure effects) are mediated via its nitrate content and the nitrate-nitrite-NO pathway, rather than betanin itself, based on comparative animal studies. Athletes and individuals taking medications affecting nitric oxide metabolism should account for this distinction when interpreting the broader beetroot literature.
References
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