Red Bush Tea
Scientific Name(s): Aspalathus linearis (Burm. f.) R. Dahlgr.
Common Name(s): Red bush tea, Rooibos tea, Rooibosch
Medically reviewed by Drugs.com. Last updated on Sep 16, 2019.
Limited clinical studies exist to recommend red bush tea for any indication. Due to the plant’s potential for improving oxidative stress, it may have a role in diabetes and cardiovascular disease.
The traditional dosage of the tea is 1 to 4 teaspoons of dry leaf tea per cup taken up to 3 times per day. Limited studies have used 6 cups of rooibos tea daily for 6 weeks.
Contraindications have not been identified.
Information regarding safety and efficacy in pregnancy and lactation is lacking.
In a study using human serum, rooibos acted as an angiotensin-converting enzyme (ACE) inhibitor in a manner similar to that of enalaprilat.
Information regarding adverse effects is lacking. A study of human volunteers receiving 6 cups of tea daily for 6 weeks noted increased serum levels of creatinine, as well as ALT and AST enzymes.
Long-term, high-dose use may impair kidney and liver function, but few case reports exist.
Rooibos ("red bush") grows as a low shrub, reaching a height of 1.2 to 1.5 m. It has long, needle-like leaves and small yellow flowers. The plant is native to South Africa and is cultivated extensively for its commercial value as a substitute for common tea. The leaves and twigs are collected, washed, bruised, fermented, dried, cut, and packaged for use as teas. During this process, the leaves change from green to brick red due to the release of a red pigment found in the leaves and stems.1 Synonyms are Borbonia pinifolia Marloth or Aspalathus contaminata (Thunb.) Druce.
"Bush teas" are common throughout Africa and are frequently used as substitutes for common tea. Red bush tea has been popular in South Africa for decades, and commercial preparations are sometimes found in Europe and the United States. In 1994, an American company registered the name "Rooibos" with the United States Patent and Trademark Office. However, the American Herbal Products Association and a number of import companies successfully petitioned to defeat the trademark in 2005, returning the name to the public domain.2 In 2013, the South African Department of Trade and Industry issued geographic indicator trade restrictions on the name rooibos in that country.3
The tea’s lack of caffeine and tannin make it popular as a fragrant and bittersweet, nonstimulating beverage. It has also been used to treat asthma, colic, eczema, headache, nausea, and mild depression.1, 3, 4, 5
Chemical constituents detailed for red bush tea primarily consist of flavonoids (ie, catechin, quercetin, rutin, vitexin, dihydrochalcones aspalathin, nothofagin) and phenolic acids (ie, caffeic, p-coumaric, ferulic, vanillic acids).5, 6, 7, 8, 9 Aspalathin, a dihydrochalcone C-glucoside, was identified in 1965,10 with green (unfermented) rooibos possibly containing more aspalathin than the commercial fermented rooibos tea.11 An enolic phenylpyruvic acid glucoside has also been identified.12
Phenolic content of extracts varies by season and production methods.13
Red bush tea contains no caffeine or pyrrolizidine alkaloids and low amounts of tannins (less than 5%), as determined by spectrophotometry and gas chromatography.14 The tea contains a relatively high level of vitamin C, as well as some sodium, potassium, magnesium, calcium, and zinc.5, 6
Uses and Pharmacology
Antioxidant activity has been demonstrated in laboratory experiments and in cellular systems, and in vivo studies have been conducted in rodents and quails.9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 Reported total antioxidant activity varies depending on the assay method and on fermentation and processing methods.27
A small, single-dose study among healthy human volunteers did not detect any change in total antioxidant capacity using the oxygen radical absorbance capacity assay,28 while another study found small increases.29 Following consumption of 6 cups of rooibos tea daily for 6 weeks, improved antioxidant status and lipid profiles (decreased low-density lipoprotein [LDL] and triacylglycerol, increased high-density lipoprotein [HDL]) were reported among adults with risk markers for cardiovascular disease.30
Suppression of mutagenic activity has been demonstrated in rodents, including studies of liver and skin tumorigenesis,27, 31, 32, 33, 34 with rooibos tea lowering activity to a greater extent than green tea in at least 1 study.31
No clinical data exist regarding the use of rooibos in cancer.
In hyperlipidemic mice, aqueous rooibos extract reduced serum cholesterol, triglyceride, and free fatty acid concentrations, and decreased adipocyte size and number.35 An in vitro study demonstrated inhibition of adipogenesis following treatment with hot water–soluble solids from fermented rooibos.36 Anticoagulant activity has been described for aspalathin and nothofagin in human umbilical endothelial cells and in mice.37 These 2 chemical constituents have also shown activity in inhibiting various mechanisms involved in vascular inflammation.6, 38, 39 In mice, hypotensive effects were demonstrated, possibly via potassium channel modulation.40
Following daily consumption of 6 cups of rooibos tea for 6 weeks, improved antioxidant status and lipid profiles (decreased LDL and triacylglycerol, increased HDL) were reported among adults with risk markers for cardiovascular disease.30 In a study using human serum, rooibos acted as an ACE inhibitor in a manner similar to that of enalaprilat.41
Experiments in rodents suggest that extracts of rooibos may have antidiabetic effects, with suppressed increases in fasting blood glucose levels demonstrated. Increased glucose uptake and insulin secretion, as well as reduced insulin resistance, are possible mechanisms of action. Green rooibos,11, 42 aspalathin alone,43 and in combination with rutin,44 and an enolic phenylpyruvic acid glucoside have all been studied.12, 44
There are no clinical data regarding the use of rooibos in diabetes.
Anti-inflammatory effects of rooibos and of the constituents aspalathin and nothofagin have been studied in models of colitis and vascular inflammation. Suppression of tumor necrosis factor-alpha and interleukin has been demonstrated.16, 39, 45
There are no clinical data regarding the use of rooibos as an anti-inflammatory agent.
The effect of rooibos, aspalathin, and nothofagin on steroid hormone biosynthesis has been investigated.46, 47 Rooibos consumption increased cortisone plasma levels in males and reduced cortisol to cortisone ratios in both males and females.48
Aspalathin was shown to inhibit xanthine oxidase activity and reduce plasma uric acid levels in mice.49
Bronchodilator and antispasmodic effects were demonstrated in mice, possibly via potassium channel modulation.40
Rooibos extracts may possess antibacterial activity, as demonstrated in limited experiments.25, 50
The traditional dosage of the tea is 1 to 4 teaspoons of dry leaf tea per cup taken up to 3 times per day.5
Limited studies have used doses of 6 cups of rooibos tea per day for 6 weeks.30, 48 Urinary excretion of rooibos metabolites when taken as a tea has been investigated.51
Pregnancy / Lactation
Information regarding safety and efficacy in pregnancy and lactation is lacking. Phytoestrogenic effects have been suggested.52, 53, 54 Rooibos tea has been shown to interfere with steroidogenesis in vivo,53 possibly due to antioxidant properties, and to improve sperm motility in rats.17, 55
No effect on iron absorption has been reported.27 In a study using human serum, rooibos acted as an ACE inhibitor in a manner similar to that of enalaprilat.41 Anticoagulant activity has been described for aspalathin and nothofagin in human umbilical endothelial cells and in mice.37 A study on the interaction of rooibos with cimetidine was inconclusive in its findings.56
Information regarding adverse effects is lacking.27 Although microbial contaminants (including Salmonella) may be present due to the fermentation process used to derive the tea product, few reports of contamination exist.4, 57
Animal studies have shown increased creatinine levels, but no changes in kidney tissue on histology.55 A study of human volunteers receiving 6 cups of tea daily for 6 weeks noted increased serum levels of creatinine, as well as ALT and AST enzymes.30 A case of hepatotoxicity has been reported in a 37-year-old man who consumed 10 cups/day of red bush tea for more than a year. He was scheduled for an emergency appendectomy where his preoperative work-up revealed elevated liver enzymes and thrombocytopenia. All other causes for the hepatotoxicity were ruled out and the tea was deemed to be the responsible agent.60
Long-term, high-dose use may impair liver and kidney function, but few case reports exist.14, 30, 55, 58 Interference with the acrosome reaction, required for penetration into an egg, has been suggested.55
- Aspalathus contaminata (Thunb.) Druce
- Borbonia pinifolia Marloth
1. Watt J, Breyer-Brandwijk MG. Medicinal and Poisonous Plants of Southern and Eastern Africa
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2. American Herbal Products Association. Rooibos Trademark Abandoned. American Herbal Products Association website. http://ahpa.org/Default.aspx?tabid=145&aId=216
. Updated 2015. Accessed April 14, 2015.
3. Merchandise Marks Act, 1941 (Act 17 of 1941), Final Prohibition on the Use of Certain Words. Department of Trade and Industry, Republic of South Africa. September 6, 2013. http://www.gov.za/sites/www.gov.za/files/36807_gen911.pdf. Accessed August 6, 2015.
4. Joubert E, de Beer D, Malherbe CJ, et al. Occurrence and sensory perception of Z-2-(beta-d-glucopyranosyloxy)-3-phenylpropenoic acid in rooibos (Aspalathus linearis
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6. Duke J, Bogenschutz-Godwin M, duCellier J, Duke P. Handbook of Medicinal Herbs
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7. Ku SK, Kwak S, Kim Y, Bae JS. Aspalathin and Nothofagin from Rooibos (Aspalathus linearis
) inhibits high glucose-induced inflammation in vitro and in vivo. Inflammation
8. Krafczyk N, Glomb MA. Characterization of phenolic compounds in rooibos tea. J Agric Food Chem
9. de Beer D, Malherbe CJ, Beelders T, Willenburg EL, Brand DJ, Joubert E. Isolation of aspalathin and nothofagin from rooibos (Aspalathus linearis
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10. Joubert E, Winterton P, Britz TJ, Gelderblom WC. Antioxidant and pro-oxidant activities of aqueous extracts and crude polyphenolic fractions of rooibos (Aspalathus linearis
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11. Han Z, Achilonu MC, Kendrekar PS, et al. Concise and scalable synthesis of aspalathin, a powerful plasma sugar-lowering natural product. J Nat Prod
12. Kamakura R, Son MJ, de Beer D, Joubert E, Miura Y, Yagasaki K. Antidiabetic effect of green rooibos (Aspalathus linearis
) extract in cultured cells and type 2 diabetic model KK-A mice. Cytotechnology
13. Muller CJ, Joubert E, Pheiffer C, et al. Z-2-(beta-D-glucopyranosyloxy)-3-phenylpropenoic acid, an alpha-hydroxy acid from rooibos (Aspalathus linearis
) with hypoglycemic activity. Mol Nutr Food Res
14. Joubert E, Beelders T, de Beer D, Malherbe CJ, de Villiers AJ, Sigge GO. Variation in phenolic content and antioxidant activity of fermented rooibos herbal tea infusions: role of production season and quality grade. J Agric Food Chem
15. McGaw LJ, Steenkamp V, Eloff JN. Evaluation of Athrixia bush tea for cytotoxicity, antioxidant activity, caffeine content and presence of pyrrolizidine alkaloids. J Ethnopharmacol
16. Ajuwon OR, Katengua-Thamahane E, Van Rooyen J, Oguntibeju OO, Marnewick JL. Protective effects of rooibos (Aspalathus linearis
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) supplementation on tert-butyl hydroperoxide-induced oxidative hepatotoxicity in Wistar rats [published online 2013]. Evid Based Complement Alternat Med
17. Ajuwon OR, Oguntibeju OO, Marnewick JL. Amelioration of lipopolysaccharide-induced liver injury by aqueous rooibos (Aspalathus linearis
) extract via inhibition of pro-inflammatory cytokines and oxidative stress [published online October 13, 2014]. BMC Complement Altern Med
18. Awoniyi DO, Aboua YG, Marnewick J, Brooks N. The effects of rooibos (Aspalathus linearis
), green tea (Camellia sinensis
) and commercial rooibos and green tea supplements on epididymal sperm in oxidative stress-induced rats. Phytother Res
19. Ayeleso A, Brooks N, Oguntibeju O. Modulation of antioxidant status in streptozotocin-induced diabetic male Wistar rats following intake of red palm oil and/or rooibos. Asian Pac J Trop Med
20. Canda BD, Oguntibeju OO, Marnewick JL. Effects of consumption of rooibos (Aspalathus linearis
) and a rooibos-derived commercial supplement on hepatic tissue injury by tert-butyl hydroperoxide in Wistar rats [published online March 11, 2014]. Oxid Med Cell Longev
21. Chen W, Sudji IR, Wang E, Joubert E, van Wyk BE, Wink M. Ameliorative effect of aspalathin from rooibos (Aspalathus linearis
) on acute oxidative stress in Caenorhabditis elegans
22. Dludla PV, Muller CJ, Louw J, et al. The cardioprotective effect of an aqueous extract of fermented rooibos (Aspalathus linearis
) on cultured cardiomyocytes derived from diabetic rats. Phytomedicine
23. Fukasawa R, Kanda A, Hara S. Anti-oxidative effects of rooibos tea extract on autoxidation and thermal oxidation of lipids. J Oleo Sci
24. Hong IS, Lee HY, Kim HP. Anti-oxidative effects of Rooibos tea (Aspalathus linearis
) on immobilization-induced oxidative stress in rat brain [published online January 21, 2014]. PLoS One
25. Pantsi WG, Marnewick JL, Esterhuyse AJ, Rautenbach F, van Rooyen J. Rooibos (Aspalathus linearis
) offers cardiac protection against ischaemia/reperfusion in the isolated perfused rat heart. Phytomedicine
26. Simpson MJ, Hjelmqvist D, Lopez-Alarcon C, et al. Anti-peroxyl radical quality and antibacterial properties of rooibos infusions and their pure glycosylated polyphenolic constituents. Molecules
27. Ulicná O, Vancová O, Waczulíkova I, et al. Does rooibos tea (Aspalathus linearis
) support regeneration of rat liver after intoxication by carbon tetrachloride? Gen Physiol Biophys
28. McKay DL, Blumberg JB. A review of the bioactivity of South African herbal teas: rooibos (Aspalathus linearis
) and honeybush (Cyclopia intermedia
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29. Breiter T, Laue C, Kressel G, Groll S, Engelhardt UH, Hahn A. Bioavailability and antioxidant potential of rooibos flavonoids in humans following the consumption of different rooibos formulations. Food Chem
30. Villaño D, Pecorari M, Testa MF, et al. Unfermented and fermented rooibos teas (Aspalathus linearis
) increase plasma total antioxidant capacity in healthy humans. Food Chem
31. Marnewick JL, Rautenbach F, Venter I, et al. Effects of rooibos (Aspalathus linearis
) on oxidative stress and biochemical parameters in adults at risk for cardiovascular disease. J Ethnopharmacol
32. Marnewick JL, van der Westhuizen FH, Joubert E, Swanevelder S, Swart P, Gelderblom WC. Chemoprotective properties of rooibos (Aspalathus linearis
), honeybush (Cyclopia intermedia
) herbal and green and black (Camellia sinensis
) teas against cancer promotion induced by fumonisin B1 in rat liver. Food Chem Toxicol
33. Marnewick J, Joubert E, Joseph S, Swanevelder S, Swart P, Gelderblom W. Inhibition of tumour promotion in mouse skin by extracts of rooibos (Aspalathus linearis
) and honeybush (Cyclopia intermedia
), unique South African herbal teas. Cancer Lett
34. van der Merwe JD, Joubert E, Richards ES, et al. A comparative study on the antimutagenic properties of aqueous extracts of Aspalathus linearis
(rooibos), different Cyclopia
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35. Snijman PW, Swanevelder S, Joubert E, Green IR, Gelderblom WC. The antimutagenic activity of the major flavonoids of rooibos (Aspalathus linearis
): some dose-response effects on mutagen activation-flavonoid interactions. Mutat Res
36. Beltran-Debon R, Rull A, Rodriguez-Sanabria F, et al. Continuous administration of polyphenols from aqueous rooibos (Aspalathus linearis
) extract ameliorates dietary-induced metabolic disturbances in hyperlipidemic mice. Phytomedicine
37. Sanderson M, Mazibuko SE, Joubert E, et al. Effects of fermented rooibos (Aspalathus linearis
) on adipocyte differentiation. Phytomedicine
38. Ku SK, Lee W, Kang M, Bae JS. Antithrombotic activities of aspalathin and nothofagin via inhibiting platelet aggregation and FIIa/FXa. Arch Pharm Res
39. Kwak S, Han MS, Bae JS. Aspalathin and nothofagin from rooibos (Aspalathus linearis
) inhibit endothelial protein C receptor shedding in vitro and in vivo. Fitoterapia
40. Lee W, Bae JS. Anti-inflammatory effects of Aspalathin and Nothofagin from rooibos (Aspalathus linearis
) in vitro and in vivo. Inflammation
41. Khan AU, Gilani AH. Selective bronchodilatory effect of Rooibos tea (Aspalathus linearis
) and its flavonoid, chrysoeriol. Eur J Nutr
42. Persson IA. The pharmacological mechanism of angiotensin-converting enzyme inhibition by green tea, Rooibos and enalaprilat - a study on enzyme kinetics. Phytother Res
43. Mazibuko SE, Muller CJ, Joubert E, et al. Amelioration of palmitate-induced insulin resistance in C2C12 muscle cells by rooibos (Aspalathus linearis
44. Kawano A, Nakamura H, Hata S, Minakawa M, Miura Y, Yagasaki K. Hypoglycemic effect of aspalathin, a rooibos tea component from Aspalathus linearis
, in type 2 diabetic model db/db mice. Phytomedicine
45. Muller CJ, Joubert E, de Beer D, et al. Acute assessment of an aspalathin-enriched green rooibos (Aspalathus linearis
) extract with hypoglycemic potential. Phytomedicine
46. Baba H, Ohtsuka Y, Haruna H, et al. Studies of anti-inflammatory effects of Rooibos tea in rats. Pediatr Int
47. Schloms L, Storbeck KH, Swart P, Gelderblom WC, Swart AC. The influence of Aspalathus linearis
(Rooibos) and dihydrochalcones on adrenal steroidogenesis: quantification of steroid intermediates and end products in H295R cells. J Steroid Biochem Mol Biol
48. Schloms L, Swart AC. Rooibos flavonoids inhibit the activity of key adrenal steroidogenic enzymes, modulating steroid hormone levels in H295R cells. Molecules
49. Schloms L, Smith C, Storbeck KH, Marnewick JL, Swart P, Swart AC. Rooibos influences glucocorticoid levels and steroid ratios in vivo and in vitro: a natural approach in the management of stress and metabolic disorders? Mol Nutr Food Res
50. Kondo M, Hirano Y, Nishio M, Furuya Y, Nakamura H, Watanabe T. Xanthine oxidase inhibitory activity and hypouricemic effect of aspalathin from unfermented rooibos. J Food Sci
51. Park HJ, Park KC, Yoon KS. Effect of rooibos (Aspalathus linearis
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53. Juráni M, Lamosová D, Mácajová M, Kostál L, Joubert E, Greksák M. Effect of rooibos tea (Aspalathus linearis
) on Japanese quail growth, egg production and plasma metabolites. Br Poult Sci
54. Opuwari CS, Monsees TK. Reduced testosterone production in TM3 Leydig cells treated with Aspalathus linearis
(Rooibos) or Camellia sinensis
55. Shimamura N, Miyase T, Umehara K, Warashina T, Fujii S. Phytoestrogens from Aspalathus linearis
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56. Opuwari CS, Monsees TK. In vivo effects of Aspalathus linearis
(rooibos) on male rat reproductive functions. Andrologia
57. Tarirai C, Viljoen AM, Hamman JH. Effects of dietary fruits, vegetables and a herbal tea on the in vitro transport of cimetidine: comparing the Caco-2 model with porcine jejunum tissue. Pharm Biol
58. Swanepoel ML. Salmonella isolated from rooibos tea. S Afr Med J
59. Sinisalo M, Enkovaara AL, Kivisto KT. Possible hepatotoxic effect of rooibos tea: a case report. Eur J Clin Pharmacol
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