Common Names

  • Yerba mate
  • St. Bartholomew’s tea
  • Jesuit’s tea
  • Ilex
  • Hervea
  • Guyaki Paraguay tea
  • Chimarrão
  • Cimmaron

For Patients & Caregivers

Regular use of mate is linked to increased risk of developing prostate, lung, bladder, esophageal, and head and neck cancers.

Mate contains compounds that are thought to have stimulant effects. Mate products have been used both for weight loss and cancer prevention. Some lab studies suggest that mate can stop cancer cell growth, but it has not been shown to prevent or treat cancer in humans. Drinking high doses of mate tea can increase the risk for several types of cancers. Evidence also suggests that drinking very hot mate contributes to its carcicogenic effects.

  • To lose weight
    A small study showed that a product containing mate helped overweight subjects to lose weight. Another small study showed this formula may curb the appetite. However, it is unclear if mate alone has these same effects. In addition, such results and the safety of long-term use would need to be confirmed in larger studies.
  • As a stimulant
    Because of its caffeine content, mate is a known stimulant.
  • To treat depression
    No scientific evidence supports this use.
  • To treat headaches
    Caffeine may increase the effect of some drugs for headache.
  • To relieve fatigue
    Because of its caffeine content, mate is a known stimulant. However, the increased risk of certain cancers likely outweighs any benefits.
  • To improve bone health
    Although a small trial suggest that mate may protect against bone loss, such a benefit may be canceled out by the increased risk for various cancers with chronic mate use. In addition, this was a small group of postmenopausal women in a special program from a specific region, so these findings would not necessarily relate to the general public.
  • To promote urination
    Mate contains caffeine, which can increase urination.
  • To treat cancer
    Some compounds in mate appear to stop certain cancer cells from growing in the lab. However, this has not been studied in humans, and there are also other compounds in mate that can cause cancer.
  • High doses and prolonged use of mate tea are linked to increased risk of prostate, bladder, oral, esophageal, lung, and head and neck cancers.
  • Heavy alcohol use and/or smoking combined with long-term mate use additionally increases the risk of cancer.
  • Due to the caffeine content in mate, the following lab tests may be altered: Blood pressure, catecholamine levels, and bleeding time as measured by PT, PTT, or INR.
  • You are taking chemotherapy drugs: Mate may interfere with the actions of some drugs.
  • You are taking heart or blood pressure medications: Mate may increase the effects of these drugs or cause unwanted side-effects.
  • You are taking stimulant drugs (eg, Ritalin): Mate may increase the side-effects of these drugs.
  • You are taking drugs for depression: Mate may increase the side-effects of these drugs.

Sleep disruption, palpitations, increased heart rate, stomach upset, restlessness, anxiety

Case reports

  • Liver failure was reported in a heavy mate drinker.
  • Withdrawal syndrome occurred in a newborn caused by a mother’s heavy intake of mate.
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For Healthcare Professionals

Ilex paraguariensis

Mate is a plant native to South America. It is widely consumed as a hot beverage known as chimarrão, and is also used in traditional medicine. Mate is valued for its stimulatory effects and promoted as a dietary supplement for weight loss, cardiovascular diseases, and cancer prevention.

Mate demonstrated antioxidant activity (1) and cardioprotective effects (2) in vitro. Obese and hyperlipidemic animal models also suggest antiadipogenic and antilipidemic effects (3) (4). A product containing mate was found to delay gastric emptying (5), and preliminary studies in generally healthy women suggest consumption may have short-term effects on caloric intake and appetite regulation (6). Long-term consumption of mate tea was also weakly associated with better bone health in postmenopausal women (7), but clinical studies are needed to confirm such effects.

In various cancer models, constituents of mate exhibited proteasome (8) and topoisomerase (9) inhibitory properties, as well as anti-inflammatory and apoptotic effects (10) (11). However, no large-scale clinical studies have evaluated the safety and efficacy of mate in humans. Further, epidemiologic data indicate that chronic mate drinkers are at an increased risk of prostate (12), bladder (13) (14) (15), esophageal (16) (17), lung (18), and head and neck cancers (19). This risk appears to be additive when combined with chronic alcohol or tobacco use (20). Evidence also suggests that drinking very hot mate contributes to its carcicogenic effects (33)

  • Appetite suppression
  • Bone health
  • Central nervous system stimulation
  • Depression
  • Fatigue
  • Headaches
  • Promote urination
  • Weight loss

In vitro studies indicate that antioxidant and antimicrobial activity of mate may be due to its polyphenolic content (1) (22) (26), while cardioprotective effects occur through the regulation of nitric oxide (2).  Caffeine, theophylline, and theobromine are the xanthines in mate largely responsible for its stimulatory effects (21) (22) (23) (24) (25).

In animal models, mate regulates adipogenesis through the Wnt pathway (3), reduces lipid peroxidation, improves endothelial function and LPL and HL activities, and modulates lipogenic gene expression (4). Thermogenic properties have been related to enhanced expression of uncoupling proteins, while increased fatty acid oxidation is linked to AMPK phosphorylation in visceral adipose tissue (27).

Anticancer activities of mate extract can occur through proteasome (8) and topoisomerase (9) inhibition. It also reduced DNA damage from oxidative stress (1). In human colon cancer cells, saponins and phenolics in mate demonstrate antiinflammatory activity and induce apoptosis through caspase activation (10) (11). However, other carcinogenic constituents in mate and high temperatures used for brewing could facilitate their solubility and absorption (19) (25) and thus explain associated increased cancer risks.

High doses and prolonged consumption of mate tea are associated with an increased risk of various cancers (12) (13) (14) (15) (16) (17) (18) (19). Concomitant long-term alcohol or tobacco use further increases this risk (20).

  • Patients with hypertension, cardiac disorders, and anxiety should not consume mate (28) (29) (30).
  • Women who are pregnant or breastfeeding should not consume mate (31).

Sleep disruption, arrhythmias, increased heart rate, stomach upset, and anxiety in vulnerable subjects (28) (29) (30).

Case Reports
Hepatic veno-occlusive disease/liver failure:
In an adult woman, linked to the chronic long-term use of mate that contained small amounts of pyrrolizidine alkaloids (32).

Neonatal withdrawal syndrome: Jitteriness, irritability, high-pitched cry, limb hypertonia, and brisk tendon reflexes consistent with neonatal withdrawal syndrome reported in a premature newborn whose mother drank mate during pregnancy. Caffeine and theobromine were detected in high concentrations across various maternal and neonatal samples including breast milk and neonatal urine and hair. Symptoms progressively disappeared by 84 hours of age. However, intermittent irritability was still present at 24 days when the newborn was discharged. Considerable, progressive, and constant reduction of mate consumption to a maximum of 2 cups per day for the duration of breastfeeding was advised (31).

Chemotherapy: Due to its antioxidant activity, mate may interfere with some chemotherapy drugs (1).
Stimulant, cardiac, hypertension, or antidepressant drugs: Due to its caffeine content, mate may interact with these drugs, although specific interactions have not been studied.

Due to the caffeine content in mate, the following lab tests may be altered:

  • Blood pressure
  • Catecholamine levels
  • Bleeding time as measured by PT, aPTT, or INR
  1. Miranda DD, Arcari DP, Pedrazzoli J, Jr., et al. Protective effects of mate tea (Ilex paraguariensis) on H2O2-induced DNA damage and DNA repair in mice. Mutagenesis. Jul 2008;23(4):261-265.

  2. Schinella G, Fantinelli JC, Mosca SM. Cardioprotective effects of Ilex paraguariensis extract: evidence for a nitric oxide-dependent mechanism. Clin Nutr. Jun 2005;24(3):360-366.

  3. Arcari DP, Santos JC, Gambero A, et al. The in vitro and in vivo effects of yerba mate (Ilex paraguariensis) extract on adipogenesis. Food Chem. Nov 15 2013;141(2):809-815.

  4. Gao H, Long Y, Jiang X, et al. Beneficial effects of Yerba Mate tea (Ilex paraguariensis) on hyperlipidemia in high-fat-fed hamsters. Exp Gerontol. Jun 2013;48(6):572-578.

  5. Harrold JA, Hughes GM, O’Shiel K, et al. Acute effects of a herb extract formulation and inulin fibre on appetite, energy intake and food choice. Appetite. Mar 2013;62:84-90.

  6. Gonzalez de Mejia E, Song YS, Ramirez-Mares MV, et al. Effect of yerba mate (Ilex paraguariensis) tea on topoisomerase inhibition and oral carcinoma cell proliferation. J Agric Food Chem. Mar 23 2005;53(6):1966-1973.

  7. Deneo-Pellegrini H, Ronco AL, De Stefani E, et al. Food groups and risk of prostate cancer: a case-control study in Uruguay. Cancer Causes Control. Jul 2012;23(7):1031-1038.

  8. De Stefani E, Correa P, Fierro L, et al. Black tobacco, mate, and bladder cancer. A case-control study from Uruguay. Cancer. Jan 15 1991;67(2):536-540.

  9. De Stefani E, Boffetta P, Deneo-Pellegrini H, et al. Non-alcoholic beverages and risk of bladder cancer in Uruguay. BMC Cancer. 2007;7:57.

  10. Bates MN, Hopenhayn C, Rey OA, et al. Bladder cancer and mate consumption in Argentina: a case-control study. Cancer Lett. Feb 8 2007;246(1-2):268-273.

  11. Szymanska K, Matos E, Hung RJ, et al. Drinking of mate and the risk of cancers of the upper aerodigestive tract in Latin America: a case-control study. Cancer Causes Control. Nov 2010;21(11):1799-1806.

  12. Pintos J, Franco EL, Oliveira BV, et al. Mate, coffee, and tea consumption and risk of cancers of the upper aerodigestive tract in southern Brazil. Epidemiology. Nov 1994;5(6):583-590.

  13. De Stefani E, Fierro L, Correa P, et al. Mate drinking and risk of lung cancer in males: a case-control study from Uruguay. Cancer Epidemiol Biomarkers Prev. Jul 1996;5(7):515-519.

  14. Goldenberg D, Lee J, Koch WM, et al. Habitual risk factors for head and neck cancer. Otolaryngol Head Neck Surg. Dec 2004;131(6):986-993.

  15. Loria D, Barrios E, Zanetti R. Cancer and yerba mate consumption: a review of possible associations. Rev Panam Salud Publica. Jun 2009;25(6):530-539.

  16. Bojic M, Simon Haas V, Saric D, et al. Determination of Flavonoids, Phenolic Acids, and Xanthines in Mate Tea (Ilex paraguariensis St.-Hil.). J Anal Methods Chem. 2013;2013:658596.

  17. Prado Martin JG, Porto E, de Alencar SM, et al. Antimicrobial activity of yerba mate (Ilex paraguariensis St. Hil.) against food pathogens. Rev Argent Microbiol. Apr-Jun 2013;45(2):93-98.

  18. Coelho GC, Gnoatto SB, Bassani VL, et al. Quantification of saponins in extractive solution of mate leaves (Ilex paraguariensis A. St. Hil.). J Med Food. Apr 2010;13(2):439-443.

  19. Kamangar F, Schantz MM, Abnet CC, et al. High levels of carcinogenic polycyclic aromatic hydrocarbons in mate drinks. Cancer Epidemiol Biomarkers Prev. May 2008;17(5):1262-1268.

  20. Bonnet M, Tancer M, Uhde T, et al. Effects of caffeine on heart rate and QT variability during sleep. Depress Anxiety. 2005;22(3):150-155.

  21. Childs E, Hohoff C, Deckert J, et al. Association between ADORA2A and DRD2 polymorphisms and caffeine-induced anxiety. Neuropsychopharmacology. Nov 2008;33(12):2791-2800.

  22. Cohen PA, Ernst E. Safety of herbal supplements: a guide for cardiologists. Cardiovasc Ther. Aug 2010;28(4):246-253.

  23. Martin I, Lopez-Vilchez MA, Mur A, et al. Neonatal withdrawal syndrome after chronic maternal drinking of mate. Ther Drug Monit. Feb 2007;29(1):127-129.

  24. McGee J, Patrick RS, Wood CB, et al. A case of veno-occlusive disease of the liver in Britain associated with herbal tea consumption. J Clin Pathol. Sep 1976;29(9):788-794.

  25. Loomis D, Guyton KZ, Grosse Y, et al. Carcinogenicity of drinking coffee, mate, and very hot beverages. The Lancet Oncology. Jun 15, 2016.

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