History & Overview Annual Report President's Pages Center News Community Affairs
Make a Gift Yankees Universe Fund Fred's Team Thomas Blake Sr. Memorial Research Fund Donating Blood & Platelets Volunteering Thrift Shop Park Avenue Potluck Cookbook
Press Releases Information for Journalists News@MSKCC
Manhattan New Jersey Long Island Westchester
Working at Memorial Sloan-Kettering Work Sites College Recruitment About Nursing Job Fairs & Career Days Job Search & Apply Online
Making an Appointment
Search About Herbs:

Mate

How It Works

Bottom Line: Mate causes lung, bladder, mouth, and esophageal cancer in people who consume it regularly. It is a dangerous herb and should be avoided.

Mate is known to contain caffeine and two similar compounds called theophylline and theobromine. All three compounds elevate the level of cAMP (an important cell signaling molecule) in cells, thus prolonging certain cell activities. This effect at the cellular level is thought to generate its overall stimulant effects. Although no studies in humans have specifically tested the effects of mate, scientists are very familiar with the stimulant effects of these three compounds.

Purported Uses

  • To suppress the appetite
    No scientific evidence supports this use.
  • As a stimulant
    Because of its caffeine content, mate is a known stimulant. However, the increased risk of certain cancers likely outweighs any benefits.
  • To treat depression
    No scientific evidence supports this use.
  • 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 treat headaches
    No scientific evidence supports this use.
  • To treat pain
    No scientific evidence supports this use.
  • To promote urination
    Mate contains caffeine, which is a diuretic. However, the increased risk of certain cancers likely outweighs any benefits.

  • Research Evidence

    No clinical studies have been conducted to evaluate the usefulness of taking mate. However, several population studies in countries in which mate drinking is very common have found a link between mate and certain cancers. A few of these studies are described below:
    • To test the hypothesis that mate drinkers have high risks of upper digestive and respiratory tract cancers, researchers studied a group of men from Southern Brazil. Compared to men who did not drink mate, those who did had a higher risk of cancer of the mouth and larynx. (As a side note, coffee and tea drinking were not associated with an increased cancer risk). The author concluded that due to a high prevalence of mate drinking in South America, mate tea might be linked to as many as 20% of all cancer cases in this region.
    • Reseachers examined lung cancer rates in heavy mate drinkers compared to light mate drinkers in Uruguay. After adjusting for cigarette smoking (another lung cancer risk), men who were heavy mate drinkers were 1.6 times more likely to develop non-small cell lung cancers compared with light drinkers. In general, the more mate consumed, the greater the risk.
    • In a second study of make mate drinkers in Uruguay, heavy mate drinkers were seven times more likely to develop bladder cancer than light mate drinkers (after adjustments for age, tobacco smoking and social class).

    Warnings

  • High doses and prolonged consumption of mate tea are associated with an increased risk of certain cancers (bladder, oral, esophageal, and lung).
  • 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.
  • This product is regulated by the FDA as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. This product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness.

  • Do Not Take If

  • You have high blood pressure, a heart condition, or anxiety. In general, the warnings about caffeine intake also apply to mate.
  • You are pregnant or breast-feeding.
  • You take benzodiazepines (The effects of benzodiazepines are reduced by the caffeine content in mate).
  • You take beta-adrenergic agonists (The effects of beta-adrenergic agonists are increased by mate).
  • You take clozapine (Mate may alter this drug's effects).
  • You take CNS stimulants (Mate may increase their effects).
  • You take monoamine-oxidase inhibitors (MAO-Is) (Mate can cause hypertensive crisis).
  • You take theophylline (Because mate contains theophylline, it may have additive effects and possibly cause toxicity).
  • You take diuretics (Mate may have an additive effect).
  • You regularly take aspirin (Mate may increase the absorption and blood levels of aspirin; take with caution).

  • Side Effects

  • Headache
  • Insomnia
  • Anxiety
  • Tremor
  • Restlessness and agitation
  • Nausea and vomiting
  • Palpitations
  • One case of liver failure was reported in a heavy mate drinker.

  • Scientific Name

    Ilex paraguariensis

    Common Name

    Yerba mate, St. Bartholomew's tea, Jesuit's tea, ilex, hervea, guyaki Paraguay tea

    Clinical Summary

    Derived from the leaf of the plant. Yerba mate contains caffeine, theophylline, and theobromine, which are responsible for the stimulant activity of this herb. No clinical studies have evaluated its efficacy, although there is extensive experience with each of the previously mentioned chemicals. Epidemiologic studies conducted in the past decade indicate that chronic mate drinkers are at an increased risk of bladder (10), oral, esophageal (8), and lung cancer (9). Frequently reported adverse effects include insomnia, restlessness, agitation, nausea, vomiting, and headache (5). Yerba mate may interact with many prescription medications. Increased or altered activity of beta-adrenergic agonists, CNS stimulants, theophylline, diuretics, and caffeine-containing beverages may occur with concomitant administration (6). Patients with hypertension, cardiac disorders or anxiety, or women who are pregnant or breast feeding, should not consume yerba mate.

    Purported uses

    • Appetite suppression
    • Central nervous system stimulation
    • Depression
    • Fatigue
    • Headaches
    • Pain
    • Promote urination

    Constituents

  • Xanthene alkaloids: 1-2% caffeine, 0.45-0.9% theobromine, 0.05% theophylline
  • Tannins: 4-16% caffeic and chlorogenic acids
  • Amines: Choline and trigonelline
  • Amino acids
  • Flavonoids: Kaemferol, quercetin, and rutin
  • Volatile Oils
  • Other constituents: Ursolic acid (antitumor agent), vitamins B2, B6, C, niacin, pantothenic acid
    (1)

  • Mechanism of Action

    Mate's action is due to its caffeine, theophylline and theobromine activity, which are well documented.

    Warnings

    High doses and prolonged consumption of mate tea are associated with an increased risk of certain cancers.

    Contraindications

    Warnings associated with caffeine apply to mate. Patients with hypertension, cardiac disorders, and anxiety should not consume mate.
    Women who are pregnant or breast feeding should not consume mate.

    Adverse Reactions

    Reported: Insomnia, anxiety, tremor, restlessness, agitation, nausea and vomiting, palpitations, and headache
    (5)

    Herb-Drug Interactions

    Aspirin: Mate may increase absorption and bioavailability.
    Acetaminophen: Pain relief of acetaminophen is increased due to caffeine content in mate.
    Benzodiazepines: Effects of benzodiazepines are reduced by caffeine content in mate.
    Beta-Adrenergic Agonists: Effects of beta-adrenergic agonists are increased by mate.
    Clozapine: Mate may alter effects.
    CNS Stimulants: Mate may increase effects.
    Monoamine-oxidase inhibitors (MAO-I): Mate can cause hypertensive crisis.
    Theophylline: Mate may increase effects and lead to possible toxicity.
    Diuretics: Mate may cause an additive effect.
    (6)

    Lab Interactions

    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, aPTT, or INR.

    Literature Summary and Critique

    Pintos J, et al. Mate, coffee, and tea consumption and risk of cancers of the upper aerodigestive tract in southern Brazil. Epidemiology 1994;5:583-90.
    To test the hypothesis that mate drinkers have high risks of upper aerodigestive tract cancers, data was analyzed from a case-control study in Southern Brazil. The unadjusted relative risk for all upper aerodigestive tract cancers was 2.1. After controlling for tobacco use, alcohol and coffee or tea drinking, the relative risk was 1.6. Most of the excess risk for mate drinkers was for oral and laryngeal cancers. There was no evidence of associations with coffee and tea drinking. The author concluded that due to a high prevalence of mate drinking in South America, mate tea might be linked to as many as 20% of all cases occurring in this region.

    De Stefani E, et al. Mate drinking and risk of lung cancer in males: a case control study from Uruguay. Cancer Epidemiol Biomarkers Prev 1996;5:515-9.
    Mate drinking has been associated with risk of most upper aerodigestive tract cancers. After adjusting for pack years of cigarette smoking, the amount of mate was associated with a 1.6-fold increase in risk for heavy drinkers, compared with light drinkers, with a significant dose-response pattern. Small cell lung cancer showed a significant increase in relative risk for mate amount and mate duration. On the other hand, pulmonary adenocarcinoma was not associated with mate drinking.

    De Stefani E, et al. Black tobacco, mate and bladder cancer. A case-control study from Uruguay. Cancer 1991;67:536-40.
    After adjustments for age, tobacco smoking and social class, a seven-fold increase in risk of bladder cancer was seen among the heavy mate tea drinkers.

    McGee J, et al. A case of veno-occlusive disease of the liver in Britain associated with herbal tea consumption. J Clin Pathol 1976;29:788-94.
    Small amounts of pyrrolizidine alkaloids were recovered from a sample of mate tea, to which the patient was addicted. It seems probable that the consumption of large amounts of mate tea over a period of years was the cause of the hepatic disease.

    References

    1. Bisset N. Herbal Drugs and Phytopharmaceuticals. Stuttgart (Germany): CRC Press; 1994.
    2. Blumenthal, et al. Herbal Medicine, Expanded Commission E Monographs. Austin: American Botanical Council; 2000.
    3. DerMarderosian A, editor. The Review of Natural Products. St. Louis: Facts and Comparisons; 1999.
    4. Newall C, et al. Herbal Medicines: A Guide for Health-Care Professionals, Binghamton: Pharmaceutical Press; 1996
    5. Schulz V, et al. Rational Phytotherapy: A Physicians Guide to Herbal Medicine. Berlin (Germany): Springer; 1998.
    6. Brinker F. Herb Contraindications and Drug Interactions, 2nd ed. Sandy (OR): Eclectic Medical Publications; 1998.
    7. Goldenberg D. Mate: a risk factor for oral and oropharyngeal cancer. Oral Oncol 2002;38:646.
    8. Pintos J, et al. Mate, coffee, and tea consumption and risk of cancers of the upper aerodigestive tract in southern Brazil. Epidemiology 1994;5:583-90.
    9. De Stefani E, et al. Mate drinking and risk of lung cancer in males: a case control study from Uruguay. Cancer Epidemiol Biomarkers Prev 1996;5:515-9.
    10. De Stefani E, et al. Black tobacco, mate and bladder cancer. A case-control study from Uruguay. Cancer 1991;67:536-40.
    11. McGee J, et al. A case of veno-occlusive disease of the liver in Britain associated with herbal tea consumption. J Clin Pathol 1976;29:788-94.

    Last Updated: Jul. 19, 2007
    E-mail your questions and comments to aboutherbs@mskcc.org.
    PrintEmail This Page