- Yerba mate
- St. Bartholomew’s tea
- Jesuit’s tea
- Guyaki Paraguay tea
For Patients & Caregivers
How It Works
Regularly drinking large amounts of mate tea can increase the risk for several types of 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 large amounts of mate regularly is linked to increased risks of developing prostate, lung, bladder, esophageal, or head and neck cancers.
To lose weight
Small studies suggest that a product containing mate helped overweight subjects lose weight and may curb appetite. However, it is unclear if mate alone has these same effects and such results as well as safety of long-term use would need to be confirmed in larger studies. In addition, a large population study indicates that heavy mate drinkers tend to have higher bodyweight.
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
Small studies are mixed on whether mate may have any benefit on bone health.
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.
Do Not Take If
- 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
- Acute hepatitis: In a 21-year old American man, attributed to regular intake of mate tea once or twice daily for 4 months while visiting Argentina (37).
- Liver failure: In an adult woman, linked to chronic long-term use of mate.
- Withdrawal syndrome: Occurred in a newborn caused by a mother’s heavy intake of mate.
For Healthcare Professionals
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.
Studies in humans are limited. One product containing mate was found to delay gastric emptying in overweight patients (5), and other preliminary studies in generally healthy women suggest consumption may have short-term effects on caloric intake and appetite regulation (6). In a large population of heavy mate drinkers, lower lipid levels but higher bodyweight was observed (34).
In a small cross-sectional study, long-term consumption of mate tea was associated with better bone health in postmenopausal women (7), but a more recent case-control study indicates a neutral effect on bone metabolism (35).
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 carcinogenic effects (33), although a meta-analysis found that mate consumed at more than 1 liter daily was associated with increased odds of developing upper aerodigestive tract cancers regardless of the temperature (36).
Mechanism of Action
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 anti-inflammatory 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.
Acute hepatitis: In a 21-year old American man, attributed to regular ingestion of mate tea once or twice daily for 4 months while visiting Argentina (37).
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.