- Yerba mate
- St. Bartholomew’s tea
- Jesuit’s tea
- guyaki Paraguay tea
For Patients & Caregivers
Bottom Line: 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. In addition, drinking high doses of mate tea can increase the risk for several types of cancers.
- 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 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.
- Increased risks for various cancers
Multiple population studies note a link between long-term mate use and various types of cancer. In some cases this link is direct, while in other cases, the link may be less direct or also associated with other factors.
- Weight Loss / Appetite Control
Two small studies suggest that a specific mate supplement may curb appetite and aid in weight loss, but larger studies are needed to confirm this effect as well as confirm safety.
- Bone health
A study compared the bone density of 146 women after menopause who drank more than 4 cups of mate for over 4 years with 146 women who did not drink mate. All women were chosen from a program they participated in for “bone-thinning” prevention and treatment. Bone mineral density appeared to be higher in the neck and lower back regions in the women who drank mate. Although this seems to suggest that mate may protect against bone loss with long-term use, such a benefit may be canceled out by the increased risk for various cancers that has been noted with chronic mate use. Also, this was a small group of women in a special program in a specific region, so these findings would not necessarily relate to the general public.
- High doses and prolonged use of mate tea are linked to increased risk of certain cancers (prostate, bladder, oral, esophageal, lung, and head and neck).
- 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.
For Healthcare Professionals
Mate is a plant native to South America. It is popularly 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 would be 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). In addition, this risk appears to be a additive when combined with chronic alcohol or tobacco use (20).
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 in mate are largely responsible for its stimulatory effects. 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.
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.
Deneo-Pellegrini H, et al. Food groups and risk of prostate cancer: a case-control study in Uruguay. Cancer Causes Control. 2012;23:1031-1038.
This case-control study evaluated 326 men age 40–89 y with verified and mostly advanced prostatic adenocarcinomas between 1996 and 2004. Both cases and controls answered a detailed questionnaire including sociodemographic variables, occupational exposures, family cancer history, tobacco history, alcohol consumption, and diet. The food-frequency questionnaire included 64 food items, representing the typical Uruguayan population diet. A total of 27 food items, including mate, were analyzed for their potential relationship with prostate cancer. A direct, positive association with risk of prostate cancer was found for mate consumption (OR, 1.96; 95 % CI, 1.17–3.31, P for linear trend =.005), while coffee, tea, and soft drinks were not associated with increased risks. This study echoes other epidemiologic studies that have shown increased risks of various cancers with chronic mate consumption.
Harrold JA, et al. Acute effects of a herb extract formulation and inulin fibre on appetite, energy intake and food choice. Appetite. 2013;62:84-90.
A patented herbal extract containing yerba mate, guarana and damiana (YGD) was evaluated alone, or in combination with soluble fermentable fibre (SFF) in this double-blind, placebo-controlled, crossover study. The fibre used was chosen because of previously observed effects on appetite. Participants were 58 normal-to-slightly overweight women who consumed a prescribed breakfast (496 kcal) followed 4h later by an ad libitum lunch. Fifteen minutes before meals, subjects took 3 YGD tablets and SFF (5g in 100mL water), YGD and water (100 mL), 3 placebo tablets and SFF, or 3 placebo tablets and water. Appetite was assessed using visual analogue scales, and energy intake was measured at lunch. Significant reductions in food and energy intake were observed with YGD (59.5g, 16.3%; 112.4kcal, 17.3%) and SFF (31.9g, 9.1%; 80kcal, 11.7%) compared with conditions where products were absent. Lowest intakes (gram and kcal) were in the YGD+SFF group. Significant reductions in AUC hunger and AUC desire to eat were also observed with the YGD+SFF combination. These preliminary data suggest that YGD can produce short-term reductions in caloric intake and the effect can be augmented by adding SFF. However, more study is needed to confirm actual efficacy as well as safety with long-term use.
Conforti AS, et al. Yerba mate (Ilex paraguariensis) consumption is associated with higher bone mineral density in postmenopausal women. Bone. 2012;50:9-13.
In this retrospective study among participants in a program for osteoporosis prevention and treatment, 146 postmenopausal women who drank ≥1 L of mate tea daily for ≥4 years were identified and matched by age and time since menopause with women who did not drink mate. Bone mineral density (BMD) was measured in both groups by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and femoral neck. Lumbar spine BMD in the mate group was 9.7% higher (0.952 g/cm2 vs 0.858 g/cm2: P<.0001); femoral neck BMD was 6.2% higher (0.817 g/cm2 vs 0.776 g/cm2; P=.0002). In multiple regression analysis, mate tea drinking was the only factor other than BMI that showed a positive correlation with BMD at both lumbar spine (P<.0001) and femoral neck (P=.0028). These results are a preliminary suggestion that long-term ingestion of mate may protect against bone loss, but confirmatory studies are needed. In addition, this benefit may be offset by the association that long-term chronic mate use has with increased risks for various cancers.