Mat

In the test tube, mate has shown effects that suggest possible value for reducing cancer risk. 1-3 However, these findings are far too preliminary to rely upon; in fact, there is stronger evidence that mat could under certain circumstances increase risk of cancer (see Safety Issues ). Other proposed benefits of mat also largely lack foundation. One study found that an extract of mate could help slow glycation, a metabolic side effect of diabetes. 4 These findings have been used to claim that mat is healthful for people with diabetes . However, this study did not involve people with diabetes; it involved chemicals in a test tube. Tens of thousands of substances show benefits in the test tube that fail to translate into real life; it is greatly premature to claim that mat is helpful for people with diabetes based on these exceedingly preliminary findings. Similarly weak evidence hints that mat might increase fat metabolism, 5 and on this basis mat has been proposed as a weight-loss agent . However, there are no published human studies of mat that show any weight loss benefit. One small double-blind, placebo-controlled study evaluated an herbal preparation containing mat combined with guarana(Link tonew article) and damiana . 6 The herbal mixture appeared to cause participants to feel full more quickly during a meal, and to continue to feel full for longer after the meal; this led to modest, short-term weight loss. However, it is not clear to what extent the mat in this product played a role.

Another study found that mat might increase bile flow and speed the action of the intestines 7 ; these reported effects, even if real, do not indicate any particular health benefit. Although some mat proponents attempted for many years to maintain that mat does not contain caffeine (supposedly it contained a chemical called mateine, which, in fact, does not exist), mat does in fact contain caffeine. Depending on how it is brewed, mat tea contains somewhat more caffeine than black tea and slightly less caffeine than coffee. Based on this caffeine content, mat would be expected to enhance mental function and improve sports performance . DosageA typical dose of mat is 310 grams dried herb per cup. Concentrated extracts are also available. These should be taken according to label instructions. Safety Issues As a widely consumed beverage mat is generally assumed to be entirely safe. However, this may be an incorrect assumption. Numerous studies have found associations between high consumption of mat in South American and increased rates cancer of the esophagous, mouth, throat, and larynx. 8-10 It is widely stated that this increased risk is entirely due to the practice of drinking mat at very high temperatures. However, the underlying evidence is not so clear-cut. The data actually suggest that at least some of this increased risk is be due to the mat itself, rather than the temperature at which it is consumed. 10 In addition, mat consumption has also been associated with increased risk of kidney and lung cancer, which would not be expected to be influenced by beverage temperature. 11,12 Finally, there is some direct evidence that mate has carcinogenic effects. 13 Putting all this information together, it does appear that mat is at the very least slightly carcinogenic. However, so is charred hamburger; moderate use of mat is not likely to significantly increase cancer risk.

Other potential problems with mat relate to its caffeine content. Potential side effects of caffeine include heartburn, gastritis, insomnia, anxiety, and heart arrythmias (benign palpitations or more serious disturbances of heart rhythm.) 14 All drug interactions that can occur with caffeine would be expected to occur with mat as well (see next section). Maximum safe doses have not been established in pregnant or nursing women, young children, or people with severe liver or kidney disease. Interactions You Should Know About If you are taking: MAO inhibitors : The caffeine in mat could cause dangerous drug interactions. Stimulant drugs such as Ritalin: The stimulant effects of mat might be amplified. Drugs to prevent heart arrythmias or treat insomnia , heartburn , ulcers , or anxiety : The caffeine in mat might interfere with their action. References 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 . 2005;53:196673.

Ramirez-Mares MV, Chandra S, de Mejia EG, et al. In vitro chemopreventive activity of Camellia sinensis , Ilexparaguariensis and Ardisia compressa tea extracts and selected polyphenols. Mutat Res . 2004;554:5365. Chandra S, De Mejia Gonzalez E. Polyphenolic compounds, antioxidant capacity, and quinone reductase activity of an aqueous extract of Ardisia compressa in comparison to mate ( Ilex paraguariensis ) and green ( Camelliasinensis ) teas. J Agric Food Chem . 2004;52:35839. Lunceford N, Gugliucci A. Ilex paraguariensis extracts inhibit AGE formation more efficiently than green tea. Fitoterapia . 2005 May 12 [Epub ahead of print] Martinet A, Hostettmann K, Schutz Y, et al. Thermogenic effects of commercially available plant preparations aimed at treating human obesity. Phytomedicine . 2000;6:2318. Andersen T, Fogh J. Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients. J Hum Nutr Diet . 2001;14:24350. Gorzalczany S, Filip R, Alonso MR, et al. Choleretic effect and intestinal propulsion of 'mate' ( Ilex paraguariensis ) and its substitutes or adulterants. J Ethnopharmacol . 2001;75:2914.

Goldenberg D, Lee J, Koch WM, et al. Habitual risk factors for head and neck cancer. Otolaryngol Head Neck Surg . 2004;131:98693. Sewram V, De Stefani E, Brennan P, et al. Mate consumption and the risk of squamous cell esophageal cancer in Uruguay. Cancer Epidemiol Biomarkers Prev . 2003;12:50813. Goldenberg D, Golz A, Joachims HZ, et al. The beverage mate: a risk factor for cancer of the head and neck. Head Neck . 2003;25:595601. De Stefani E, Fierro L, Mendilaharsu M, et al. Meat intake, 'mate' drinking and renal cell cancer in Uruguay: a case-control study. Br J Cancer . 1998;78:123943. 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 . 1996;5:5159. Leitao AC, Braga RS. Mutagenic and genotoxic effects of mate ( Ilex paraguariensis ) in prokaryotic organisms. Braz J Med Biol Res . 1995;27:15175. Cannon ME, Cooke CT, McCarthy JS. Caffeine-induced cardiac arrhythmia: an unrecognised danger of healthfood products. Med J Aust . 2001;174:5201.

Last reviewed October 2007 by EBSCO CAM Review BoardPlease be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.