erva mate

Is Yerba mate tea healthy or harmful?


Yerba mate tea has been popular among South American cultures for centuries, but only in the past two decades have serious scientific studies been done to determine if this drink is healthy or not.

The hundreds of studies conducted in North and South America have given mixed results—some conclude it is healthy and some say it is dangerous, increasing the risk of esophageal and other cancers. Let’s try to make some sense of these studies and present some ways that should make mate drinking safer and healthier.

Mate tea is a complex substance, full of hundreds of chemical compounds, including caffeine, and theobromine and theophylline; the compounds found in green and black teas and dark chocolate that act as mild stimulants. Many studies point to the high concentration of polyphenol and flavonoid antioxidant compounds in mate, different than those found in tea or red wine. Mate is also full of minerals such as copper, manganese, potassium, iron, and zinc, as well as vitamins B1, B2, and C.

Foods high in antioxidants such as mate are believed to prevent cancer and cardiovascular disease, and the stimulants found in mate have shown beneficial effects on gastric emptying. Meaning, the stomach empties slower after drinking mate, so a person should feel satiated longer and eat less. This, along with some fat burning properties in the mate chemicals, has spawned a number of weight loss aids containing mate that sell particularly well in North America.

Indeed, there are some good studies to suggest mate might help at least in short-term weight control, and other studies suggest that mate helps protect the liver from damage. Some research has shown that postmenopausal women mate drinkers have somewhat stronger bones, and other good studies show that mate drinkers have lower cholesterol and triglyceride levels. Beyond all these possible chemical advantages, the rituals surrounding mate drinking may have important psychological benefits, helping keep friends physically connected in this increasingly virtual world.

On the other side, a number of well-done studies have shown a significantly higher risk of head and neck, esophageal, lung, prostate, and urinary cancers in people who consume large quantities of hot mate over many years. This is perplexing considering the high quantity of antioxidants in mate, which should protect against cancer, but consistently, studies have shown a higher risk of these cancers in mate drinkers.

It is believed that it might not be the mate itself increases the cancer risk, but that mate is typically drunk hot. The heat might be reacting with other chemicals, perhaps contaminants, in mate (especially polycyclic hydrocarbons similar to those found in grilled, charred meats) that become carcinogenic. In processing, mate is often dried over wood fires; potentially adding harmful chemicals to the final product.

Another confounding factor is that many times the mate drinkers who develop these cancers have also been cigarette smokers or heavy alcohol drinkers. The highest risk of cancer in mate users seems to be those who also smoke and/or drink alcohol excessively.

The bottom line

Is there a way to use mate to obtain the benefits while lowering the potential risks? Consider the following: don’t drink it hot, but rather warm or cooler; don’t drink it every day or in large quantities; buy only organic, air-dried (as opposed to fire dried) mate; make sure you eat lots of fruits and vegetables which might counter the cancer-causing effects; and keep your mouth and teeth in good condition, since bad oral nutrition contributes to head and neck cancers. Finally, if you smoke cigarettes or drink lots of alcohol, mate is probably not a good choice. Listed below are several comprehensive scientific references if you want to investigate mate further.

Yerba Mate Tea (Ilex paraguariensis): A Comprehensive Review on Chemistry, Health Implications, and Technological Consideration (Food Science)

“Mate”, Memorial Sloan Kettering Cancer Center, New York

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Esta postagem também está disponível em: Portuguese (Brazil)

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