Yerba Mate Benefits & Risks

Yerba mate may boost cognitive and sports performance.
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Yerba mate, Ilex paraguariensis, is a type of holly native to South America that produces glossy, evergreen leaves and red berries. Its leaves and twigs, brewed into a variety of traditional hot or cold beverages, known as mate, are often shared communally, complete with specific customs and rituals, not unlike those that surround tea drinking in some cultures. Mate may offer certain health benefits as well as potential health risks.

Weight and Cholesterol Management

    Yerba mate might help you lose weight and improve your cholesterol levels, according to an animal study published in the December 2009 issue of the journal "Obesity." Animals consumed high-fat diets supplemented with 1 gram per kilogram body weight of yerba mate for 12 weeks. Scientists observed that yerba mate prevented weight gain and decreased levels of low-density lipoprotein, or LDL, the bad form of cholesterol. The herb also decreased glucose levels, in the study.


    A test tube study published in the March 2007 issue of "Obesity" found that yerba mate's antioxidant content compared favorably with that of green tea. Water infusions of green and roasted mate and green tea all showed excellent ability to neutralize free radicals -- reactive molecules that cause cell damage. Its high content of antioxidants might support some of yerba mate's traditional uses, such as promoting weight loss, preventing heart disease, improving liver function and reducing inflammation, according to a study published in a 2013 issue of the journal "Molecules."

Cognitive Benefits

    Yerba mate may keep you alert and improve mental and sports performance, according to New York University's Langone Medical Center, which notes that the herb falls in between black tea and coffee in caffeine content. Researchers of a study published in the April 2010 "Journal of Food Science" found that yerba mate's caffeine content, at 1.01 gram per 100 grams of powder, makes it a significant stimulant. Yerba mate improved some aspects of learning and memory and was ineffective or impaired performance in other areas, in an animal study published in the December 2008 "Journal of Ethnopharmacology." Scientists gave animals doses of yerba mate immediately before challenging them with mazes and other tests of spatial and social memory. They found that social memory improved when moderate doses of yerba mate were combined with very low doses of caffeine. However, high doses of yerba mate alone impaired performance on a maze test.


    Compounds in yerba mate may increase your risk for certain forms of cancer, according to a study published in a 2011 issue of "Asian Pacific Journal of Cancer Prevention." The study, which included more than 13,000 participants over 14 years, found more frequent occurrence of throat, stomach, lung, cervical, prostate, bladder and kidney cancers in people who reported drinking yerba mate for longer periods of time. Researchers noted that mate contains high levels of certain naturally occurring cancer-causing substances. Risk also increased in those who consumed mate hot versus warm. Yerba mate may also interact with stimulant drugs, such as those used to treat attention-deficit disorder, or ADD, and drugs for insomnia or anxiety.

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