Yerba Mate Tea Benefits and Risks

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yerba mate tea
man drinking yerba mate tea. Michael Hanson/Aurora/Getty Images

Yerba mate (Ilex paraguayenis) is a tree native to the rainforests of South America. A member of the holly family, the tree produces leaves and stems that have long been used to make tea in Brazil, Paraguay, and Argentina. Consumed as a beverage, yerba mate tea (often simply called "yerba mate") is also used in traditional medicine to treat various health problems.


Yerba mate proponents claim that the tea can help with these health concerns:

Health Benefits

The Natural Medicines Comprehensive Database scores numerous studies on herbs and supplements and finds no studies that have sufficient evidence to rate its effectiveness for any condition. Existing studies weakly suggest that the tea and/or yerba mate extract may be useful for the following:

1) Weight Loss

In small 2001 study of 47 healthy overweight adults, researchers found that taking a mixed herbal preparation (containing yerba mate, guarana, and damiana) three times daily for 45 days induced significant weight loss. The herbal blend also helped participants feel full more quickly while eating.

A 2009 study on mice found that yerba mate might modulate in expressing several obesity-related genes and, in turn, produce a potent anti-obesity effect.

2) Cardiovascular Problems

Yerba mate extract may help attenuate heart muscle dysfunction resulting from ischemia (a condition that occurs when a blockage in a coronary artery reduces blood flow to the heart), according to a 2005 study on rats.

3) DNA Repair

A study published in 2008 found that yerba mate helped neutralize free radicals and protect mice from DNA damage, a hallmark of cancer and other diseases.


Some studies have linked chronic consumption of yerba mate with an increased risk of bladder, esophageal, lung, and head and neck cancers. Although researchers have yet to determine how or why yerba mate might raise cancer risk, there's evidence that steeping the tea at high temperatures may promote absorbing certain carcinogenic compounds found in the plant.

Side Effects

In some cases, consumption of yerba mate may trigger adverse effects such as anxiety, insomnia, nausea, and headache.

Due to yerba mate's caffeine content, people with high blood pressure, heart disease, and anxiety should avoid the tea or extract.

Supplements haven't been tested for safety and because dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label. Also, keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. You can get tips on using supplements, but if you're considering the use of yerba mate, talk with your primary care provider first. Self-treating a condition and avoiding or delaying standard care may have serious consequences.

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Article Sources
  • Arçari DP, Bartchewsky W, Dos Santos TW, Oliveira KA, Funck A, Pedrazzoli J, de Souza MF, Saad MJ, Bastos DH, Gambero A, Carvalho PD, Ribeiro ML. "Antiobesity Effects of yerba mate Extract (Ilex paraguariensis) in High-fat Diet-induced Obese Mice." Obesity 2009 May 14.
  • Loria D, Barrios E, Zanetti R. Cancer and yerba mate consumption: A review of possible associations. Revista panamericana de salud pública = Pan American journal of public health. 2009;25(6):530–9.
  • Miranda DD, Arçari DP, Pedrazzoli J Jr, Carvalho Pde O, Cerutti SM, Bastos DH, Ribeiro ML. "Protective effects of mate tea (Ilex paraguariensis) on H2O2-induced DNA damage and DNA repair in mice." Mutagenesis. 2008 23(4):261-5.
  • Yerba mate: MedlinePlus supplements.