Yerba mate tea may be the new coffee, but you and your patients should know about the possible risks.

By Julia Ries | Fact-checked by Davi Sherman
Published September 27, 2023

Key Takeaways

  • Yerba mate tea, a long-popular beverage in Latin and South America, is gaining global recognition for its numerous health benefits, including gut health.

  • Yerba mate tea is safe for most healthy adults when consumed moderately due to its caffeine content.

  • However, excessive consumption can pose risks, including exposure to polycyclic aromatic hydrocarbons (PAHs) and potential links to certain cancers

While yerba mate tea has been around for centuries, it has recently captured worldwide interest for its health benefits. The tea has long been popular in Latin and South America, including in Uruguay, Paraguay, Argentina, and parts of Brazil.[][]

Yerba mate tea is made by steeping dried, crushed leaves of the yerba mate plant, a type of evergreen tree, in hot water. The leaves can be resoaked up to seven times without losing their nutritional value, making it a common substitute for coffee. Nowadays, prepackaged bottles of cold yerba mate tea can be readily found at grocery stores.[]

Historically, yerba mate tea has been used by Indigenous people for medical purposes, as the tea can have powerful cardiovascular, gastrointestinal, and neurological benefits. It’s rich in caffeine, making it a sought-after energy booster. Though the tea has wide-ranging health benefits, you don’t want to overconsume it: in extremely high amounts, it can trigger side effects and potentially increase the risk of some types of cancer. For the average person, however, yerba mate tea is thought to be a healthy beverage that can help heal and protect the heart, gut, brain, and lungs.[]

“For people who enjoy a caffeinated beverage, [yerba mate tea] is stimulating, with less of a ‘crash’ than coffee may cause. It contains a number of nutrients, including essential fatty acids, and, like other teas, is rich in antioxidants,” Katie Stage, ND, RH (AGH), FABN, a naturopathic physician, registered herbalist, and Director of Therapeutics Division at Sonoran University, tells MDLinx

Yerba mate tea promotes brain, heart, and gut health

Yerba mate tea has been marketed as a health drink. It’s packed with vitamins and minerals, such as vitamin C, vitamins B1, B2, B6, potassium, calcium, magnesium, and trace iron, and essential fatty acids, says Stage.[][]

Reports have shown that yerba mate is used as a medicine for anxiety and fatigue, supporting metabolism and stimulation of the nervous system. The plant is also known for its antioxidants, like polyphenols and terpenes, which have positive cardiovascular and anti-inflammatory effects. These antioxidants “help to promote health by fighting free radicals, decreasing inflammation [and] cholesterol, increasing energy, and reducing the risk of disease,” says Amy Shapiro, MS, RD, Founder and Director of Real Nutrition NYC.[][]

The list of health benefits continues: Evidence suggests that yerba mate tea may also prevent infections caused by bacteria, parasites, and fungi, particularly in the large intestine. The high levels of caffeine in a cup of yerba mate tea may boost alertness and reaction time and improve short-term memory. The tea has also been touted as a weight loss tool, which Stage says is due to the fact that it decreases appetite, speeds up metabolism, and combats the growth of fat cells.[][]  

It’s safe to drink—in small doses

Yerba mate tea is heavily caffeinated. “One cup of tea does contain a comparable amount of caffeine to one cup of coffee—more caffeine than a typical cup of black or green tea,” says Stage. For reference, 200 milliliters of yerba mate tea, or about one cup, contains about 71.8 milligrams of caffeine, while the same amount of cappuccino coffee contains approximately 86.8 mg of caffeine. According to Shapiro, most healthy adults can consume yerba mate tea with no health risks.[]

Yerba mate does contain small amounts of polycyclic aromatic hydrocarbons (PAHs), which can cause toxicity in high doses. The most common routes of human exposure to PAH include smoke (from tobacco, for example), environmental contamination, and exposure to chemicals in the workplace. Diet is also a major source of PAH exposure: Certain foods may be contaminated with the compounds, either from the environment or from certain processing methods.[][]

Yerba mate tea, best known for its high caffeine content and health benefits, is also believed to carry a risk of PAH exposure. Studies have investigated the levels of PAHs in mate leaves, but the data is mixed. Some researchers say that although the leaves have high amounts of PAHs, mate infusions contain low amounts of PAHs; however, repeated soaking of the leaves could increase the amount of PAHs a person is exposed to.[][] 

Other studies have linked the tea to various types of cancer, such as those of the esophagus, bladder, and lungs. That said, evidence suggests that it’s unclear how much mate may contribute to cancer or if the association may also be explained by other lifestyle behaviors that go hand-in-hand with drinking mate tea, such as smoking cigarettes. “It is important to note that yerba mate also contains many compounds that fight cancers, so this may not be as alarming as it sounds,” says Shapiro.[] 

How to drink Yerba mate tea safely

A cup of yerba mate tea here and there likely won’t do you any harm. “An occasional cup of tea made from fresh leaves does not confer any more PAHs than a typical diet,” Stage says.

High doses of hot tea are believed to increase the risk of PAH exposure, Stage notes, as hot beverages can irritate the esophagus and promote the extraction of PAHs. “Drinking the tea warm or cool—instead of hot—would further decrease the risk,” Stage says. The best way to drink yerba mate tea is in cold brew form, experts say. This maximizes the essential fatty acids you’ll consume and minimizes the risks of PAH exposure, according to Stage.[] 

It’s also important to know your caffeine tolerance. As mentioned, yerba mate tea contains more caffeine than other teas and coffee. Some may find that the caffeine in yerba mate tea can cause an upset stomach, trouble sleeping, nervousness, and a fast heartbeat. Anecdotally, some find that the tea causes less of a crash than coffee. “Many people find Yerba mate to provide a more sustained experience of mild stimulation compared to that of coffee,” Stage says.[]

Due to yerba mate tea’s potential risks, it’s not recommended for pregnant people, as it may increase the risk of miscarriage and low birth weight of the baby. It’s also not advised for people sensitive to caffeine and those taking monoamine oxidase inhibitor medications, as it can lead to harmful interactions, says Shapiro.[][]

As with many things, in moderation, yerba mate tea can be beneficial; in excess, however, it may lead to unwanted side effects and potentially increase the risk of cancer. In general, the benefits far outweigh the risks: “It is minimally processed, it is an easy way to increase your intake of antioxidants, it contains less caffeine than coffee, and it can help you to perform, be more energetic, delay cognitive decline, and decrease the risk of a variety of healthy conditions,” Shapiro says.

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