Yerba mate (pronounced matay) has been valued in South America for centuries, long before Columbus set off on his epic journey. A hot “tea” was made from the leaves of a holly tree (Ilex paraguariensis) and it was purported to have healing properties. It has remained popular in countries like Paraguay, Uruguay, Argentina, Brazil and Chile. Now, yerba mate is gaining converts in North America as well. Here is a recent question:
Q. My friend introduced me to yerba mate, a tea from South America. He said that if he drinks it in the afternoon he feels alert but not jittery.
What can you tell me about yerba mate? I have high blood pressure and I try to stay away from caffeine.
A. Yerba mate comes from a South American tree in the holly family. It has long been a traditional beverage for tribes in the region. In Argentina and Uruguay drinking mate is often a social event.
The leaves contain caffeine, theobromine and theophylline, and all appear in the brew. The caffeine content is between tea and coffee. It has less theobromine than cocoa. The drink is rich in polyphenols that might have health benefits, but there aren’t many studies.
One small clinical trial showed that yerba mate did not affect blood pressure or heart rate (Phytomedicine, Oct., 1999).
We suggest you measure your blood pressure before and after drinking a cup to see how it affects you.
Many years ago (Nov, 1997) we received a somewhat similar question:
Safer? Healthier than Coffee?
Q. Some years ago, I lived in Argentina and came to know their national drink, yerba mate. I was told it had all kinds of nutritional benefits. The gauchos (Argentine cowboys) used to live on mate and meat.
I keep some around and have it a couple of times a week instead of tea or coffee. Is it really much better health-wise than those beverages? Should I be taking it more often?
Yerba mate has about the same amount of caffeine as a small cup of coffee. It does have some vitamins and minerals including C, B1, nicotinic acid, potassium, magnesium and manganese, though this does not make it a health drink. There is concern that people who drink it frequently may be at higher risk of cancer of the esophagus.
After reviewing what we wrote about esophageal cancer and yerba mate 18 years ago, we thought we would do some digging to see if that concern still exists. An article in the journal Cancer Epidemiology, Biomarkers & Prevention (Jan, 2014) provides the context for their analysis:
“[Mate] is a non-alcoholic beverage consumed throughout southern South America, and is gaining broader acceptance in other areas of the world as a tea and dietary supplement based on purported health benefits, such as lowered cholesterol levels, improved cardiovascular health and obesity management. However, studies have linked maté consumption with esophageal squamous cell carcinoma (ESCC), as well as cancers of the oral cavity, pharynx, larynx, lung, kidney and bladder. The International Agency for Research on Cancer (IARC) designated hot maté drinking a probable human carcinogen. Proposed carcinogenic mechanisms include thermal injury from repeated high temperature exposure and exposure to polycyclic aromatic hydrocarbons (PAHs), a production-related contaminant.”
The investigators analyzed data from two epidemiological studies and concluded that the more mate tea people consumed the greater the risk for developing esophageal cancer. This association seemed to be greater the hotter the tea. The scientists attributed this added risk to “thermal injury.”
What are we to make of this report? Epidemiological studies can only suggest an association. They cannot prove there is a problem. Nevertheless, it does appear that drinking a lot of extremely hot mate tea could be problematic. One cup of warm tea now and then may not pose much of a problem, but drinking very hot yerba mate regularly is probably not a good idea.
Have you ever tried yerba mate? What does it taste like? Share your experience below and please vote on the article by choosing a star at the top of this page.