Should You Be Drinking Yerba Mate?Healthy Living
Yerba mate is suddenly everywhere. From the check-out aisle at Whole Foods to the tea selection at your favorite café, “mate” is taking North America by storm.
A species of holly native to areas in Argentina, Bolivia, Uruguay, Paraguay and southern Brazil, Ilex paraguariensis, the Latin name for the yerba mate shrub, grows surprisingly tall to about 45 feet (15 meters). The leaves are dried, sold in tea bags or in bulk, and steeped in similar fashion.
Served hot, cold or as an energy shot, yerba mate is considered to be the new coffee by its fans, who expound its (allegedly) jitter-free health benefits for weight loss, headaches, depression, and fatigue.
Considered the national drink of Argentina, Paraguay, and Uruguay, yerba mate is much more popular than coffee or tea in much of South America. Some estimates suggest it is consumed 6 to 1 over coffee based alternatives in that area of the world.
Even the Pope is a fan of mate, which he apparently drinks every day. He was photographed enjoying it hot from a traditional gourd or “herb cup” (mati in Quechuan, the Native American language spoken primarily in the Andes region) on a goodwill trip to Paraguay.
Yerba Mate Caffeine: A “Clean” Buzz?
Yerba mate definitely contains caffeine and no small amount of it especially if it is steeped for more than just a couple of minutes. So, if you are looking to cut back on the caffeine, switching to yerba mate from coffee is probably not such a great idea. Black tea contains much less caffeine than yerba mate, and green tea even less.
An additional problem with yerba mate is that it does not contain the water soluble amino acid l-theanine. Black, white, oolong, and green tea all contain l-theanine, with green tea having this highest amount per serving. This under-appreciated amino acid significantly slows the absorption of the caffeine and enhances relaxation while at the same time improving cognition (1). It does this by crossing the blood-brain barrier and helping to increase levels of serotonin and dopamine, the body’s feel good chemicals. This boost can assist with both depression and anxiety in sensitive individuals.
The presence of l-theanine in white, black, green and oolong teas probably explains why people who are sensitive to caffeine and coffee can usually enjoy it, but may still experience problems with yerba mate.
Below is the caffeine content of yerba mate, coffee, and tea for comparison purposes. Many people are very surprised to learn how much caffeine yerba mate actually contains.
- Green tea: 25 mg caffeine per cup
- White tea: 28 mg caffeine per cup
- Oolong tea: 37 mg caffeine per cup
- Black tea: 47 mg caffeine per cup
- Yerba Mate: 80 mg caffeine per cup
- Coffee: 100+ mg caffeine per cup
Therefore, if you are looking for jitter-free caffeine, green or white tea would be the best choices due to lower caffeine content and the presence of l-theanine.
Nutritional Value of Yerba Mate
While the jitter-free claims of yerba mate advocates are debatable, the nutritional value is not. Yerba mate boasts an impressive list of vitamins, minerals, and beneficial compounds including B vitamins (B1, B2, B3, B5) and vitamin C; potassium, calcium, manganese, magnesium, iron, phosphorus, zinc; and the beneficial plant compounds quercetin, theobromine and theophylline.
Because of yerba mate’s high antioxidant content, comparisons to green tea, the most widely consumed beverage in the world after water, are common though inaccurate. Elvira de Mejia, associate professor of food science and human nutrition at the University of Illinois at Urbana-Champaign warns that this claim is also misleading.
Green tea and yerba mate actually have very different antioxidant profiles. Green tea is rich in epigallocatechin gallate compounds, while yerba mate’s main antioxidant is chlorogenic acid. Research hints that both of these groups of plant compounds may be beneficial to health by reducing heart disease and cancer risk, but studies are not conclusive by a long shot.
Benefits of Drinking Yerba Mate
Test tube analysis of yerba mate’s antioxidant components has shown reduced stress on heart and liver cells. Protection of DNA from damage in yeast cells and destruction of human liver cancer cells have also been demonstrated. Rat studies have shown yerba mate to improve blood flow through the circulatory system with a beneficial reduction in fat accumulation.
K. Simon Yeung, clinical coordinator and research pharmacist at Memorial Sloan-Kettering Cancer Center in New York City advised caution when drawing conclusions from these types of studies, however. He say that “high antioxidant content doesn’t always translate into a health benefit. . . . We can’t rely on consumption of antioxidants as a safe way to prevent cancer”, for example (2). He points to results discovered in lab and animal studies rarely holding up in human clinical trials.
Anecdotally speaking, given that mate has been enjoyed by traditional cultures for centuries, it is likely that there is at least some benefit to drinking it in moderation although this has yet to be firmly established by human studies.
Research on Adverse Effects of Yerba Mate Consumption
Examination of the human studies on yerba mate consumption as of this writing indicate that moderation is indeed the best policy when it comes to drinking yerba regularly. A comprehensive review of all existing studies on yerba mate conducted in 2003 and published in the journal Head and Neck, suggests that people who regularly drink large amounts of yerba mate were at significantly increased risk for cancer of the esophagus, lungs, mouth, pharynx, and larynx (3).
A “large amount” of yerba mate is defined to be as much as a liter or more per day, not unheard of for those who are attempting to break a soda habit. Concentrated shots of yerba mate would potentially carry similar risk at much lower levels of consumption.
In addition, the peer-reviewed journal Pan American Journal of Public Health examined the role of hot mate in increasing the risk of cancer of the esophagus, larynx, and oral cavity, which seems to be supported by several epidemiological studies from a review of all literature published through August 2008 (4). One of these studies from Uruguay and published in the journal Cancer Epidemiology Biomarkers & Prevention in 2003 found a 300% increased risk of esophageal cancer for the mate drinkers within a group of approximately 800 adults.
More recently, the journal Cancer Epidemiology Biomarkers & Prevention published research from 2008 which found very high levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in processed dry yerba mate leaves and in both hot and cold infusions of mate. The researchers concluded that the results support the hypothesis that the carcinogenicity of mate may be related to its polycyclic aromatic hydrocarbons (PAH) content, including known carcinogens, such as benzo[a]pyrene (5).
Yerba Mate and Kombucha
Hannah Crum, founder of Kombucha Kamp, suggests that yerba mate can be a good choice for brewing the traditional probiotic beverage known as kombucha. The kombucha symbiotic cultures of beneficial bacteria and yeasts (SCOBY) thrive best on a fermentation medium of tea and sugar. However, Crum says that while plain tea and sugar may be best, advanced brewers should feel free to try brewing kombucha with yerba mate as long as there are multiple cultures available for experimentation purposes (each new batch of kombucha yields an additional culture).
The kombucha fermentation process helps to pre-digest the healthful elements contained in yerba mate rendering them more bioavailable (6). This means that these beneficial properties are easier to absorb and metabolize. In addition, some if not most of the caffeine in yerba is used up during the fermentation process as well which is good news for those who are sensitive.
Yerba Mate: Healthy or Not?
Given that yerba mate has been consumed by traditional South American cultures for centuries, moderate consumption either cold or hot can be safely enjoyed unless a caffeine sensitivity is present. In that case, an occasional batch of kombucha brewed with yerba mate can bestow and increase the bioavailability of mate’s beneficial properties while at the same time mitigating the caffeine hit.
However, the scientific literature on yerba mate is very clear: excessive, regular consumption of mate is not wise as the carcinogenic polycyclic aromatic hydrocarbons (PAH) can potentially and significantly increase the risk of carcinomas of the head and neck region if the habit continues unchecked. Thus, a dependence on concentrated forms of the herb such as yerba mate energy shots and other extreme, routine intake should be avoided.
Sarah, The Healthy Home Economist
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