The Health Benefits of Yerba Mate
Can Yerba Mate help you lose weight? How much caffeine is Yerba Mate? Is it safe to drink during pregnancy? Can Yerba Mate cause cancer? Can it help prevent it? Is yerba high in antioxidants? What are Yerba Mate’s side effects?
The Ilex plants have been drunk for many centuries, and along the way there have been many claims, from helping women with fertility, to purify the body, enhance physical performance, and reducing fat.
In particular, and according to Javier Ricca (2012) Yerba Mate was used against a number of ailments since the 15th Century. Boiled mate (Mate cocido) was given to newborns to help to release the meconium, but also as cures for pneumonia and scarlet fever and to mitigate hair loss, burns, and even headaches.
Can Yerba Mate help you lose weight? Can it help lose fat? Can it help reduce ‘bad’ cholesterol?
Yes, yes and yes. - But this just applies for an unsweetened mate.
A 2002 Danish study stated that an herbal preparation that included Yerba Mate, Guarana and Damiana ‘delayed gastric emptying, reduced the time to perceived gastric fullness and induced significant weight loss over 45 days in overweight patients’.
A Korean 2012 research done on mice determined that ‘Yerba Mate treatment affects food intake, resulting in higher energy expenditure, likely as a result of higher basal metabolism’. With a faster metabolism, the energy is spent faster, which can lead to losing weight. As other studies have explained, Mate’s effect on weight loss is probably due to the caffeine concentration, which also helps delay the absorption of fat.
Another study was done in Korea in 2015 with men and women with obesity. The results showed that after consuming yerba mate capsules for three weeks, the values of body fat mass and percent body fat decreased significantly, without producing significant adverse effects.
A 2012-2014 research done in Argentina showed that daily consumption of mate reduced the total cholesterol and LDL ("The bad") cholesterol by almost 12% in the course of 12 weeks. The research was done in two groups: one drinking approx. 50g of yerba mate (with 500 ml of water), and the other one, with double that amount. The results showed that in both cases the reduction of TC and LDL was considerable.
How much caffeine is in Yerba Mate?
Needless to say, it depends on the type of yerba mate. However, in general terms, yerba mate has less caffeine than coffee but more than tea. Some of the brands, like Meta Mate, clarify it in their labels, so you can buy based on your preference.
While coffee has approx. 95mg per cup, studies have found that there is approx. 78 mg of caffeine per cup of mate. A cup of mate, according to Mazzafera, is 150 ml, so by drinking 0.5 L of water, you would be having 260 mg of caffeine (almost 3 cups of coffee).
What are Yerba Mate’s side effects?
Due to its content of caffeine if drunk in high doses it could induce insomnia, tachycardia, gastritis, and nausea.
The corporation WebMD states yerba mate could be possibly unsafe for people who suffer from alcoholism, anxiety disorders, bleeding disorders, heart conditions, diabetes, diarrhea, glaucoma, high blood pressure, irritable bowel syndrome. If in doubt, check with your doctor.
Is it safe to drink during pregnancy?
Because of its caffeine content, it should be monitored - and it should be consulted with a doctor.
There are different recommendations in terms of what is the limit of caffeine per day during pregnancy (it varies between 200 and 300 mg). This includes mate but also coffee, tea, sodas, etc.
A 2005 study showed that drinking mate on a daily basis whilst being pregnant had ‘no harmful effect on intrauterine growth or duration of pregnancy’. However, an Uruguayan study done in 2014 concluded that ‘The consumption of more than 300 mg a day is associated with a higher risk of small newborns for their gestational age.’
It is also encouraged to avoid the first brews (as those are higher in caffeine) or have mate cocido (boiled mate). As mentioned before, different types and brands of yerba mate have different caffeine content.
Is yerba high in antioxidants? Is it anti-inflammatory?
Yerba mate contributes tremendously to the overall antioxidant intakes - is higher in antioxidants than green tea! In fact, a 2018 study even showed that its antioxidant properties were also present in used yerba.
Ferreira Cuelho and others also sustain that yerba mate is antioxidant, anti-inflammatory, antimutagenic, antidiabetic and lipid-lowering activities, making it beneficial to those on chronic diseases with inflammatory components, diabetes, and lipid metabolism disorders.
Can Yerba Mate cause cancer?
No, if it is drunk at the right temperature.*
In 1991, the International Agency for Research on Cancer (IARC) classified yerba mate hot infusions ‘probably carcinogenic to humans (Group 2A)’ but that the ilex paraguariensis was noted as not classifiable (Group 3).
Some studies in the late 90s and early 2000s suggested an association between the consumption of yerba mate and the risk of developing certain cancers - mainly esophageal, and oral. However, other specialists suggest that there are other factors, such as a high cigarette and alcohol consumption, that could affect said results.
Newer studies showed a stronger relationship between a high temperature of a drink (being mate, tea or coffee) and oral cancer than of the drink itself. The new IARC evaluation has stated that drinking very hot* drinks have been associated with a higher risk of oesophageal cancer (Group 2A). This statement includes any hot drink, and it is not particular to yerba mate. In fact, according to the IARC, drinking mate with warm and cold water is not associated with oesophageal cancer (Grupo 3).
We've also covered here on the blog separately whether smoked yerba mate can cause cancer.
*The IARC recommends drinking beverages under the 65°C.
Can yerba mate help prevent cancer?
That would be a bold statement and one that requires a lot more research.
Having said that, various studies have been done around the carcinogenic properties of Yerba Mate (Yamamoto in 1997 and Heck and De Mejia in 2007 for example). Such studies have shown that compared with other teas (such as green tea), yerba mate has higher cytotoxicity for cancer cells (“high anticancer potential”).
Research on yerba mate is relatively new compared research on coffee or tea. However, it is clear that science is just catching up with the amazing properties of Ilex paraguariensis.