No one likes to talk about this.
If you bring up your worries about cancer to someone who’s passionate about yerba mate, you’ll most likely aggravate them. Not because you’re hitting them with the cold hard truth, but because they correctly assume you don’t know the full picture and are too overly concerned.
You see, most long-time yerba mate drinkers get this question all the time.
Does yerba mate cause cancer? Isn’t it unhealthy? Is It safe to drink?
They get this so often they’re even tired of hearing it.
I never wanted to talk about this either because I’m in no position to tell you what’s safe and unsafe to drink, or what to believe or not to believe. And frankly, it’s too much to dive in to. But because so many people are talking about it, I’ll only put in my two cents and my current understanding of the matter.
So to begin, let’s lay out why people are worried in the first place…
Why Does Yerba Mate Cause Cancer?
Years ago, studies showed an association between yerba mate and increased risk of esophageal cancer. The studies, however, were flawed. Some subjects were already ill, some consumed alcohol, and some smoked tobacco.
Despite this though, they were still able to find a possible relation between yerba mate and cancer.
Because yerba mate is smoke-dried (over burning wood) when processed, they believed this to be the cause.
This smoking method imparts a carcinogenic chemical known as PAH (polycyclic aromatic hydrocarbons) to the leaves that can be released when brewing. And studies have found a number of yerba mate brands to contain a high content of it. Any brand that participates in this drying method (which is the majority), most likely contain PAHs.
Naturally, this worries people.
But I’ll tell you why it doesn’t worry me (and why it shouldn’t worry you)…
Yerba Mate PAH Level
Believe it or not, there’s a high chance you’re already exposed to this carcinogenic compound – PAH – on a daily basis, without even knowing it.
If you smoke, you’re exposed to PAH.
If you eat barbecued, smoked, grilled, or roasted food, you’re exposed to PAH.
If you eat fruits, vegetables, and grains, you’re exposed to PAH.
Even if you use soap or shampoo, you’re potentially exposed to PAH.
PAH is ubiquitous and can be found in the air, water, and soil in varying degrees. To try to avoid it is nearly impossible. And to avoid yerba mate, for this sole reason, is laughable.
Because you know what else contains PAH?
Coffee of all roasts, white tea, green tea, black tea, and red tea.
Should we then avoid these drinks too even though many studies have shown them to be helpful in preventing disease and lowering death rates?
Probably not.
Then why only be concerned with yerba mate containing this carcinogen?
Now to clarify, none of this is to say PAH is safe or healthy. It’s not. But it’s also not the main reason why yerba mate seems to be closely associated with cancer.
This is…
Yerba Mate And Cancer
What studies have found to be the main cause of cancer regarding yerba mate is the temperature it’s consumed at – not the yerba mate itself.
I repeat: it’s the water temperature, not yerba mate.
Native countries in South America such as Argentina and Uruguay, are known to drink mate at hot temperatures in the 158-185ºF (70-85ºC) range. Consuming fluids of any kind at these temperatures seem to increase the risk of esophageal cancer.
And considering how much (1-3 liters a day) and how often (daily) the average South American drinks mate, it’s reasonable to see why esophageal cancer seems to be a major health problem, more specifically in Uruguay.
However, contrary to all this, a more recent article in January 2019 by Memorial Sloan Kettering Cancer Center states,
There has never been solid evidence that drinking hot liquids alone will increase esophageal cancer risk.
If this is the case, then the only cancer risk yerba mate seems to pose is its PAH content. But even that doesn’t seem to be much of an issue according to this study done in 2018 which states,
Considering that there is little evidence that these beverages contain high amounts of PAH, it has become the prevailing hypothesis that the risk might not be inherent to natural compounds contained in mate, or to compounds produced during processing, but rather due to a temperature effect… The temperature effect but not PAH exposure may pose an oesophageal cancer risk.
If it’s neither PAHs or water temperature, then what is it?
The only solid evidence so far for yerba mate increasing the risk of cancer seems to be when it’s consumed in conjunction with smoking and consuming alcohol. Other lifestyle factors such as obesity and diet may also play a role, which leads me to my next point…
Bigger Things To Worry About
Let’s admit it: we’re all afraid of getting cancer.
But there are probably several things you’re already doing (and/or not doing) daily that create a greater risk for cancer, whether it be smoking, consuming lots of alcohol, being sedentary, or eating a high processed food diet.
If you’re not attending to these things first, worrying about yerba mate giving you cancer or being unhealthy, and determining whether it’s worth drinking or not, should be the last thing on your mind.
Plus, chances are, you’re already consuming liquids that also contain levels of PAH and at very hot temperatures (coffee for instance which brews at 195-205ºF).
Why not start there if you’re so concerned?
Besides, compared to other drinks that are possibly linked to cancer, yet are still consumed daily such as soda and fruit juices, yerba mate’s risk shouldn’t be nearly as concerning, especially when it’s natural, sugar-free, and packed with micronutrients you probably don’t get in your everyday diet.
How To Stay Safe
If you still want to drink yerba mate but want to lower your risk of health problems, you can always opt for organic unsmoked brands. Unsmoked brands are usually air-dried instead which may significantly reduce the PAH content as no smoke is introduced to the leaves.
Some good brands that come to mind include:
Another thing to take into consideration is your water temperature. Despite the previous study suggesting hot liquids don’t increase the risk of cancer, I still wouldn’t take the chance. Instead, I’d recommend drinking at whatever temperature is comfortable for you. I like to stick around 140-160ºF. But if 160ºF is too hot for you, go lower.
Lastly, be cautious about drinking mate alongside smoking and alcohol consumption. This seems to be most clear in increasing cancer risk.
Final Words
Even with everything stated in this article, more research is required for a solid concrete answer to be given. Some of the studies contradict one another, so the only thing you (and I) can do is make the best decision for ourselves.
Personally, I’m not worried.
I’ve been drinking mate for over three years now and I’ve never felt better.
I think the fear around yerba mate is exaggerated, so much that people are hesitant to even drink it without having to confirm its safe first. Meanwhile, drinks like soda and alcohol which may pose a greater risk are consumed without second thought.
The fear is also rooted in something quite minuscule – PAH – especially when we’re already exposed to it regularly.
Let’s face it: most things are (and can be) shown to cause or be associated with cancer somehow – but we do these things anyway.
The most we can do is reduce our risk.
But I don’t think to avoid yerba mate – a nutritious plant with numerous healthy vitamins, minerals, antioxidants, polyphenols, xanthines, saponins, and more – is going to do a great job at that. Rather, the opposite.
P.S. Nothing in this post should be taken as absolute fact or used as medical advice. These are only my thoughts and opinions. Seeking a professional first is always recommended.
Hi, I think one way to mitiga this risk is to lower the temperature at which you drink mate.
Yes, I know, in many parts of the world this would be considered a crime in itself, but you are protecting yourself from that risk if you are able to reduce the temperature to safer ranges, say 65-70 degrees.
Thanks for your post!
Gustavo.
Hey Gustavo,
Definitely. That’s exactly where I like to keep my water temperature most of the time.
Thanks for reading!
Cheers,
Darren
This is an awesome article. I couldn’t agree more. Thank you!
Always been having this in the back of my head when i order the next months mate. Must say it bugs me there are no real study in this area. I sure would like to know if its just hot air or real issue. Been drinking 2-3 litres a day for many years. And had my share of smoked mate.
Thanks for posting this i only got unsmoked this time :).
K.
Terrere is the way
Is the water temperature issue related to the brewing temperature or the drinking temperature after brewing?
The author compares the health risk of coffee to Yerba Mate. However, I am under the understanding that Yerba Mate is smoke dried. Isin’t coffee oven roasted?
For years smoked foods have proven to be health risk. I love Yerba Mate and enjoy the health benefits but I will try the unsmoked leaves. After all, it is the plant that provides the benefits, not the smoking.
Hi Kat,
Thanks for the comment. Yes, despite not being smoked, the studies report that the roasting process of coffee may form PAHs.
And unsmoked mate can be a great option. Smoke-drying yerba is more traditional and for added flavor than for any health benefit.
Cheers,
Darren
I’ve been able to find studies comparing PAH levels in yerba mate as compared to coffee and tea, however it’s never mentioned whether the yerba mate tested is smoked or unsmoked, and there is nowhere a comparison of PAH levels in smoked vs unsmoked yerba mate. This article, like others I’ve read, says that smoking adds PAHs to the yerba mate, but then later says that unsmoked yerba mate “may” contain less PAHs. That seems to be the language always used and it seems no one can find information about the PAH levels in unsmoked yerba mate. I would love to see a study comparing specifically unsmoked yerba mate to coffee and teas, and since I love kukicha, which is roasted, I would love to know about that, too. In the meantime, I don’t know what to think. If anyone knows of any information, please post the link.
Hi,
I completely agree with you here. I have also started drinking yerba mate recently, and I really enjoyed it. But I want to know how good is the version with CBD, especially for females, because I kinda liked it xD…?
First, I want to thank you for this post. I’m glad someone addressed this misrepresentation by a minority of medical professionals. ANYTHING that is grilled, smoked, or has tasty burn marks like a good steak, burger, or even organic grilled vegetables contains PAH’s as does coffee and tea. Considering modern medicine’s tendency to ignore anecdotal evidence, even if it dates back hundreds or thousands of years, I was shocked when that articles was released by a doctor, I believe at the Mayo clinic, claiming a causal relationship between Yerba Mate consumption and cancer. I myself drink unsmoked organic green Yerba Mate and, once I learned how to properly brew it, stopped drinking coffee and hot tea. I think of all of the times I scalded my throat with a boiling hot cup of coffee and my first thought when I read that irresponsible paper on what couldn’t even be termed a study was that hot water causing the cancer, not Yerba or any other brew. There were absolutely zero controls on this “study” and NO scientific methods were employed. It is EXACTLY what the medical community would ignore if it was a supplement or natural remedy…anecdotal evidence and flawed at that. Being as the Mayo clinic is always 10 steps behind anything relating to health that doesn’t include an expensive new pharmaceutical, that institution is the last place I would look to for any real information. How long did they say people with fibromyalgia, chronic fatigue, and other diseases later proven to be real diseases, were mental disorders? The Mayo clinic is just a mouth piece for big pharma and I wondered if the release of information from a such horribly scientifically flawed “study” as fact was done to sabotage the growth of the Yerba Mate trade in the US. Honestly, I suspect motive and possibly an attempt prevent loss of market share for the coffee and tea industries. I can find no other motive for the release of such embarrassingly flawed data as fact by an institution so very full of itself.
As for my household, we make our own “iced tea”. 1.5 liters cold filtered water at 170 degrees, 3 to 4 heaping tbsp green Yerba mate, 2 tbsp organic gunpowder green tea, and 4 tbsp dried goji berries, all brewed for 7 to 9 minutes in a french press. We pour it into a pitcher with xylitol, honey, and the juice of 2 lemons, stir it well, and pour it into mason jars for later consumption. As it cools, the lemon juice clarifies the brew with a cloud of white solids settling to the bottom (No one can explain to us why that happens). The clear stuff on top of the jars tastes somewhat sweet and fruity. It is both delicious and quenching over melting ice in in my oversized Yeti cup that just tastes better as the ice melts. In the sealed mason jars, this “tea” will stay first day fresh for days if not weeks and just makes the prettiest, best tasting, clear amber colored ice tea you’ve ever tasted. The cloudy stuff that settles to the bottom, which is the lemon solids that seem to combine with the darker tannins as it clarifies the tea, is tangy and a favorite of my teen to microwave and drink hot. We don’t buy energy drinks, we make our own healthy energy drinks and it seems to have a very positive effect on our physical and mental wellbeing.
I just get so tired of “trying” to explain to my friends that this brew has in no way been proven to cause cancer and that it’s far more likely to prevent disease than cause it. Again, thank you for posting something reasonable that people can find with a google search addressing the irresponsible and unreasonable assertion that Yerba Mate causes cancer if you drink it. Scalding your throat non-stop for 20 years increases your odds of throat cancer, not beverages brimming with antioxidants and nutrients….
Please, read this: https://matexperience.com/insights/news/inym-reiterates-that-yerba-mate-is-not-cancerogenic
The most important part:
The main point of concern, according to the tabloids is the fact that yerba mate contains a carcinogen called polycyclic aromatic hydrocarbons (PAHs). They referred to a study, published in Cancer Epidemiology Biomarker and Prevention journal in 2008, that associated drinking mate with cancers of the esophagus, oropharynx, larynx, lung, kidney, and bladder, due to the substantial exposure to PAHs, including known carcinogens, such as benzo[a]pyrene.
Contrary to this, INYM noted that PAHs, whose main exponent is benzo[a]pyrene, are chemical substances that are not part of the composition of yerba mate leaves and stems. These substances, if they appear in the elaborated yerba mate, are not soluble in water, so it has been proven that their transfer from yerba mate to infusions is very low or none. The Yerba Mate Research Group of the Faculty of Exact, Chemical and Natural Sciences of the National University of Misiones (UNaM), led by Dr. Miguel Schmalko and Dr. Ana Thea, published a newer study in which the content of PAHs in the main forms of consumption of yerba mate was evaluated: mate caliente (mate), mate frío (tereré) and mate cocido. After carrying out the experiments, it was observed that none of the infusions studied exceeded the maximum level suggested by the WHO for the content of benzo[a]pyrene in drinking water (700 ng/L).
Another significant thing that contributes to an increased risk of contracting cancer, outlined by tabloids, is the thermal injury caused by very hot temperatures of water. In a referred study, drinking tea at temperatures that are higher than 65°C / 150°F is associated with an increased risk of esophageal squamous cell carcinoma.
In response to that, INYM emphasized that temperature at which the water is heated for the mate is not the same as the temperature at which the drink reaches the mouth. Traditionally, mate is prepared with water that does not exceed 85°C / 185°F . In yet another recent study, UNaM researchers revealed that the temperature of traditionally prepared mate never exceeds 58°C / 135°F when it reaches the mouth, even when they used 90°C / 195°F water for its preparation. For this experiment, they designed a special bombilla with temperature sensors that measured the temperature difference of mate between the filter of the bombilla and the opposite side that comes in contact with mouth. This experiment concluded that unlike coffee and tea, which are consumed in the cups and the infusion is put in direct contact with the mouth, the water for mate loses a lot of temperature when it comes into contact with yerba mate, and when the infusion is being sucked though the bombilla the temperature drops even more.
So it seems there is nothing really dangerous to worry about. It was all exaggerated and biased.
Hey Vladimir,
Thanks for sharing! I have read that article. It’s great news and is just further proof that we have nearly nothing to worry about. Keep on sipping!
Cheers,
Darren
I visited Paraguay, and spent a week visiting some of the poorest parts of Asuncion. I was welcomed with open hearts, open doors, and of course, terere. There were many stories of lives cut short, often by cancer, but the association I took away was with the massive, unregulated dumping of carcinogenic chemicals in the river, which had recently flooded the neighborhood (again). Any finding of negative health outcomes from Yerba Mate consumption in this population would be impossible to distinguish from the massive risk of simply living in an area without the sort of environmental enforcement we take for granted in the US or Europe. I’ll be interested in further research, but meanwhile, I’ll take my chances.
I would be more concerned by mycotoxins occurrence, produced by different molds in the field and then during the storage than by PAHs.
Where can I get the unsmoked kind? Any links?
Hey Darren, I have started having only cold mate brew. I let ileavss soak overnight and then mix with lemons and other healthy options. I would think that’s a healthy way forward. What are your thoughts?