The good news is that coffee is probably not a carcinogen; the bad news is that you'll still want to be on the lookout if you like to drink it really, really hot. In light of new research, the World Health Organization (WHO) has dropped coffee's status as a possible carcinogen; however, they also still note that very hot drinks might be connected with cancer — which means that drinking coffee can still be a cancer risk if it's heated up too much. Basically, this might be the first time anyone has ever found anything good about lukewarm coffee.
Coffee has been a suspected carcinogen since 1991, but a review published today, which was the result of research done by 23 scientists from 10 countries, contradicts those findings — as do previous studies suggesting coffee may actually protect you against some cancers. The WHO research also looked at mate, a form of herbal tea common to South America where esophageal cancer is particularly common, and at types of tea commonly consumed at high temperatures in East Asian countries. In the end, the researchers concluded that even though these substances were linked to cancer, it wasn't because of the drinks themselves, but rather possibly due to their temperature.
The findings, however, aren't definitive. “There is limited evidence in human studies, and limited evidence in animal studies, for the carcinogenicity of very hot drinks,” said Dr. Dana Loomis from the International Agency for Research on Cancer (IARC), who led the study. That means that nothing has been proven yet. But based on this new and substantial research, the IARC has categorized hot beverages as “probably carcinogenic to humans.”
So what does this mean for those of us who like coffee and tea? Obviously we'd all like to avoid cancer, but how hot qualifies as risky here? Do we really all have to start drinking tepid coffee?
Fortunately, the answer to that last one is probably no. The researchers say that 65 degrees Celsius, or about 149 degrees Fahrenheit is probably too hot... which honestly shouldn't be too disappointing, given that such temperatures are also enough to burn your tongue and therefore not how most of us like our drinks. The coffee you brew at home, for example, is A-OK: Home-brewed coffee is typically about 140 degrees when first poured, below the danger threshold the WHO researchers have established.
Of course, now that it's summer we're all probably drinking iced coffee anyway. So we just have to remember this once winter rolls back around.