“Epidemiological evidence for very hot beverages and human cancer has strengthened over time”, the authors wrote.
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“Quitting smoking and reducing alcohol consumption are much more significant for reducing cancer risk than the temperature of what you’re drinking”, said Dr. Otis Brawley, chief medical officer of the American Cancer Society.
“The large number of tests now available has led to a re-evaluation of the carcinogenicity of drinking coffee”, the IARC said after reviewing “more than a thousand studies in humans and animals”.
In 1991, coffee was classified as a possible carcinogen, which is what sparked the detailed review in the first place.
When the World Health Organization experts looked back at the studies that did finger coffee as a cancer-causer, they found some troubling weaknesses.
Experts convened by WHO’s International Agency for Research on Cancer, or IARC, concluded there was inadequate evidence to suggest that coffee might cause cancer, according to a letter published in the Lancet Oncology.
The heat emanating from a coffee cup, or any hot drink, remains a risk and previous studies have suggested an optimal drinking temperature of 57.8 degrees Celsius – 136 degrees Fahrenheit – or below. They found the hotter a participant drank their tea, and how long they let the tea brew before drinking it, the greater their risk of cancer.
In its evaluation of very hot drinks, IARC said animal studies suggest carcinogenic effects probably occur with drinking temperatures of 149 degrees or above.
The agency says drinking beverages at temperatures above 65 degrees Celsius could cause people to develop esophageal, which is the eighth most common form of cancer worldwide. “Mate is not only prepared very hot, but drunk through a metal straw that delivers it directly into the throat”.
“As a heavy coffee drinker, I have always enjoyed my coffee guilt-free”, he said.
“(This) does not show that coffee is certainly safe. but there is less reason for concern today than there was before”, Dana Loomis, the deputy head of IARC’s Monograph classification department told a news conference. “This is great news for coffee drinkers, and confirms evidence from an avalanche of studies by highly respected and independent scientists”, said National Coffee Association President Bill Murray. Although it makes up roughly 1 percent of all cancer diagnoses in the US, it is much more common in Iran, China, India, and South America.
The findings come after a string of similar reports that link food and drink to cancer. A Western diet is typically considered to be low in fiber and high in refined sugars, saturated fats and animal protein.
Researchers reviewed more than 500 studies on more than 20 different types of cancers.
After a review of more than 1,000 biomonitoring studies, the group found that up to 420 chemicals known or likely to cause cancer have been detected in blood, urine, hair and other human samples.
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Drinking very hot beverages is now classified as probably carcinogenic in IARC’s group 2A category, alongside red meat and nitrogen mustard.
