There is no conclusive evidence that drinking coffee causes cancer, said the World Health Organization's cancer agency on Wednesday, June 14, in a reversal of its previous warning. However, it also said all "very hot" drinks are probably carcinogenic.
The WHO's International Agency for Research on Cancer (IARC) had previously rated coffee as "possibly carcinogenic" but has changed its decision. The organization now reports its latest review found "no conclusive evidence for a carcinogenic effect" of coffee drinking and pointed to some studies showing coffee may actually reduce the risk of developing certain types of cancer.
"(This) does not show that coffee is certainly safe ... but there is less reason for concern today than there was before," said Dana Loomis, the deputy head of the IARC's Monograph classification department, at a news conference.
At the same time, however, the IARC presented other scientific evidence that indicates drinking anything very hot--around 65 degrees Celsius [149 degrees Farenheit] and above, including water, coffee, tea and other beverages--probably does cause cancer of the esophagus. Esophageal cancer is the eighth most common cause of cancer worldwide, according to a news report in Reuters, and one of the main causes of cancer death, with around 400,000 deaths recorded in 2012.
In its evaluation of very hot drinks, the IARC said animal studies suggest carcinogenic effects probably occur with drinking temperatures of 65 Celsius or above. Some experiments with rats and mice found "very hot" liquids, including water, could promote the development of tumors, it said.
Last year, the WHO concluded that processed meat can cause cancer, after reviewing more than 1,000 scientific studies in humans and animals. There was inadequate evidence for coffee to be classified as either carcinogenic or not carcinogenic. "These results suggest that drinking very hot beverages is one probable cause of esophageal cancer and that it is the temperature, rather than the drinks themselves, that appears to be responsible," said IARC director Christopher Wild.