Coffee was listed as a possible carcinogen in 1991 but the World Health Organization's (WHO) cancer agency on Wednesday said that there is no conclusive evidence that show drinking coffee can cause cancer.
The International Agency for Research on Cancer (IARC) earlier listed coffee as possibly carcinogenic in its 2B category along with other substances such as lead and chloroform.
The IARS, however, made a reversal to its previous warning based on results of a new review which found no conclusive evidence for the carcinogenic effect of drinking coffee.
A working group of scientists convened by the IARC reviewed more than 1,000 studies in humans and animals.
In many of these studies, the researchers did not find evidence that drinking coffee can cause cancers of the female breast, pancreas and prostate. The evidence was likewise inconclusive for more than 20 other types of cancer.
In contrast to WHO's earlier warning, some studies even show that coffee may slash risks for 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, from the Monograph classification department of the IARC.
Coffee, however, is still not in the clear if it is drunk at very high temperature.
The working group has found positive link between cancer and drinking very hot beverages. Scientific evidence suggests that drinking anything such as coffee, tea, and other beverages at around 65 degrees Celsius or above may cause cancer of the esophagus.
In China, Iran, Turkey and South America, where a traditional tea called maté is drunk at about 70 degrees Celsius, there were evidences that show the risk for esophageal cancer increases along with the increase in temperature the beverage is drank.
Experiments involving rats and mice also show that very hot liquids may promote the development of tumors.
IARC director, Christopher Wild said that these show that drinking very hot beverages can likely cause esophageal cancer. The drinks themselves, however, may not be responsible for the association but the temperature.
"The Working Group found no conclusive evidence for a carcinogenic effect of drinking coffee," the IARC said in a statement. "However, the experts did find that drinking very hot beverages probably causes cancer of the oesophagus in humans."
One reason hot scalding drinks may cause cancer is that they can injure the cells that line the throat, which can set off the stage for cancer.
