WHO rating Coffee not carcinogenic, very hot drinks, however

IARC rates coffee as non-carcinogenic, but warns of very hot drinks
For a long time, coffee was considered to be more harmful to health and there were speculations about possible connections with cancer. In a recent study, the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) now comes to the clear conclusion that coffee has no carcinogenic effect. On the contrary, coffee can evidently even protect against two cancers. However, according to the scientists, very hot drinks are generally associated with an increased risk of esophageal cancer. The researchers published their results in the journal "The Lancet Oncology".

In their current study, the IARC scientists examined possible correlations between the risk of cancer and the consumption of coffee, mate tea and other very hot drinks. They conclude that "there is no conclusive evidence of a carcinogenic effect of coffee". With mate tea, as with other hot drinks, the consumption temperature played a significant role in cancer risk. The study findings "suggest that consuming very hot drinks is a likely cause of esophageal cancer, and that the temperature, rather than the drinks themselves, seems to be responsible for this," Dr. Christopher Wild, director of the IARC.

For many people, coffee is a practically indispensable part of their everyday lives. You can now continue to enjoy calmed, an increased risk of cancer does not arise from the coffee consumption. (Image: Rawpixel.com/fotolia.com)

More than 1,000 cancer risk studies evaluated by coffee consumption
The international working group of 23 IARC scientists, on behalf of the WHO, evaluated the carcinogenicity of coffee, mate tea and very hot drinks. For this purpose, the researchers analyzed the results of numerous older studies worldwide. According to the results, coffee consumption is no longer classified as "potentially carcinogenic to humans" (IARC rating of 1991). "After thoroughly reviewing more than 1,000 studies in humans and animals, the working group has determined that there is insufficient evidence of carcinogenicity in coffee consumption," the IARC Communication said.

Reduced risk of two cancers
According to the researchers, many epidemiological studies have shown that coffee does not increase the risk of breast cancer and cancer of the pancreas or prostate. In addition, coffee consumption is associated with a reduced risk of cancer of the liver and uterus, reports the IARC. For more than 20 other cancers, the researchers were not scientifically reliable rating possible, so that it remains unclear to what extent coffee consumption has an influence on the disease risk.

Temperature crucial for cancer risk
For mate tea, the researchers found in their analysis that this had no carcinogenic effect in animal studies and epidemiological studies, as long as he was drunk cold. The consumption of mate tea is widespread, especially in South America, but in Europe and North America, the tea from the dried leaves of Ilex paraguariensis recently enjoyed a strong popularity. Mate is traditionally drunk very hot (at around 70 ° C), but can also be consumed hot or cold, explain the IARC researchers. For the very hot tea applies, as well as for other drinks that are drunk with correspondingly high temperatures, that this "probably carcinogenic", so the result of the working group.

Also very hot water with carcinogenic effects?
For the very hot drinks, the epidemiological studies evaluated generally found a positive association with cancers of the esophagus. "Studies in places like China, the Islamic Republic of Iran, Turkey, and South America, where tea or mate is traditionally consumed very hot (at around 70 ° C), have found that the risk of esophageal cancer increases with the temperature of the drinks," This is the message from the IARC. In experiments with animals even for very hot water would have been evidence of a carcinogenic effect.

Risk of esophageal cancer due to very hot drinks
Although smoking and alcohol remain the major causes of esophageal cancer, especially in many high-income countries (...), the majority of esophageal cancer cases occur in parts of Asia, South America and East Africa where regular consumption of very hot drinks is commonplace. " , said the IARC director Wild.

The reason for the high incidence of this cancer was previously unclear and the consumption of very hot drinks could possibly play a role here. According to the IARC, esophageal cancer is the eighth most common cancer in the world and was one of the deadliest forms of cancer in 2012, with approximately 400,000 deaths. The proportion of esophageal cancer cases, which can be associated with the consumption of very hot drinks, remains according to the researchers unclear, but could be considerable. (Fp)