German researchers said on Tuesday they had found traces of the potentially cancer-causing chemical acrylamide, in coffee, although not in as high concentrations as in fatty foods such as potato crisps, french fries or bread, reports Reuters.
Researchers for German ecology magazine Oeko-Test found the well known chemical in all 24 brands of ground coffee and seven brands of espresso they tested.
"It was known that there is acrylamide in coffee beans. We wanted to know how much of it gets into a cup of coffee," Oeko-Test editor Hella Hansen told Reuters.
The test found the substance was present in brewed coffee, although in much lower quantities than in ground coffee beans.
The head of the German coffee federation, Winfried Tigges, said acrylamide was not present in raw coffee beans, but was formed when they were roasted.
He said coffee producers were researching ways of producing coffee without the substance building up.
"It is an issue for us. It is not clear at the moment whether acrylamide is dangerous for people, but if it is we want to get it out of coffee," he told Reuters.
"Thank goodness, it is found in very low quantities in coffee, but all coffee producers are carrying out research into how acrylamide is formed," Tigges said.
Swedish scientists earlier this year found that acrylamide was formed in very high concentrations when carbohydrate-rich foods such as rice, potatoes and cereals were fried or baked, but it was not present when they were boiled.
International experts, meeting in Geneva in June, called for more research into the agent.
They said acrylamide could cause cancer in animals and probably could do the same in humans, but it was too early to draw firm conclusions or make recommendations to the public about specific foods.
The World Health Organization (WHO), which organised the meeting of international experts along with the United Nations Food and Agriculture Organization (FAO), repeated its long-standing nutrition advice - eat a balanced and varied diet, and limit consumption of fried and fatty foods.