The Grocery Manufacturers Association says the carcinogen acrylamide is found in 40 percent of the calories consumed in the average U.S. diet, including roasted coffee beans, french fries, potato chips, breakfast cereals and toast. Now, a California judge has ruled every cup of coffee sold be labeled with a cancer warning. Roasted coffee beans contain a acrylamide, but previous medical studies say it's unclear whether the levels are high enough to pose a health risk to humans.