The study by John Hopkins that links soda to cancer is bunk lol. It wasn't even a study. All they did was calculate the exposure level of the coloring (4-MEI) over time and concluded that the exposure level over time would exceed the level considered safe. They said that routine drinking of soft drinks would result in the risk of 1 cancer incidence among 1 million people (seriously??!)... and that is considered an acceptable level by US regulatory agencies. Even researchers are critical of this "study". A professor of food chemistry and environmental toxicology at the Univ. of California says "There is no evidence that 4-MEI (the caramel food coloring in sodas) causes cancer in humans".
But anyway... enjoy your iced coffee