If you are a fan of Pepsi-Cola or other caramel-colored soft drinks, here’s something that might change your mind.

The food coloring in it, 4-methylimidazole, or 4-MEI for short, might cause lung cancer.

“There have been some studies in female and male mice which have associated this chemical, this 4-MEI, with an increased risk of lung cancer,” says Dr. John P. Higgins, an Associate Professor of Medicine at The University of Texas Health Science Center at Houston.

4-MEI is believed to cause cancer in humans as well. Caramel color is the most used food coloring in the world.

“I think if you look at labels again and you see food or a beverage that actually does use the word ‘caramel color’ or ‘caramel coloring,’ it is possible that product does contain some of the 4-MeI,” Dr. Higgins tells KTRH News.

A couple years ago California passed a proposition requiring manufacturers have a cancer warning on the packaging of any product that contains more than 29 micrograms of (4-MeI).

Consumer Reports tested soft drinks containing (4-MeI) purchased in California and New York State. New York-manufactured product was found to have relatively more amounts of the coloring compound than California products. However Diet Pepsi and Pepsi One sold in California were found to have higher than legal limits. Malta Goya had the highest levels of all.

“If you really want to be safe about this it might be best to avoid food and or beverages that actually contain this caramel coloring until we know more about the link between the substance and possible cancer,” says Dr. Higgins.

In all of the tests, Coca Cola was found to have some of the lowest level of (4-MeI), in regular, diet and Coke zero. Dr. Pepper, iced tea, and A&W Root Beer were all consistently below the 29mcg threshold.

Pepsi, Diet Pepsi, Pepsi One and Malta Goya consistently tested above approved levels.