Caramel Color

4-MEI is a by-product that forms in caramel color made with ammonia. It has been linked to lung tumors in mouse studies and classified as possibly carcinogenic to humans.

Caramel color is a brown coloring made by carefully heating sugars such as dextrose or molasses. FDA lists it as a color additive exempt from certification. Some types, called Class III and Class IV, contain 4-MEI, and FDA notes a 2-year mouse study found more lung tumors at doses far above human exposure. Studies in cats are lacking. If your cat has a medical condition, ask your veterinarian about its diet.

Source: fda.gov

Caramel color is added to make food look browner, closer to roasted meat or gravy. The color matters to the person buying the food more than to the cat, which picks food mainly by smell. It adds no meaningful nutrition. Makers use it in small amounts in both kibble and treats.

It sits in between. FDA groups caramel with colors exempt from certification, the same group as vegetable juice, rather than with FD&C dyes. Some caramel is made with ammonia or sulfite compounds, though, and AAFCO's definition of natural excludes ingredients made by a chemically synthetic process. Pettings lists caramel color as an artificial color because the label does not say which type was used.

Source: govinfo.gov

It is made from sugar, but it is not used as a sweetener. FDA defines caramel as the dark brown material that results from controlled heating of food-grade carbohydrates such as dextrose or molasses. That heating changes the sugars into color compounds. The amount added to cat food is small, so it contributes little to the food's carbohydrate content.

Source: govinfo.gov

Pettings gives caramel color 0 out of 5 and lists it as an artificial color. It appears on 7 of the 149 dry cat foods we list. It scores at the bottom because it changes only how the food looks, and some types carry 4-MEI. Each food's page shows how it scores overall.