Americans drink 80 billion cans of soda a year even more than beer, milk and bottled water.
But now the Center for Science in the Public Interest is targeting a soda ingredient it says may cause cancer, the caramel coloring. The chemicals in the caramel cause cancer in mice.
But some independent experts say consumers should relax because something happens at a very high dose in animals doesn't mean it will translate in low doses in people.
The FDA says that it and the World Health Organization is already studying the chemical and its potential effect on humans.