That just means that food commonly eaten in the US doesn't allow you to avoid cavities. It doesn't mean there are no such diets, nor that there aren't diets typ

That just means that food commonly eaten in the US doesn't allow you to avoid cavities. It doesn't mean there are no such diets, nor that there aren't diets typical for some regions that avoid cavities. Caries is also an infectious disease. It's extremely common but not everyone is infected. There are tribes that simply don't have it.