I do think this is key. My Dad drinks no sugary drinks of any kind, including not just soda but fruit juice, etc. And I've basically stuck to that. Not big on sweets either. That stuff is killing us, seriously.
For example, most colas contain phosphoric acid. Phosphoric acid is the same thing your dentist will swab on your tooth during a basic reconstructive filling procedure, because it softens the enamel a wee bit, ensuring a better bond to the filling.