When did you start to switch from formula/breast milk to whole milk?

I know no one is perfect and every child is different. I have a 7 1/2 month old who spits up and I am constantly being told that if I were to switch him to whole milk, that he wouldn’t spit up as often. Just wondering when to make that switch. I feel like he is still too young, but I’ll try anything if it will help his tummy.