Skeletons from before 1900 show less dental decay compared to modern populations, indicating diet as a primary factor.

“if we look at skeletons from dead people obviously well you can look at skeletons and live people skeletons and dead people uh from dead people that um died prior to 1900 how are their teeth 1900 they still have they would have Decay but if you looked at about 10 thousand years ago um very little”