One of the things you notice in prehistoric skeletons is the presence of very poor dental health - there are variations and exceptions, depending on time and place, but very often by the time you hit forty, your teeth were likely to be toast.

"The human race was doing just fine" as a population, but individual life expectancy was remarkably short - I believe it was something like 49 years or so in mid-nineteenth century in the USA. Back in the Pleistocene, I believe you kicked off in your 30s.

You asked a question about finding a filter that would handle fluoride, and I believe you got an answer. Why you would want such an item is your business and none of my own..