The two I'll point out here are Fluoridation and Pasteurization.

The two I'll point out here are Fluoridation and Pasteurization. Proof that we're so comfortable living in our clean cities drinking clean water and eating clean food that we think we don't need this stuff to keep us alive. Hence the raw milk advocates, anti-vaccers, and fluoridation conspiracy theorists. We must preserve our precious bodily fluids.
http://www.slate.com/articles/health_and_science/science_of_longevity/2013/09/life_saving_inventions_people_and_ideas_cotton_shoes_fluoride_the_clean.html