decades of consuming crap that is filled to the brim with various chemicals and/or medications for animal products. the air, water, and soil are all infused with chemicals/plastics/heavy metals now. vegetables/fruit are engineered to to produce their own pesticides. the medical industry has spent the last 4-5 decades throwing various synthetic drugs are people.  there is no one thing. this is not a simple problem. this is just the start.
United States