If you change enough variables at once, it's pretty hard to get clear knowledge of harm. We're not out there running controlled experiments on every new substan

If you change enough variables at once, it's pretty hard to get clear knowledge of harm. We're not out there running controlled experiments on every new substance, or collecting robust data. The rapid rise of unexplained autoimmune disease over the past few decades (one of quite a few negative health trends) indicates that our knowledge of what is harmful is incomplete.