Everyone should read this book I found on the Apple Store:
Medicinal Marijuana & Other Cannabinoids
By NetCE and Mark Rose
This is an actual observation over the past twenty years by a collective of doctors that have done the tests that everyone has wanted to know the answers to for years.
My one point of information would be that all mammals have an endocannabinoid system built into their bodies with receptors that bind to this plant specifically. If the human body has evolved to coexist with anything, it is this Plant.