[lonecom]

> major shift in the knowledge about risks of things like sugar, cigarettes, alcohol...

In each of these case, the medical and scientific community didn't have a vested interests in these entities. I mean, the medical community didn't come up with smoking or alcohol consumption...

Now imagine some entity or procedure that the medical/scientific community came up with and the big business found way to make huge money off of, such that there is a natural alignment of incentives for the scientific community and big business to keep this thing propped up. Such a thing, even if doing great harm, is sure to go on for a vastly longer period of time, if not perpetually....