This piece has some enormous lessons.
1. "Science" can be go badly wrong when a small group of individuals, who've taken control of journals and funding in a field, decided to protect their positions at the expense of truth.
2. This is especially true if controlled experiments are few to none.
3. This is even more especially true if the federal government is involved.
Do 1 through 3 remind you of anything?
4. Nobody--absolutely nobody--should be allowed to tell the public what to do unless they've had a thorough grounding in the difficulties of establishing causality.
5. Unexpected effects are almost everywhere.
Related: salt, too, was terribly misjudged.