Not long ago, it was "conventional wisdom" to blame sweets and starchy foods for fattening people. Then came the low-fat era and "everybody" KNEW that eating fat made people fat....
I know -- i was there.
I read Eat To Win and Beyond Diet (and similar things). I bought the idiotic hypotheses presented there. I know from personal experience that they don't pan out in real life.
Truly traditional "wisdom" is a little bit different. It's based on trial-and-error behavior spanning much more time.
If one had never heard about the "scientific" hypotheses of diet during the last half of the twentieth century one would be much better off ... and WISER.
We tend to trust those who are formally educated in the western world. We have a hard time believing that what they propound is not scientifically sound ... but such can be the case. Those holy scientists CAN be personally corrupt -- by colleagues who can make or break their careers insofar as they conform to or defy their patrons' ideological positions, and by sources of financing for their pet projects.
This is why anyone who defies the status quo deserves a little benefit-of-the-doubt, IF their hypotheses stand up to a reasonable degree of inspection. If traditional experience AND philosophy support an idea, we should look at it closely before consigning it to the dungheap of sophistical idiocy.
Ignorance of modern science IS more rational than familiarity with pseudo-science. The devil can quote scripture to his own advantage, and people with an axe to grind can find studies at PubMed to back themselves up, too.