If the problem lays mostly in the people trying to sell multivitamins, refined sugar, milk, etc and journalists pushing bad information to sell more papers, that sounds much more like a failure of capitalism to regulate itself than a failure of science to discover facts.
Yes, preliminary studies were used as justification, but it's not the scientist's fault that media and private interests ran with unconfirmed data as long as the scientists made clear that the studies weren't definitive. The main failure on science's part is a failure to be more vigilant in refuting bad information.