As Mr. Liechtenstein pointed out, the bulk of academic research in these areas, the bulk of all research in these areas, is funded by the large pharmaceutical companies, who clearly have a vested interest in certain outcomes.
This is one major reason why the dereliction by our government of its duty to investigate these questions is so serious. We, the public, need to be able to find reliable (i.e., unbiased) information about the products being offered, recommended, or prescribed to us. Government-funded research was our best hope of getting that information, but it has been cut severely, often at the behest of lobbyists for the same industries that then go on to fund their own investigations, carefully managed to produce only appropriate results.
And the outcome for American citizens is our continuing decline among the industrialized nations on almost all measures of health, longevity, and wellness.