Scientists are paid by huge corporations to make findings that are favorable to them. One instance of this is the soy controversy, where there is this myth going around that consuming it raises your estrogen levels. This "finding" was done by scientists hired by the commercial meat and dairy industry to demonize a plant that would naturally compete with those industries as a dairy substitute. The reality is that plants are asexual and thus create phytoestrogen for themselves, of which they use to reproduce with, which is completely different from mammalian estrogen (ACTUAL estrogen) which comes from cow milk that we consume regularly.

Also, pharmaceutical companies lose lots of potential profits from healthy people so the incentive to slander competition is there, for the purposes of justifying quarterly profit margins.