Blondie, spot on. They have no studies. The writers of these articles have to be working on them for months before they appear in the WT, etc. Assuming they have any training at all, they know that definitive statements require support by empirical data in articles that have any credibility. They also know that there are studies on just about everything imaginable and have time to research the topic completely and cite sources for their comments.
It is likely that any sources/studies they quote would be ripped to shreds by its detractors and by some rank in file who cared enough to actually do some research, which takes a few minutes now on the 'Net. I would expect to see more articles and statements supported by 'some studies' in the future. They lack any academic credibility; they are written to control the under-educated and the brain dead.