A lot of industries — and businesses not pejoratively called industries like farmer’s and rancher’s cooperatives — have used the techniques of “big tobacco” to sell their products, and overcome regulation. When businesses of all sorts band together, they produce their own science and research, and use those claims to back up their marketing. Often government and academia is deeply involved in supporting these industries, and you have be very skeptical of claims put out and weight the pros and cons of any scientific study. Skepticism matters!