The assumption that industry-funded studies are intrinsically inferior to a non-industry-funded study is an article of faith to many people; in the most extreme cases, the mere fact that a study was funded by industry is sufficient evidence to consider it total garbage. This is challenged by an interesting paper in the International Journal of Obesity, where it is shown that industry studies consistently have a higher quality of reporting than non-industry studies in the field of obesity studies.
It's worth carefully reading the sketch of a definition of "quality of reporting" they give in the second paragraph of the introduction to see exactly what they are saying. While still possible that these studies are reporting faked data in high definition, the definition of "quality" does encompass some things that make that more difficult. Not impossible, but difficult.
This paper isn't sufficient to prove that industry studies are always better, or any other absolutist claim on the other end of the spectrum. But I do think this is sufficient to say that the presumption of non-industry superiority is quasi-religious, not based in fact. Studies must be judged on their own merits, and personal attacks remain a logical fallacy, even, perhaps especially, when dealing with science.