I work in a school of Public Health. One thing worth keeping in mind about epidemiologists is that they have the souls of accountants. Anal retentive accountants. These people sit around all day thinking about their data, and what it means, and how it might be biased.
There are standards, particularly if one wants to publish in good journals. And, seriously, drug companies are not doing (or funding) all the studies on risk factors for cardiovascular disease. Plenty of academics are doing this type of research as well.
If you're forming an opinion on a question such as this, I strongly recommend that you go to pubmed at
http://www.ncbi.nlm.nih.gov/entrezThis site is run by the National Library of Medicine, and has virtually all the major (and zillions of minor) journals in the life sciences. It's free to use, and in addition to reading the abstracts, you can frequently find free full-text articles as well. If I were you, I'd pick up a couple of recent review articles, then you can form an opinion that is informed by the current best understanding of science.
Yes, drug reps are prostitutes. That doesn't mean they're always wrong or deceitful.