Should we believe what we read in professional journals?

When I pick up a professional journal, I am already convinced that what I read is based on impartial research and evidence. But should I be?
My assumption that articles are being provided by professionals with the public interest as a priority is the wrong assumption. I was unaware until just recently that pharmaceutical companies and medical device companies can be very generous in order to receive positive press about their latest drug or gadget. While, as a health care professional, I would like to believe that other health care professionals can provide unbiased research despite the gifts, I am not that trusting of human nature.
To be fair, journals are taking steps to prevent this practice of padding their publications with articles favouring the “latest and greatest.” Until it becomes routine, and every journal checks the background of their authors, I would suggest a double-check on that research your case may depend on.