Science and scientific discoveries are indeed wondrous things. That Newton's third law - about every action having equal and opposite reaction - goes beyond physics and applies to human nature is well known. After all, our propensity to often do exactly what we are exhorted not to do is a manifestation of that; the whole concept of forbidden pleasures is predicated on it. That could explain why scientific discoveries, conducted as they are by essentially contratrian human beings, end up proving opposite things with unfailing regularity.
The mission of science to prove that one person's superfood is another person's poison, is clear from the recent announcement about chocalate actually helping people to slim down.
There will definitely be a counter-discovery in the near future of the role of chocolate in exacerbating the deleterious aspects of excessive caffeine intake.
Some of these studies and discoveries are, of course, funded by interested groups, but these are easily determined.
Most of them, however, convey the impression that bored or underemployed scientists begin with a new idea or myth-busting notion and then go about proving their hunches to be true. Considering human beings are as gullible as they are contrarian, every discovery gets its complement of believers - till the next one supplants it. We now need laws of human nature to put this in perspective !