I agree it's always best to question and appeals to authority are atill fallacies. Having said that, this site (examine.com) is a fantastic site that bases their recommendations around published and peer reviewed studies. In the absence of such evidence they'll make calculated guesses on some things but specifically state that there isn't much evidence. The site is run by MDs, PhDs, biochemists, molecular biologists, nutritionists, etc. Here's the link to the info on the main authors and again it's a site I go to for unbiased information
What is Examine.com? | Examine.com