If you search the Internet for information on alcoholism, amino acids, autism, or many other things that start with A, you'll find various scholarly, personal, and commercial offerings to browse. Inevitably, you will find conflicting data. Different authorities define autism by different criteria. There are at least 20 and maybe as many as 29 different amino acids in the food we eat. Alcoholics Anonymous is "the most effective" treatment program for alcoholism, or maybe it just fosters more dependence on something other than alcohol.
The experts do not agree. If I were a little more paranoid, I'd suspect the pharmaceutical, healthcare and insurance, and mental health industries have a self-perpetuation agenda, whereby they disinform the public and pollute their own research in order to perpetuate their own product cycles and authority.
I'm not that paranoid. I think The Expert Factor is combined bad reporting, amateur misinformation, and good science leading to faulty conclusions. Of course, there's the hype factor, but it's not too hard to spot an "expert" with a product to sell.

Try getting some good information on chromium picolante, the diet aid, some time. Every company who sells a product based on it gives a lot of "expert testimonial" to further their cause, whereas the FTC point out that the companies involved are being investigated for fraud, and don't point to any research with any sort of backup to their claims of it causing various cancers and the like.

I can't find any official word from the FDA, but I'd really like to (even artificially) boost my metabolism and get my body into some sort of shape without looking like Ally McBeal.