Thus the subtitle of this blog posting at PLoS, referencing this article on "Cigarette smoking: an underused tool in high-performance endurance training". The point being that you can write a review article to argue anything you want, with sufficient cherry-picking and chains of links.

If you are doing actual experiments and making observations or proving theorems, then to a large extent -- larger in some sciences than in others -- you are constrained by the brute facts. But when writing secondary literature, especially in areas where data is generally fuzzier, it is easy, whether deliberately or not, to write to a bottom line, including findings you like and excluding those you don't.

Something to bear in mind when reading or writing any review article.