The reference you site is a book and not a medical journal. Is Zimmer and Morgan's work on this subject published in any medical journal?
No, of course not. They cite studies found in many types of journal, some medical, many from research funded by the US Government. I count 65 pages of cites to references.
If you don't like their conclusions, then find the book and refute it. Buckley, Jr. did a column couple years back using the data found in it. Perhaps you can find it in his archives on the web.