Read the excellent book EAT TO LIVE recently released and chock full of data, graphs, etc. Dr. Joel Furhman...the book is not strictly veg, but it's very well researched and all about diet, emphasis on vegetarian. There are all the scholarly references and footnotes in that book. Also check out Dr. Dean Ornish's studies and The China Study (which Fuhrman references often in his book). Good luck!