I focused on the first one I clicked. It took a lot of digging (like searching google and clicking the first link), but I found some counter studies: http://thepaleodiet.com/published-research

Either way, to each their own. My research and experience has led me in a certain direction, and the results in my personal health and those around me have been fantastic. In all actuality only time will tell. Obviously the state of current knowledge in the area is widely inconclusive. Best of luck to you.