I've written about the Paleo diet before. As far as I know, there are no scientific studies in peer reviewed journals that support the Paleo diet and I don't trust anything that isn't backed by impartial schools and is missing from peer reviewed journals. There are, however, tons of studies (both in the lab and clinical with people) and in peer reviewed journals that show eating meat, dairy and other animal products cause cancer and other sickness. It's the proteins in these animal products that turn cancer on and off, and they exist regardless of where the animal came from or what it was fed or how it was treated. The evidence is indisputable, a whole foods, plant-based diet is the only diet that is healthy, will prevent and reverse disease and is also the only diet that is truly sustainable for our world. A biological archaeologist for NPR wrote an article about how the Paleo diet isn't reflective of what caveman ate (and how it's not great for today's work either) see: Paleo Diet: Not the Way to a Healthy Future .