Photo by orva studio on Unsplash I’m delighted to feature this guest post by Laura J. Arul, MD, of L.J.A. Medical Communications.  Twenty years ago, researchers Michel Poulain and Giovanni Mario Pes used a tool called the Extreme Longevity Index, or the number of centenarians (persons aged 100 and older) per 10,000 newborns, to identify … Continue reading What Are the Blue Zones?