1. From the Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging (JJF-C, JTD, ES, LMT, and PFJ), the Friedman School of Nutrition Science and Policy (JJF-C, JTD, LMT, and PFJ), and the School of Medicine (JTD and ES), Tufts University, Boston, MA; the General Clinical Research Center, Beth Israel Deaconess Medical Center, Boston, MA (JJF-C); Tufts–New England Medical Cent