1. From the Nutritional Epidemiology Program (ML, GR, and PFJ) and the Laboratory for Nutrition and Vision Research (AT), Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA; the Departments of Epidemiology (SEH and WCW) and Nutrition (WCW), Harvard School of Public Health, Boston, MA; and the Channing Laboratory, Department of Medicine (SEH and WCW) and the Cent