1. From the Departments of Nutrition (XG, TTF, FBH, and AA) and Epidemiology (GL, FBH, and AA), Harvard School of Public Health, Cambridge, MA; the Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School (FBH and AA), Boston, MA; the Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC (HC); the Department o