[1] Harvard Univ, Sch Publ Hlth, Dept Nutr, Boston, MA 02115 USA
[2] Harvard Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA 02115 USA
[3] Univ E Anglia, Sch Med, Norwich NR4 7TJ, Norfolk, England
[4] Brigham & Womens Hosp, Dept Med, Channing Lab, Boston, MA USA
[5] Brigham & Womens Hosp, Div Prevent Med, Boston, MA USA
[6] Merck Res Labs, West Point, PA USA