1. Biomedical Research Laboratories, Kureha Corporation, 3-26-2 Hyakunin-cho, Shinjyuku-ku, Tokyo 169-8503, Japan; Department of Public Health, School of Medicine, Kurume University, Kurume, Fukuoka 830-0011, Japan; and Department of Nutrition, Junior College of Tokyo University of Agriculture, Tokyo 156-0054, Japan