1. From the Departments of Food Technology (KK, HT, and AK), Public Health (KS), and Medical Genetics (MP),University of Helsinki, Helsinki, Finland; the Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland (KK, AK, and MP); and the Twin Research and Genetic Epidemiology Unit, St Thomas' Hospital, Kings College London, London, United Kingdom (TDS and LFC)