1. Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU)Nuffield Department of Population Health, University of Oxford Oxford United Kingdom
2. Medical Research Council Population Health Research Unit (MRC PHRU), Nuffield Department of Population HealthUniversity of Oxford Oxford United Kingdom
3. Chinese Academy of Medical Sciences Beijing China
4. School of Public HealthPeking University Beijing China
5. National Center for Food Safety Risk Assessment Beijing China
6. National Institute for Health Research Oxford Biomedical Research CentreOxford University Hospital Old Road, Oxford United Kingdom