1. ¹Epidemiology and Surveillance Research Department, American Cancer Society, 1599 Clifton Road, NE, Atlanta, GA, USA
2. ²Departments of Epidemiology and Nutrition, Harvard School of Public Health, Boston, MA, USA
3. ³Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA USA

Correspondence: ML McCullough, E-mail: marji.mccullough@cancer.org

Abstract

Dietary effects are presumed to underlie many of the large international differences in incidence seen for most cancers. Apart from alcohol and a few micronutrients, however, the role of specific nutritional factors remains ill-defined. The evidence for a role of energy balance, physical inactivity, and obesity has strengthened, while for dietary fat it has weakened. Phytochemicals such as folate, lycopene and flavonoids are still the subject of active research. As the mechanisms underlying human carcinogenesis are better understood, dietary research will focus increasingly on intermediate markers such as the insulin-like growth factors and potentially carcinogenic metabolites.