The Norwegian Women and Cancer Study (NOWAC), a prospective study on diet, lifestyle and cancer, became officially associated with EPIC in 2000. The study extended the scope of EPIC by providing valuable information on the nutritional habits and disease risk of a northern European population. NOWAC was set up to study the effect of different lifestyle factors on cancer incidence and mortality and was initiated among Norwegian women. The cohort consists of different sub-studies which have common core questions. Questionnaires were completed by 103,000 women between 1991 and 1997 and increased to 172,000 women by the end of 2006. The part of the cohort included in EPIC consists of 37,226 women, aged 35 to 49 years at recruitment into the sub-study "Women, Lifestyle and Health" in 1991/1992. They completed a second questionnaire in 1998 (the Norwegian EPIC-questionnaire), and were recontacted in 2004-05.

All cancer cases and deaths are available from national registries. By the end of 2007, 741 women had died and 1953 women had got a new cancer diagnosis.