Dietary change among breast and colorectal cancer survivors and cancer-free women in the Norwegian Women and Cancer cohort study

To study diet before and after diagnosis of breast and colorectal cancers compared with diet in cancer-free women in the Norwegian Women and Cancer study. This paper reports dietary changes from a data collection in 1996-1999 to another in 2002-2005. A total of 43,847 cancer-free women aged 41-70 years answered the baseline questionnaire on diet and lifestyle, 130 women developed colorectal cancer and 563 breast cancer. Dietary change in the three groups was compared, for breast cancer a comparison was made according to stage and time since diagnosis. Breast cancer survivors increased fruit and vegetable consumption with 81 g compared to 42 g in colorectal cancer survivors and 50 g in cancer-free women (p difference in change < 0.001). Milk consumption decreased among cancer-free women, but not among colorectal cancer survivors (p = 0.007). Significantly more cancer survivors quit smoking (p < 0.001). There were no differences in change of alcohol consumption or BMI. In breast cancer survivors, differences increased with time since diagnosis, and stage II survivors made larger changes than stage I survivors. Cancer survivors showed little change toward cancer-preventive guidelines, although more advanced stage and being more than 2.4 years post diagnosis was associated with greater change in diet and smoking behaviors.