Development and application of a food frequency questionnaire for use in breast cancer research in Prince Edward Island

The primary purpose of this research was to develop and pilot test a population specific, semi-quantitative food frequency questionnaire (FFQ) for use in breast cancer research in Prince Edward Island (PEI). It was hypothesized that Island women recently diagnosed with breast cancer would have significantly lower intakes of n-3 fatty acids, monounsaturated fats, total dietary fibre and carotenoids than would women never diagnosed with breast cancer. The research was conducted in two phases. Phase I involved the development of the FFQ. In Phase II a pilot test of the FFQ was conducted in women with newly diagnosed breast cancer and women never diagnosed with breast cancer to: (a ) verify the performance of the questionnaire in regards to the food list length, contents and format; (b) assess dietary intakes of nutrients hypothesized to play a role in breast cancer incidence in cases and controls; (c) assess dietary adequacy; and (d) to investigate to the extent possible the association of dietary risk factors with breast cancer in recently diagnosed cases and controls in PEI.

While the FFQ food list length and format were judged to be acceptable, pilot test results indicated that 13 food items were rarely, if ever, consumed. Analysis of dietary intakes by the entire sample found that dietary intakes of iron (for ages 34–49 years), calcium, vitamin E and folate were less than recommended. Multivariate analysis indicated that intakes of carotenoids and hours of vigorous exercise were the best predictors of breast cancer status in women aged 50 years and older in this sample: daily dietary intakes of carotenoids in excess of 950 RE and 25 minutes of vigorous exercise per day were associated with a lower risk of breast cancer. (Abstract shortened by UMI.).