Colorectal cancer (CRC) is the third most commonly diagnosed cancer and its age-standardized incidence rate in the province of Newfoundland and Labrador (NL) is the highest in Canada. The relationships between major dietary patterns and CRC in other populations largely remain consistent across studies, but due to limited external validity, there is a great need to determine the major dietary patterns and their relationship to CRC in the NL population.
To elucidate the relationship between dietary habits and the health profile of the general NL population from 1999-2003, and to support information translation from the etiologic perspective into public health guidance.
A total of 506 CRC patients (306 men and 200 women, aged 20-74 years) and 673 controls (400 men and 273 women, aged 20-74 years) entered into this case-control study. Dietary habits were assessed by a 169-item food frequency questionnaire (FFQ). Two logistic regression models were fitted to investigate the associations between dietary patterns and the CRC risk.
Three major dietary patterns were derived using common factor analysis, namely the Meat pattern, the Healthy pattern and the High-sugar pattern, which explained a total of 74% of the variance in food intake. After adjusting for potential confounding factors, the Meat and High-sugar patterns were significantly associated with an increased risk of CRC, while a significantly reduced risk of CRC was observed with the Healthy pattern. After stratification by cancer of the rectum, the proximal colon and the distal colon, similar relationships were found.
Similar to in other populations, particular dietary patterns (i.e., the Meat, Healthy, and High-sugar patterns) are associated with the risk of CRC in the NL population. This specific diet-disease relationship could be used for guiding the promotion of healthy eating for primary prevention of CRC in this population.