Diet quality indices and gastrointestinal cancer risk: results from the Lifelines study

Objective To investigate the long-term association between four dietary quality indices and the risk of gastrointestinal (GI) cancer. Methods Baseline details of the dietary intake of participants, assessed by a single food frequency questionnaire from the prospective Lifelines population-based cohort were translated to diet quality scores using several dietary and dietary-lifestyle indices. Incident cases of GI cancer were then assessed by linkage to the Dutch nationwide histo-cytopathology registry. The association between GI cancer risk and diet quality (defined as higher quintiles on dietary indices compared to the first quintile) was assessed by multivariable Cox proportional hazard models. Results We included 72,695 participants aged 51.20 +/- 8.71 years with a median follow-up to cancer diagnosis of 8 years (interquartile range 2 years). During follow-up, 434 colorectal cancers and 139 upper GI cancers were diagnosed. There was a significant reduction in colorectal cancer risk for high categories in the American Cancer Society (ACS) Index (hazard ratio 0.62; 95% CI 0.46-0.84). However, high dietary index scores were not associated with strong beneficial effects on upper GI cancer risk. Conclusion High quintiles on the ACS Index were associated with a significantly reduced risk of colorectal cancer. This index may be of use in a colorectal cancer prevention program.

Automated summary

The study found that high scores on the American Cancer Society (ACS) Index were significantly associated with a reduced risk of colorectal cancer, but high dietary index scores did not show strong beneficial effects on upper gastrointestinal cancer risk.