Eating frequency and risk of colorectal cancer

Case-control studies have found elevated risk of colorectal cancer with higher eating frequency. The present analyses, the first to examine this association using prospectively collected information, utilized nationally representative data from the Epidemiologic Follow-Up Study of the First National Health and Nutrition Examination Survey (NHEFS). The study population included 9,978 subjects followed from 1982-84 to 1992. Colorectal cancer cases (n = 141) were identified by self-report, hospital records, and death certificates. Interviews conducted in 1982-84 provided information on meal and snack frequencies and covariates of interest. Relative risk (RR) of colorectal cancer and 95% confidence intervals (CI) were estimated using Cox proportional hazards models adjusted for age, gender, and race and energy, alcohol, total fat, and fiber intake. Compared with those eating < 3 times/day, those eating 3-4 times/day had an RR of 0.66 (95% CI = 0.42-1.03) and those eating > 4 times/day had an RR of 0.74 (95% CI = 0.41-1.32). The association was due to decreased risk with more meals rather than more snacks per day. Given limitations of previous studies as well as the possibility of a protective effect of higher eating frequency through improved glycemic control, the present findings suggest that the influence of eating frequency on colorectal cancer risk is more complex than has been previously supposed and merits additional study.