Coffee Consumption and the Incidence of Colorectal Cancer in Women

Background. Higher coffee consumption has been associated with decreased incidence of colorectal cancer. Our objective was to examine the relationship of coffee intake to colorectal cancer incidence in a large observational cohort of postmenopausal US women. Methods. Data were collected for the Women's Health Initiative Observational Study providing a follow-up period of 12.9 years. The mean age of our sample (N = 83,778 women) was 63.5 years. Daily coffee intake was grouped into 3 categories: None, moderate (>0-<4 cups), and high (4+ cups). Proportional hazards modeling was used to evaluate the relationship between coffee intake and colorectal cancer. Results. There were 1,282 (1.53%) new cases of colorectal cancer during follow-up. Compared to nondrinkers, moderate and high coffee drinkers had an increased incidence of colorectal cancer in multivariate analysis (HR 1.15, 1.02-1.29; HR 1.14, 0.93-1.38). Moderate drip brew coffee intake (HR 1.20, 1.05-1.36) and high nondrip brew coffee intake (HR 1.43, 1.01-2.02) were associated with increased odds. Conclusion. Our results suggesting increased incidence of colorectal cancer associated with higher coffee consumption contradict recent meta-analyses but agree with a number of other studies showing that coffee increases risk or has no effect. Brew method results are novel and warrant further research.