UC San Diego

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.