Coffee contains several bioactive compounds relevant to colon physiology. Although coffee intake is a proposed protective factor for colorectal cancer, current evidence remains inconclusive.
We investigated the association between coffee consumption and risk of colorectal cancer in 5,145 cases and 4,097 controls from the Molecular Epidemiology of Colorectal Cancer (MECC) study, a population-based case–control study in northern Israel. We also examined this association by type of coffee, by cancer site (colon and rectum), and by ethnic subgroup (Ashkenazi Jews, Sephardi Jews, and Arabs). Coffee data were collected by interview using a validated, semi-quantitative food frequency questionnaire.
Coffee consumption was associated with 26% lower odds of developing colorectal cancer [OR (drinkers vs. non-drinkers), 0.74; 95% confidence interval (CI), 0.64–0.86; P < 0.001]. The inverse association was also observed for decaffeinated coffee consumption alone (OR, 0.82; 95% CI, 0.68–0.99; P = 0.04) and for boiled coffee (OR, 0.82; 95% CI, 0.71–0.94; P = 0.004). Increasing consumption of coffee was associated with lower odds of developing colorectal cancer. Compared with <1 serving/day, intake of 1 to <2 servings/day (OR, 0.78; 95% CI, 0.68–0.90; P < 0.001), 2 to 2.5 servings/day (OR, 0.59; 95% CI, 0.51–0.68; P < 0.001), and >2.5 servings/day (OR, 0.46; 95% CI, 0.39–0.54; P < 0.001) were associated with significantly lower odds of colorectal cancer (Ptrend < 0.001), and the dose–response trend was statistically significant for both colon and rectal cancers.
Coffee consumption may be inversely associated with risk of colorectal cancer in a dose–response manner.