A new American Cancer Society study finds a strong inverse association between caffeinated coffee intake and oral/pharyngeal cancer mortality. The authors say people who drank more than four cups of caffeinated coffee per day were at about half the risk of death of these often fatal cancers compared to those who only occasionally or who never drank coffee. The study is published online in the American Journal of Epidemiology. The authors say more research is needed to elucidate the biologic mechanisms that could be at work.
Previous epidemiologic studies have suggested that coffee intake is associated with reduced risk of oral/pharyngeal cancer. To explore the finding further, researchers examined associations of caffeinated coffee, decaffeinated coffee, and tea intake with fatal oral/pharyngeal cancer in the Cancer Prevention Study II, a prospective U.S. cohort study begun in 1982 by the American Cancer Society.
Among 968,432 men and women who were cancer-free at enrollment, 868 deaths due to oral/pharyngeal cancer occurred during 26 years of follow-up. The researchers found consuming more than four cups of caffeinated coffee per day was associated with a 49 percent lower risk of oral/pharyngeal cancer death relative to no/occasional coffee intake (RR 0.51, 95% confidence interval [CI] 0.40-0.64). A dose-related decline in relative risk was observed with each single cup per day consumed. The association was independent of sex, smoking status, or alcohol use. There was a suggestion of a similar link among those who drank more than two cups per day of decaffeinated coffee, although that finding was only marginally significant. No association was found for tea drinking.