Could your morning cup of coffee, afternoon tea or diet cola reduce your risk of skin cancer? Data from two large observational studies totaling nearly 113,000 men and women show that those consuming the most caffeine were significantly less likely to develop basal cell carcinoma.
Jalali Han, PhD, of Harvard, and colleagues reviewed data from the Nurses Health Study and the Health Professionals Follow-up Study. Over more than 20 years of followup, 22,786 participants developed basal cell carcinoma.
Caffeine intake was estimated based on reported intake of regular coffee, tea, cola and chocolate, and ranged from 8 to 584 milligrams daily. Participants consuming as much caffeine as found in three or more cups of coffee per month were at 17% lower risk than those drinking the equivalent of less than one cup. Overall, as caffeine intake rose, risk of basal cell carcinoma dropped. Coffee, which accounted for more than three-quarters of the caffeine consumption, was also specifically associated with lower risk.
Previous animal studies, scientists noted, have shown that topical application of caffeine induces the normal cell death that helps counter tumors. Observational studies in humans of skin cancer and coffee or tea have been inconsistent, but these have failed to distinguish between regular and decaf beverages. The new study did not find a protective association with other forms of skin cancer.
Before you replace your sunscreen with latts, however, Joel B. Mason, MD, director of Tufts HNRCA Vitamins and Carcinogenesis Laboratory, cautions, This is a good example of the dictum that epidemiological research is good at generating hypotheses, but not proving them. It is an interesting association, but it cannot prove causality.
TO LEARN MORE: Cancer Research, July 1, 2012; abstract at cancerres.aacrjournals.org/content/72/13/3282.abstract.