The researchers found that the more coffee participants consumed each day, the less likely they were to develop melanoma during the follow-up period. Drinking four cups of coffee a day, for example, was associated with a 20% lower risk of melanoma, the team reports.
These results remained even after accounting for participants' age, sex, body mass index (BMI), alcohol intake, smoking history and ultraviolet (UV) radiation exposure - a primary risk factor for skin cancer.
The team notes the association was only found among participants who consumed caffeinated coffee, not decaffeinated. In addition, coffee only appeared to reduce the risk of malignant melanoma, not melanoma in situ - in which melanoma cells have not spread beyond the outer cells of the skin.
Commenting on their findings, the researchers say:
"Higher coffee intake was associated with a modest decrease in risk of melanoma in this large US cohort study. Additional investigations of coffee intake and its constituents, particularly caffeine, with melanoma are warranted."
The team believes this "modest" reduction in melanoma risk from coffee consumption, however, may have big effects. "Because of its high disease burden, lifestyle modifications with even modest protective effects may have a meaningful impact on melanoma morbidity," they add.