Coffee intake is associated with lower levels of oxidative DNA damage and decreasing body iron storage in healthy women

Habitual coffee drinking has been linked to a lower risk for some forms of cancer, but the mechanism remains elusive. Coffee may decrease oxidative DNA damage, an important pathway to carcinogenesis. We examined the association between coffee consumption and urinary 8-hydroxydeoxyguanosine (8-OHdG) concentrations, a biomarker of systemic oxidative DNA damage and repair, in 507 healthy subjects (298 men and 209 women aged 21-67 yr) while adjusting for age, sex, smoking status, body mass index, job type, and fasting blood glucose in multivariable regression models. The association with green tea consumption was also assessed. Urinary 8-OHdG concentrations tended to decrease with coffee consumption in women (trend P = 0.046), with women drinking 2-3 cups of coffee per day showing the lowest mean of urinary 8-OHdG concentrations. This association was largely attenuated after further adjustment for serum ferritin concentrations, a marker of body iron storage (trend P = 0.96). Green tea consumption was not associated with urinary 8-OHdG concentrations. Coffee drinking may be associated with decreased systemic oxidative DNA damage through decreasing body iron storage in women.