Among the most frequently consumed beverages worldwide, coffee is rich in antioxidants, with one cup providing 350 mg of phenolic compounds.  A team of researchers from the University of Vienna (Austria), the University of Belgrade (Serbia), and other European institutions enrolled 38 men and women for a controlled intervention trial with a cross-over design. Each subject consumed 800 ml of paper-filtered coffee or water daily over 5 days. The researchers found that coffee reduced the oxidative damage to DNA, as measured by a decreased formation of oxidized purines, by 12.3%. No significant changes in levels of antioxidants in the blood, or levels of reactive oxygen species in the blood, were observed.  The team concludes that: “Overall, the results indicate that coffee consumption prevents endogenous formation of oxidative DNA-damage in human, this observation may be causally related to beneficial health effects of coffee seen in earlier studies.”