Coffee consumption rapidly reduces background DNA strand breaks in healthy humans: Results of a short‐term repeated uptake intervention study

Scope Intervention studies provide evidence that long‐term coffee consumption correlates with reduced DNA background damage in healthy volunteers. Here, we report on short‐term kinetics of this effect, showing a rapid onset after normal coffee intake. Methods and results In a short‐term human intervention study, we determined the effects of coffee intake on DNA integrity during 8 h. Healthy male subjects ingested coffee in 200 mL aliquots every second hour up to a total volume of 800 mL. Blood samples were taken at baseline, immediately before the first coffee intake and subsequently every 2 h, prior to the respective coffee intake. DNA integrity was assayed by the comet assay. The results show a significant ( p < 0.05) reduction of background DNA strand breaks already 2 h after the first coffee intake. Continued coffee intake was associated with further decrements in background DNA damage within the 8 h intervention ( p < 0.01 and p < 0.001, respectively). Mean tail intensities (TIs%) decreased from 0.33 TI% (baseline, 0 h) to 0.22 TI% (within 8 h coffee consumption). Conclusion Repeated coffee consumption was associated with reduced background DNA strand breakage, clearly measurable as early as 2 h after first intake resulting in a cumulative overall reduction by about one‐third of the baseline value.