Numerous studies have suggested that drinking coffee might have a variety of health benefits, including a reduction in the risk of some cancers. This potential reduction in cancer risk has been thought to be due to the polyphenolic antioxidants present in coffee. Because of the level of coffee consumption by the population, coffee appears to be one of the richest sources of antioxidants, particularly the antioxidant caffeic acid, in our diet. While the potential health benefits of coffee are thought to be due to its antioxidants, the full mechanism remains uncertain.
A new cancer research study tested the idea that coffee's potential health benefits might be due at least in part to protection of cellular DNA from oxidative damage. To test their theory, the study investigators assigned 38 volunteers to either drink 800 ml (nearly 3.5 cups) of coffee per day or 3.5 cups of water per day over a 5-day period. To assess the antioxidant and DNA effects of coffee consumption, the study investigators measured DNA damage in circulating white blood cells and measured blood levels of several markers of antioxidant status. The researchers reported that even though coffee consumption did not change any of the antioxidant markers in the blood, DNA damage was reduced by about 12%.
Since DNA damage and the inability to repair it can lead to DNA mutation and the development of cancer, factors that can protect DNA from oxidative damage have the potential to reduce cancer risk. This new cancer research study suggests that daily consumption of coffee and its antioxidant polyphenols might protect DNA from oxidative damage. This DNA-protective effect of coffee is likely to be one of the reasons for the possible health benefits of moderate coffee consumption.