Coffee has been associated with a variety of health benefits, such as promoting a healthy heart, reducing the risk of skin cancer, and protecting against type 2 diabetes and Parkinson’s. A recent study, published Feb. 2015 in The European Journal of Nutrition, has found that the consumption of coffee substantially lowered the level of spontaneous DNA strand breaks in white blood cells (WBC). Levels of spontaneous DNA strand breaks are a well established marker of health risk.

“We conclude that regular coffee consumption contributes to DNA integrity.” says Tamera Bakuradze of the Division of Food Chemistry, Toxicology, and Molecular Nutrition at the University of Kaiserslautern in Germany. Consuming a blend known to be rich in active compounds experienced fewer breaks to the DNA strands in white blood cells when compared with controls. The coffee used in the study was a dark roast that provided high amounts of caffeoylquinic acids and the roast product N-methylpyridinium. 84 healthy male participants consumed 3 cups of fresh coffee at staggered intervals for four weeks in this German study. 

Previous research has shown that coffee consumption can decrease the instances of oxidative damage in white blood cells. This damage is caused by an imbalance between the production of reactive oxygen species called ‘free radicals’ – atoms, molecules, or ions that end up with one or more unpaired electrons, which makes them highly reactive with other cellular structures – and the cell’s ability to counteract their harmful effects. Unregulated free radicals can damage several components of a cell, including its proteins, lipids, and DNA. The body cannot always repair damaged DNA, or cannot repair it properly, which can lead to compromised function, or mutations. If serious enough, the mutations can develop into cancer, and the lack of function will result in accelerated cellular ageing.

The results correlate to findings of previous research. A study from 2007 showed marked protection against oxidative DNA damage after just five days of consuming freshly prepared filtered coffee brew, and another from 2010, showed a very slight reduction of oxidative DNA strand breaks in the volunteers’ lymphocytes after drinking instant coffee. “Taken together, the observed DNA protective effects associated with coffee consumption may be considered beneficial to human health,” Bakuradze’s team says of the body of research related to coffee consumption and DNA integrity.