It doesn't just taste delicious and smell divine - coffee is also thought to be associated with a variety of health benefits, such as promoting a healthy heart, protecting against type 2 diabetes and Parkinson’s, and reducing the risk of skin cancer, to name just a few. Now, to add to this ever-growing list, a bunch of scientists has found that regularly drinking coffee can contribute to the integrity of our DNA.
During the new investigation, scientists found that those 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. Although the study was small and only involved men, their findings back up previous research which found that coffee consumption was associated with a reduction in a type of damage in the same cells, called oxidative damage, which can harm DNA. The research can be found in the European Journal of Nutrition.
The main reason that coffee has grabbed so much attention in recent years is because it’s known to be rich in bioactive compounds, many of which are present in the green bean but some are also generated by processing such as the roasting phase. These chemicals, in particular the chlorogenic acids, are known to have a variety of health-promoting characteristics, such as potent antioxidant and anti-inflammatory properties. For example, caffeoylquinic acid (CQA) increases the levels of antioxidant enzymes present in the cell and also mops up harmful molecules called reactive oxygen species (ROS).
Although ROS -- highly reactive molecules containing oxygen-- are produced during normal metabolism and play a variety of important roles, too much can damage proteins in the cell and induce breaks in our DNA, which can occur when our inbuilt antioxidant systems don’t function properly. While these breaks can often be repaired by cellular mechanisms, if the damage is extensive it can lead to mutations and even cancer.
Previous work found that regular coffee consumption seemed to decrease oxidative damage in white blood cells, members of the immune system that help protect against disease and infection. However, studies had yet to demonstrate whether drinking coffee can reduce spontaneous DNA strand breaks in humans, an established marker of health risk, which can result from this kind of damage.
To find out more, scientist enrolled 84 healthy men into a new study, half of whom were given 750 ml of a special roasted and blended Arabica coffee brew daily for 4 weeks, while the other half were given the same amount of water. All volunteers were asked to keep their usual dietary habits throughout the study and to avoid other caffeine-containing products. Blood was taken at regular intervals throughout the study for analysis, 2 hours after the ingestion of coffee or water.
At the start of the study, both groups exhibited similar levels of spontaneous DNA breaks; however, during the intervention phase, breaks slightly increased in the control group but decreased in those drinking coffee, leading to a substantial 27% overall difference. These apparent protective effects, the researchers say, could be considered beneficial to human health. Of course, this doesn’t mean that drinking coffee alone will keep you healthy, but it does seem to add to the growing body of evidence that coffee could delay certain diseases associated with this particular type of damage.