Researchers from the University of Vienna, Nestlé, and the University of Belgrade report that paper-filtered coffee – the most widely consumed form in Central Europe and the US – may protect against oxidative DNA-damage.
No changes in overall antioxidants status of the 38 participants were observed, according to findings published in Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis.
“It is conceivable that indirect effects such as reduced uptake of glucose via the gastrointestinal tract, which was seen with specific types of coffee and with chlorogenic acids may play a role as it is known that alterations of the energy metabolism may lead to reduced reactive oxygen species formation in the mitochondria,” wrote the researchers.
The study was funded by the Institute of Scientific Information on Coffee (ISIC) – a scientific consortium of European coffee companies.
A recent review by Mario Ferruzzi from Purdue University noted that coffee is one of the richest sources of polyphenols in the Western diet, with one cup of the stuff providing 350 milligrams of phenolics. Of these, the most abundant compounds coffee are chlorogenic acids, making up to 12 per cent of the green coffee bean. The most abundant of these compounds is caffeic acid (Physiology & Behavior, 2010, Vol. 100, pp. 33-41).
“A better understanding of how the beverage composition impacts phenolic profiles and their bioavailability is critical to development of beverage products designed to deliver specific health benefits,” he added.
The beverage, and its constituent ingredients, has come under increasing study with research linking it to reduced risk of diabetes, and improved liver health.
Coffee, one of the world's largest traded commodities produced in more than 60 countries and generating more than $70bn in retail sales a year, continues to spawn research and interest, and has been linked to reduced risks of certain diseases, especially of the liver and diabetes.
The researchers recruited 38 people to participate in their controlled intervention trial with a cross-over design. The subjects were assigned to drink either 800 ml coffee or water daily for five days. Various measures of DNA damage were used.
At the end of the study, a reduction in DNA damage, as measured by a reduction in the formation of oxidised purines of 12.3 percent was observed in the coffee drinkers.
On the other hand, no significant changes in levels of antioxidants in the blood, or levels of reactive oxygen species in the blood were observed,
“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,” concluded the researchers.
From bean to leaf
Only last week, we reported on findings from a human study that indicated that green tea may also reduce DNA damage. Researchers from The Hong Kong Polytechnic University reported in the British Journal of Nutrition that combined results from a human supplementation trial and an in vitro study indicated a 20 percent reduction in levels of DNA damage.
“The results indicate that green tea has significant genoprotective effects and provide evidence for green tea as a ‘functional food’,” wrote the Hong Kong-based researchers.
Source: Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
Published online ahead of print, doi: 10.1016/j.mrfmmm.2010.08.003
“Impact of paper filtered coffee on oxidative DNA-damage: Results of a clinical trial“
Authors: M. Misik, C. Hoelzl, K-H. Wagner, C. Cavin, et al.