Moderate coffee consumption is associated with a reduced risk for diabetes mellitus type II, several types of cancer or Parkinson’s disease, as prospective cohort studies have shown. Since reactive oxygen species are believed to be involved in the pathogenesis of these diseases, antioxidants in coffee might contribute to this risk reduction.

Veronika Somoza, University of Vienna, Austria, and colleagues found that a dark roast coffee beverage (CB) rich in N-methylpyridinium (NMP) and low in chlorogenic acids has stronger antioxidant effects on human erythrocytes than a CB prepared from a light roast with opposite proportions. This means it restored red blood cell vitamin E and glutathione concentrations in healthy volunteers.
The NMP-CB intervention also reduced the body weight in pre-obese subjects, indicating a significant potential for body weight control by dark roast coffee brews containing high amounts of NMP.

Future studies have to prove whether these effects can be attributed to NMP or to other coffee constituents.

• Dark roast coffee is more effective than light roast coffee in reducing body weight, and in restoring red blood cell vitamin E and glutathione concentrations in healthy volunteers,
  Christine Kotyczka, Ute Boettler, Roman Lang, Herbert Stiebitz, Gerhard Bytof, Ingo Lantz, Thomas Hofmann, Doris Marko, Veronika Somoza,
  Mol. Nutr. Food Res. 2011, 55.
  DOI: 10.1002/mnfr.201100248