DÜSSELDORF, Germany—Coffee consumption appeared to have beneficial effects on subclinical inflammation and high-density lipoprotein (HDL) cholesterol, but no changes in glucose metabolism were found (Am J Clin Nutr. Feb. 24, 2010). Habitual coffee drinkers (n = 47) refrained for one month from coffee drinking; in the second month they consumed four cups of filtered coffee/d and in the third month eight cups of filtered coffee/d (150 mL/cup).
Coffee consumption led to an increase in coffee-derived compounds, mainly serum caffeine, chlorogenic acid and caffeic acid metabolites. Significant changes were also observed for serum concentrations of interleukin-18, 8-isoprostane and adiponectin (eight compared with zero cups coffee/d). Serum concentrations of total cholesterol, HDL cholesterol and apolipoprotein A-I increased significantly by 12 percent, 7 percent and 4 percent, respectively; whereas the ratios of low-density lipoprotein (LDL) to HDL cholesterol and of apolipoprotein B to apolipoprotein A-I decreased significantly by 8 percent and 9 percent, respectively (eight compared with zero cups coffee/d). No changes were seen for markers of glucose metabolism in an oral-glucose-tolerance test. Many coffee-derived methylxanthines and caffeic acid metabolites appear to be useful as biomarkers of coffee intake.
