The relationship of coffee and green tea consumption with high-sensitivity C-reactive protein in Japanese men and women

Background: Circulating high-sensitivity C-reactive protein (CRP) is a good marker of chronic low-grade inflammation. The few studies that have addressed the relationship between coffee consumption and CRP concentrations report inconsistent findings. The authors of this study examined the relationship between coffee and green tea consumption and serum concentrations of CRP, and the interaction with alcohol consumption, smoking, and obesity in a large population of free-living Japanese men and women. Methods: Study subjects were 10,325 men and women, 49-76 years of age, living in Fukuoka City who participated in a baseline survey of a cohort study on lifestyle-related diseases. Coffee and green tea consumption and other lifestyle characteristics were assessed using a structured questionnaire. Anthropometric measurements and venous blood samples were also included. Results: CRP concentrations were progressively lower with increasing levels of coffee consumption, after adjustment for smoking and other covariates (p for trend = 0.03) in men, but not in women. Stratified analysis indicated that this inverse association was primarily limited to men with a high consumption of alcohol (>= 50 g/day). Green tea consumption showed no measurable relationship with CRP concentrations in either men or women. Conclusions: Coffee may be protective specifically against alcohol-induced hepatic inflammation. Further studies are warranted in different populations. Clin Chem Lab Med 2010;48:849-54.