The relationship between usual coffee consumption and serum C-reactive protein level in a Japanese female population

Background: Usual coffee consumption may decrease insulin resistance and type 2 diabetes incidence, and reduce cardiovascular disease risk. As a mechanism, coffee-induced lower levels of C-reactive protein (CRP), a marker for the development of these diseases, can be considered. The associations between coffee consumption and CRP should be established by studies on various populations, yet studies in Japanese people, who do not necessarily consume as much coffee daily, are limited. Methods: In total, 459 community-living Japanese women, aged 23-83 years, were investigated. Clinical data including age, body mass index, blood pressure, HbA(1c), serum high sensitive CRP (hsCRP) and lifestyle habits, such as coffee consumption, were included in the analyses. All analyses were performed in two groups of the population, i.e., age < 60 and >= 60 years. Results: Significantly lower levels of hsCRP were observed in the group of >= 1 cup/day than in that of < 1 cup/day in the respective groups of < 60 years (p=0.001) and >= 60 years (p < 0.0001). In multiple regression analysis, coffee consumption was significantly, independently and inversely correlated to log-hsCRP in the respective groups of < 60 years (p=0.017) and >= 60 years (p=0.0001). Conclusions: It was noteworthy that the benefits of coffee consumption, even if >= 1 cup/day, on serum hsCRP levels were confirmed in Japanese women, following similarly to other ethnic data.