Coffee consumption has been suggested, in animal studies, to inhibit the progression of sarcopenia, possibly through its anti-inflammatory effects; however, few studies have been carried out in humans. We aimed to examine whether coffee consumption was related to indicators of sarcopenia in a Japanese population, and whether the association was mediated by reduced inflammation.
This study was a cross-sectional design. Participants were community residents (n = 6369) aged 45-74 years. We measured skeletal muscle mass index (SMI; kg/m2 ) by a bioelectrical impedance method, and grip strength with a Smedley-type dynamometer. Habitual coffee consumption was assessed by a self-administered questionnaire. Serum high-sensitivity C-reactive protein was measured as an inflammatory marker. The association between habitual coffee consumption and SMI or grip strength was analyzed with a linear regression model adjusted for covariates.
A significant positive association was found between coffee consumption and SMI (men: β = 0.023; Ptrend = 0.004, women: β = 0.011; Ptrend = 0.012). Further adjustment for high-sensitivity C-reactive protein did not materially alter the results (men: β = 0.023; Ptrend = 0.005, women: β = 0.009; Ptrend = 0.024). The relationship between coffee consumption and grip strength did not reach statistical significance; however, a positive trend was observed (men: β = 0.208; Ptrend = 0.085, women: β = 0.092; Ptrend = 0.167).
We found that coffee consumption was positively associated with SMI independently of inflammation in middle-aged and older Japanese people. Reduced inflammation by coffee does not seem to be an important mediator, and further investigations are required to explore the mechanisms of this association.