Coffee and tea consumption in relation to inflammation and basal glucose metabolism in a multi-ethnic Asian population: a cross-sectional study
1 Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 05-02, 28 Medical Drive, Singapore 117456
2 Center for Molecular Epidemiology, National University of Singapore, #05-02, 28 Medical Drive, Singapore 117456
3 Department of Epidemiology and Public Health, National University of Singapore, Yong Loo Lin School of Medicine, 16 Medical Drive, Singapore 117597
4 Department of Medicine, National University of Singapore, 1E, Kent Ridge Road, NUHS Tower Block Level 10, Singapore 119228
5 Department of Epidemiology and Public Health and Medicine, Yong Loo Lin School of Medicine, National University of Singapore Block MD3 #03-17, 16, Medical Drive, Singapore. 117597 and Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, 02115, USA
Nutrition Journal 2011, 10:61 doi:10.1186/1475-2891-10-61Published: 2 June 2011
Higher coffee consumption has been associated with a lower risk of type 2 diabetes in cohort studies, but the physiological pathways through which coffee affects glucose metabolism are not fully understood. The aim of this study was to evaluate the associations between habitual coffee and tea consumption and glucose metabolism in a multi-ethnic Asian population and possible mediation by inflammation.
We cross-sectionally examined the association between coffee, green tea, black tea and Oolong tea consumption and glycemic (fasting plasma glucose, HOMA-IR, HOMA-beta, plasma HbA1c) and inflammatory (plasma adiponectin and C-reactive protein) markers in a multi-ethnic Asian population (N = 4139).
After adjusting for multiple confounders, we observed inverse associations between coffee and HOMA-IR (percent difference: - 8.8% for ≥ 3 cups/day versus rarely or never; Ptrend = 0.007), but no significant associations between coffee and inflammatory markers. Tea consumption was not associated with glycemic markers, but green tea was inversely associated with plasma C-reactive protein concentrations (percent difference: - 12.2% for ≥ 1 cup/day versus < 1 cup/week; Ptrend = 0.042).
These data provide additional evidence for a beneficial effect of habitual caffeinated coffee consumption on insulin sensitivity, and suggest that this effect is unlikely to be mediated by anti-inflammatory mechanisms.