Coffee and tea consumption in relation to inflammation and basal glucose metabolism in a multi-ethnic Asian population: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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).</p> <p>Results</p> <p>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; <it>P_trend</it>= 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; <it>P_trend</it>= 0.042).</p> <p>Conclusions</p> <p>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.</p

Intake of coffee, caffeine and other methylxanthines and risk of Type I vs Type II endometrial cancer

BACKGROUND: Coffee and other sources of methylxanthines and risk of Type I vs Type II endometrial cancer (EC) have not been evaluated previously. METHODS: Prospective cohort of 23 356 postmenopausal women with 471 Type I and 71 Type II EC cases. RESULTS: Type I EC was statistically significantly associated with caffeinated (relative risk (RR)=0.65 for 4+ cups per day vs ⩽1 cup per month: 95% confidence interval (CI): 0.47–0.89) but not decaffeinated (RR=0.76; 95% CI: 0.50–1.15) coffee intake; there were no associations with tea, cola or chocolate, or for Type II EC. The inverse association with caffeinated coffee intake was specific to women with a body mass index 30+ kg m(−2) (RR=0.56; 95% CI: 0.36–0.89). CONCLUSION: Coffee may protect against Type I EC in obese postmenopausal women