- A 2011 randomised controlled trial showed consumption of ±5 cups of caffeinated coffee per day increased adiponectin and interleukin-6 concentrations vs. abstention, possibly reflecting anti-inflammatory and insulin sensitizing effects. Furthermore, consumption of decaffeinated coffee decreased fetuin-A concentrations, a biomarker for inflammation and liver function. No significant differences were found between treatment groups for measures of glucose tolerance, insulin sensitivity and insulin secretion, suggesting that improvements in adipocyte and liver function, as indicated by changes in adiponectin and feutin-A concentrations, may contribute to beneficial metabolic effects of long-term coffee consumption49
- A 2012 study in a Japanese population examined the association between coffee and glucose tolerance and the effect of modification of serum γ-glutamyltransferase on this association found coffee drinking to be protective against glucose intolerance. Furthermore, they suggested that the observed possible effect modification of serum γ-glutamyltransferase on the protective association between coffee and type 2 diabetes warrants further research50
