Coffee consumption is associated with a lower risk of
type 2 diabetes. We tested the hypothesis that this is mediated by
incretin hormones by measuring the acute effects of decaffeinated
coffee and
coffee components on
GLP-1 and GIP concentrations. A randomized cross-over trial of the effects of 12 g decaffeinated
coffee, 1 g
chlorogenic acid, 500 mg
trigonelline, and placebo on total and intact
GLP-1 and GIP concentrations during an oral
glucose tolerance test took place in fifteen
overweight men. No treatment significantly affected the overall
GLP-1 or GIP secretion pattern following an OGTT relative to placebo. Decaffeinated
coffee slightly increased total
GLP-1 concentration 30 minutes after ingestion (before the OGTT) relative to placebo (2.7 pmol/L, p = 0.03), but this change did not correspond with changes in
glucose or insulin secretion. These findings do not support the hypothesis that
coffee acutely improves
glucose tolerance through effects on the secretion of
incretin hormones. Chronic effects of
coffee and its major components still need to be investigated.