PMC7528046_01
Effect of coffee on postprandial interstitial glucose levels. (A) The y-axis shows the postprandial interstitial glucose levels measured every 15 minutes using the FreeStyle Libre glucose monitor (Abbott Diabetes Care Ltd, Witney, United Kingdom), whereas the x-axis shows time (in minutes). The light green square indicates when the meal was consumed and the purple square indicates when the coffee was consumed. The black line with circles represents the data obtained when no coffee was consumed (control); the red line with circles represents Kenyan coffee consumption, light blue line with circles represents Tanzanian coffee consumption, and blue line with circles reflects Ethiopian coffee intake. (B) The black bar represents the data obtained when no coffee was consumed (control); the red bar represents Kenyan coffee consumption, the light blue bar represents Tanzanian coffee intake, and the blue bar represents Ethiopian coffee intake. The area under the curve (AUC) of the experiment with Kenyan coffee consumption was significantly smaller than those of the experiments involving Tanzanian, Ethiopian, or no coffee consumption (P < 0.01) in periods b and c. Period a represents the time lapsing from baseline until the beginning of Kenyan, Tanzanian, or Ethiopian coffee intake, whereas period b represents the period reflecting the time lapsing from the beginning of coffee drinking to the end of the experiment. Period c represents periods a + period b and thereby reflects the entire experimental period. Statistical significance was observed between * and ** (P < 0.01). Each experiment was repeated 3 times. (C) Photographs of the coffee beans used in the present study.
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We selected coffee beans with similar roasted properties as shown in Figure 1C.