Decaffeinated coffee and glucose metabolism in young men.
OBJECTIVE
The epidemiological association between coffee drinking and decreased risk of type 2 diabetes is strong. However, caffeinated coffee acutely impairs glucose metabolism. We assessed acute effects of decaffeinated coffee on glucose and insulin levels.


METHODS
This was a randomized, cross-over, placebo-controlled trial of the effects of decaffeinated coffee, caffeinated coffee, and caffeine on glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) levels during a 2-h oral glucose tolerance test (OGTT) in 11 young men.


RESULTS
Within the first hour of the OGTT, glucose and insulin were higher for decaffeinated coffee than for placebo (P < 0.05). During the whole OGTT, decaffeinated coffee yielded higher insulin than placebo and lower glucose and a higher insulin sensitivity index than caffeine. Changes in GIP could not explain any beverage effects on glucose and insulin.


CONCLUSIONS
Some types of decaffeinated coffee may acutely impair glucose metabolism but less than caffeine.
Greenberg
James A
JA
Department of Health and Nutrition Sciences, Brooklyn College of the City, University of New York, New York, New York, USA. jamesg@brooklyn.cuny.edu
Owen
David R
DR
Geliebter
Allan
A
D000328:Adult; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D002110:Caffeine / Q000032:analysis / Q000494:pharmacology*; D003069:Coffee; D005951:Glucose Tolerance Test; D005972:Glutaminase / Q000097:blood / Q000187:drug effects; D006801:Humans; D007328:Insulin / Q000097:blood; D047908:Intracellular Signaling Peptides and Proteins / Q000097:blood / Q000187:drug effects; D008297:Male; D010919:Placebos
D001786:Blood Glucose; D003069:Coffee; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D010919:Placebos; C421249:TAX1BP3 protein, human; D002110:Caffeine; D005972:Glutaminase