Decaffeinated Coffee May Impair Glucose Metabolism
Study finds higher glucose and insulin levels shortly after decaffeinated coffee consumption
FRIDAY, Feb. 12 (HealthDay News) -- Although earlier research has linked decaffeinated coffee to a lower risk of type 2 diabetes, the beverage has been found to impair glucose metabolism in healthy young men, but less so than caffeinated beverages, according to research published in the February issue of Diabetes Care.
James A. Greenberg, Ph.D., of the University of New York in New York City, and colleagues analyzed data from 11 healthy men, mean age 23.5 years, who underwent two-hour oral glucose tolerance testing on four occasions. An hour before each test, they drank either caffeinated or decaffeinated coffee, caffeine in warm water, or water as a placebo.
During the first hour of the oral glucose tolerance test, the researchers found that glucose and insulin were significantly higher for decaffeinated coffee than placebo. During the entire test, insulin sensitivity index was significantly higher for decaffeinated coffee than for caffeine. Glucose-dependent insulinotropic polypeptide (GIP) was significantly lower for decaffeinated coffee than caffeine and placebo 60 minutes after consumption, but GIP wasn't thought to play a role in the study's findings.
"[Our findings] suggest that caution is needed in the quest to harness coffee's potential to reduce the risk of diabetes, demonstrated in epidemiological studies," the authors write. "In conclusion, our human trial appears to be the first to find that decaffeinated coffee can acutely impair glucose metabolism, but less than caffeine, in healthy young men."