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. 2012:2012:207426.
doi: 10.1155/2012/207426. Epub 2012 Nov 5.

Effects of 16-week consumption of caffeinated and decaffeinated instant coffee on glucose metabolism in a randomized controlled trial

Keizo Ohnaka  1 , Mizuko Ikeda, Takako Maki, Tomoko Okada, Takao Shimazoe, Masahiro Adachi, Masatoshi Nomura, Ryoichi Takayanagi, Suminori Kono
Affiliations

Effects of 16-week consumption of caffeinated and decaffeinated instant coffee on glucose metabolism in a randomized controlled trial

Keizo Ohnaka et al. J Nutr Metab. 2012.

Abstract

Objective. Observational studies have shown a protective association between coffee consumption and type 2 diabetes mellitus whereas caffeine or caffeinated coffee acutely deteriorates glucose tolerance. We investigated the effects of chronic drinking of instant coffee on glucose and insulin concentrations during a 75 g oral glucose tolerance test. Methods. Overweight men with a mild-to-moderate elevation of fasting plasma glucose were randomly allocated to a 16-week intervention of consuming 5 cups of caffeinated (n = 17) or decaffeinated (n = 15) instant coffee per day or no coffee (n = 13). Results. The caffeinated coffee group showed statistically significant decreases in the 2-hour concentrations and the area under the curve of glucose while neither decaffeinated coffee nor coffee group showed such a change. Waist circumstance decreased in the caffeinated coffee group, increased in the decaffeinated coffee group, and did not change in the noncoffee group (P = 0.002). With adjustment for the change in waist circumference, caffeinated and decaffeinated coffee consumption were associated with a modest decrease in the postload glucose levels. Conclusion. Both caffeinated and decaffeinated coffee may be protective against deterioration of glucose tolerance.

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Figures

Figure 1
Figure 1
Trial profile.
Figure 2
Figure 2
Caffeine concentrations (μM) in saliva collected at unannounced visits in the first 8 weeks (a) and the second 8 weeks (b) during the intervention.
See this image and copyright information in PMC

References

    1. Van Dam RM, Hu FB. Coffee consumption and risk of type 2 diabetes: a systematic review. Journal of the American Medical Association. 2005;294(1):97–104. - PubMed
    1. Huxley R, Lee CMY, Barzi F, et al. Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis. Archives of Internal Medicine. 2009;169(22):2053–2063. - PubMed
    1. Salazar-Martinez E, Willett WC, Ascherio A, et al. Coffee consumption and risk for type 2 diabetes mellitus. Annals of Internal Medicine. 2004;140(1):1–8. - PubMed
    1. Van Dam RM, Willett WC, Manson JE, Hu FB. Coffee, caffeine, and risk of type 2 diabetes: a prospective cohort study in younger and middle-aged U.S. women. Diabetes Care. 2006;29(2):398–403. - PubMed
    1. Pereira MA, Parker ED, Folsom AR. Coffee consumption and risk of type 2 diabetes mellitus: an 11-year prospective study of 28 812 postmenopausal women. Archives of Internal Medicine. 2006;166(12):1311–1316. - PubMed

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