• image.alt
  • With Mayo Clinic endocrinologist

    Maria Collazo-Clavell, M.D.

    read biography

Free

E-newsletter

Subscribe to Housecall

Our weekly general interest
e-newsletter keeps you up to date on a wide variety of health topics.

Sign up now

Question

Caffeine: Does it affect blood sugar?

Does caffeine affect blood sugar?

Answer

Controlling Your Diabetes

Subscribe to our Controlling Your Diabetes e-newsletter to stay up to date on diabetes topics.

Sign up now
from Maria Collazo-Clavell, M.D.

Caffeine impairs insulin action, but doesn't necessarily affect blood sugar (glucose) levels in young, healthy adults. However, if you have type 2 diabetes, the impact of caffeine on insulin action may be associated with a small, but detectable rise in blood sugar levels, particularly after meals. About 250 milligrams of caffeine — or the equivalent of 2 to 2 1/2 cups (473 to 591 milliliters) of plain, brewed coffee — a day may cause this effect.

If you have type 2 diabetes and you're struggling to control your blood sugar levels, limiting the amount of caffeine in your diet may provide a benefit.

Next question
Glucosamine: Does it affect blood sugar?
References
  1. MacKenzie T, et al. Metabolic and hormonal effects of caffeine: Randomized, double-blind, placebo-controlled crossover trial. Metabolism. 2007;56:1694.
  2. Lane JD, et al. Exaggeration of postprandial hyperglycemia in patients with type 2 diabetes by administration of caffeine in coffee. Endocrine Practice. 2007;13:239.
  3. Tunnicliffe JM, et al. Coffee, glucose homeostasis, and insulin resistance: Physiological mechanisms and mediators. Applied Physiology, Nutrition and Metabolism. 2008;33:1290.
  4. USDA National Nutrient Database for Standard Reference, Release 24. U.S. Department of Agriculture. http://ndb.nal.usda.gov/. Accessed Jan. 31, 2012.
  5. Moisey LL, et al. Caffeinated coffee consumption impairs blood glucose homeostasis in response to high and low glycemic index meals in healthy men. American Journal of Clinical Nutrition. 2008;87:1254
  6. Greenberg JA, et al. Decaffeinated coffee and glucose metabolism in young men. Diabetes Care. 2010;33:278
AN01804 April 4, 2012

© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

  • Reprints
  • Print
  • Share on:

  • Email

Advertisement


Text Size: smaller largerlarger