Does caffeine affect blood sugar?

For most healthy adults, caffeine doesn't noticeably affect blood sugar. The medical term for blood sugar is glucose. Having up to 400 milligrams of caffeine a day seems to be safe for most people.

In the U.S., one of the most common sources of caffeine is coffee. The average U.S. adult drinks about two 8-ounce (240-milliliter) cups of coffee a day. A cup of coffee generally has about 120 to 180 milligrams of caffeine. But the amount of caffeine can vary quite a bit depending on the type of coffee. Other sources of caffeine include energy drinks, some soft drinks, black tea and chocolate.

Some studies suggest that drinking coffee — whether caffeinated or decaffeinated — may actually reduce the risk of developing type 2 diabetes.

If you have diabetes, caffeine might affect the way your body uses insulin. And that could lead to higher or lower blood sugar. For some people with diabetes, about 200 milligrams of caffeine can cause this change. For others, it may have no significant effect on blood sugar.

Caffeine affects each person differently. If you have diabetes or if you find it hard to control your blood sugar, limiting the amount of caffeine in your diet might be helpful. Talk to a member of your healthcare team if you have questions or concerns about caffeine.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

We use the data you provide to deliver you the content you requested. To provide you with the most relevant and helpful information, we may combine your email and website data with other information we have about you. If you are a Mayo Clinic patient, we will only use your protected health information as outlined in our Notice of Privacy Practices. You may opt out of email communications at any time by clicking on the unsubscribe link in the email.

March 07, 2024 See more Expert Answers

See also

  1. Health foods
  2. A1C test
  3. Acanthosis nigricans
  4. Amputation and diabetes
  5. Atkins Diet
  6. Bariatric surgery
  7. Can medicine help prevent diabetic macular edema?
  8. CBD safety
  9. Diabetes drugs and weight loss
  10. Diabetes foods: Can I substitute honey for sugar?
  11. Diabetes prevention: 5 tips for taking control
  12. Medications for type 2 diabetes
  13. Types of diabetic neuropathy
  14. Does keeping a proper blood sugar level prevent diabetic macular edema and other eye problems?
  15. Prickly pear cactus
  16. Endoscopic sleeve gastroplasty
  17. Endoscopic Sleeve Gastroplasty (Gastric Sleeve)
  18. Exercise and chronic disease
  19. Fasting diet: Can it improve my heart health?
  20. Fatigue
  21. Frequent urination
  22. Gastric bypass (Roux-en-Y)
  23. Gastric Bypass Complications
  24. Gastric bypass diet
  25. Gastric Bypass Surgery: One Patient's Journey
  26. Glucose tolerance test
  27. Weight-loss surgery
  28. Hyperinsulinemia: Is it diabetes?
  29. What is insulin resistance? A Mayo Clinic expert explains
  30. Intermittent fasting
  31. Kidney disease FAQs
  32. Living with diabetic macular edema
  33. Low-glycemic index diet
  34. Reducing your risks of diabetic macular edema
  35. Screening for diabetic macular edema: How often?
  36. Spotting symptoms of diabetic macular edema
  37. Symptom Checker
  38. Type 2 diabetes
  39. Unexplained weight loss
  40. Biliopancreatic diversion with duodenal switch
  41. Weight Loss Surgery Options
  42. What is diabetic macular edema?
  43. Mayo Clinic Minute: Out of shape kids and diabetes