Read the current Defeat Diabetes® E-Lerts™ Newsletter

This website is certified by Health On the Net Foundation. Click to verify.
This site complies with the HONcode standard for trustworthy health information:
verify here.

Defeat Diabetes
150 153rd Ave,
Suite 300

Madeira Beach, FL 33708

Caffeine Boosts Blood Sugar Among Patients with Diabetes

Posted: Thursday, February 07, 2008

Caffeine in even moderate doses may impair glucose control in type 2 diabetes, researchers report. Consuming equivalent of 4 cups a day led to spikes in blood sugar levels of 8%. 

James D. Lane, Ph.D., of Duke reported that In a small study, blood glucose levels were 8% higher on average when patients had the caffeine equivalent of four cups of coffee a day. The effect was most noticeable after meals, with a 9% increase in glucose levels after breakfast, 15% after lunch, and 26% after dinner.

If patients are regular coffee drinkers, one thing they should consider even at this early point is trying to cut caffeine out of their diet to see if it helps them control their blood sugar better," Dr. Lane said. "It's worth a try."

The findings follow on the heels of a report that moderate caffeine intake doubles the risk of miscarriage among pregnant women and reinforce that caffeine can have negative consequences in special populations, he said.

"Caffeine is so widely consumed in our society," Dr. Lane said, "that we tend to forget or ignore the fact that it is a drug that does have widespread effects in the body." As a follow-up to their prior laboratory-based studies, the researchers conducted a double-blind crossover study using continuous glucose monitors to see the effects of caffeine among ambulatory patients as they went about their everyday lives.

The study included 10 patients with type 2 diabetes who managed their disease with diet, exercise, and oral agents, but not insulin therapy (mean glycosylated hemoglobin A1c 6.4%). They typically drank at least two cups of coffee a day, for a mean daily caffeine intake of 520 mg. After being fitted with the glucose monitors, participants were given caffeine pills on one day, for a total of 500 mg divided between breakfast and lunch, and placebo pills on the other day.
Participants had the same shake nutrition drink for breakfast both days, but chose their own lunch and dinner. They were to consume no other caffeine during the study.

Caffeine increased glucose levels averaged from 6 a.m. to 10 p.m. compared with placebo (8.0 versus 7.4 mmol/L, P<0.0001).

The same was true for postprandial glucose levels. Caffeine was associated with higher glucose concentrations in the three hours following breakfast (156mg/dL vs 144mg.dL)(8.7 versus 8.0 mmol/L), lunch 140mg/dL vs 122mg/dL)(7.8 versus 6.8 mmol/L), and dinner (155mg/dL vs 122mg/dL)(8.6 versus 6.8 mmol/L) compared with placebo (all P<0.0001). Furthermore, a similar rise in glucose would be likely whenever type 2 diabetic patients consume caffeine, the researchers said.

Ambulatory monitoring made the findings generalizable, Dr. Lane said. The effect was seen even among patients who typically drank coffee and had "sufficient opportunity to develop tolerance to the drug," the investigators noted.
Dr. Lane said his group suspects the effect would be large enough to have an impact upon glucose control, but "it's hard to find something with which to compare it," he said.

To determine the effect on treatment, the next step would be a study in which patients quit drinking coffee to see whether glucose control improves, he said.

Caffeine has at least two effects on the body that could impair glucose metabolism in type 2 diabetic patients, he said. Animal and some human studies have shown that caffeine impairs transport of glucose out of the bloodstream into the cell.
"But we are favoring the idea that caffeine is actually stimulating the liver to continue to produce and release glucose even after a meal when it's not needed because caffeine stimulates the release of adrenaline," he said. However, the data dosen’t necessarily mean that people with diabetes or at risk for it should stop drinking coffee. Several large observational studies have shown that coffee drinkers have a lower risk for diabetes. Researchers speculate that other compounds in the coffee have a beneficial effect and may blunt some of the negatives of caffeine.

Practice Pearl: Explain to interested patients that the study suggested even modest caffeine intake may work against their efforts to control diabetes.

Source: Diabetes In Control: Lane JD, et al "Caffeine increases ambulatory glucose and postprandial responses in coffee drinkers with type 2 diabetes" Diabetes Care 2008; 31: DOI: 10.2337/dc07-1112.

Join us on Facebook

Send your unopened, unexpired diabetes testing supplies to:

Defeat Diabetes Foundation
150 153rd Ave, Suite 300
Madeira Beach, FL 33708


DDF advertisement

 Friendly Banner

Friendly Banner
Analyze nutrition content by portion
DDF advertisement