The team at Duke University Medical Center in North
Carolina found a strong correlation between caffeine intake at
mealtime and increased glucose and insulin levels among people
with type 2 diabetes.
The American Diabetes Association says that at least 90
percent of the 17 million Americans diagnosed with diabetes
have type 2, in which the body either does not produce enough
insulin or cells ignore the insulin, which the body needs to
convert food into energy.
The findings are significant enough that the researchers
recommend people with diabetes consider reducing or eliminating
caffeine from their diets.
"In a healthy person, glucose is metabolized within an hour
or so after eating. Diabetics, however, do not metabolize
glucose as efficiently," said James Lane, a psychiatry
professor who led the study.
"It appears that diabetics who consume caffeine are likely
having a harder time regulating their insulin and glucose
levels than those who don't take caffeine."
Writing in the journal Diabetes Care, Lane and colleagues
said they studied 14 habitual coffee drinkers with type 2
diabetes.
The researchers put the volunteers on a controlled diet.
They took their medications, had their blood tested and
then were given caffeine capsules. More blood was taken then
and after giving the volunteers a liquid meal supplement.
Caffeine had little effect on glucose and insulin levels
when the volunteers fasted, the researchers found.
But after the liquid meal, those who were given caffeine
had a 21 percent increase in their glucose level and insulin
rose 48 percent.
"The goal of clinical treatment for diabetes is to keep the
person's blood glucose down," Lane said in a statement.
"It seems that caffeine, by further impairing the
metabolism of meals, is something diabetics ought to consider
avoiding. Some people already watch their diet and exercise
regularly. Avoiding caffeine might be another way to better
manage their disease. In fact, it's possible that staying away
from caffeine could provide bigger benefits altogether."
