Researchers used new technology that measured participants’ glucose levels on a constant basis throughout the day. Dr. James Lane, a psychologist at Duke and the lead author of the study, says it represents the first time researchers have been able to track the impact of caffeine consumption as patients got about their normal, everyday lives.
Lane studied 10 patients with established type 2 diabetes and who drank at least two cups of coffee every day and who were trying to manage their disease through diet, exercise and oral medications, but no extra insulin. Each had a tiny glucose monitor embedded under their abdominal skin that continuously monitored their glucose levels over a 72-hour period.
Participants took capsules containing caffeine equal to about four cups of coffee on one day and then identical capsules that contained a placebo on another day. Everyone had the same nutrition drink for breakfast, but were free to eat whatever they liked for lunch and dinner.
The researchers found that when the participants consumed caffeine, their average daily sugar levels went up 8 per cent. Caffeine also exaggerated the rise in glucose after meals: increasing by 9 percent after breakfast, 15 percent after lunch and 26 per cent after dinner.
“We’re not sure what it is about caffeine that drives glucose levels up, but we have a couple of theories,” says Lane. “It could be that caffeine interferes with the process that moves glucose from the blood and into muscle and other cells in the body where it is used for fuel. It may also be that caffeine triggers the release of adrenaline that can also boost sugar levels.”
There are no current guidelines suggesting diabetics shouldn’t drink coffee, but Lane says that day may come, if further studies bear out their findings.
MEDICA.de; Source: Duke University Medical Center