A new study conducted by researchers at the Duke University Medical Center has suggested that eliminating caffeine from the diet might help in controlling diabetes.
The researchers said that daily consumption of caffeine in coffee, tea or soft drinks raises blood sugar levels for people with Type 2 diabetes and might undermine efforts to control their disease.
For the study, new technology that measured participants' glucose (sugar) levels on a constant basis throughout the day was used.
The findings of the study contribute to a growing body of research suggesting that cutting caffeine might be a good way to manage blood sugar levels.
Dr. James Lane, a psychologist at Duke and the lead author, 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 participant had a tiny glucose monitor embedded under their abdominal skin that continuously monitored their glucose levels over a 72-hour period.
The researchers gave participants capsules containing caffeine equal to about four cups of coffee on one day and then identical capsules that contained a placebo on another day.
Every participant had the same nutrition drink for breakfast, but was free to eat whatever they liked for lunch and dinner.
It was found that when the participants consumed caffeine, their average daily sugar levels went up 8 per cent.
Caffeine also inflated 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," Lane said.
"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 - the 'fight or flight" hormone that we know can also boost sugar levels," Lane added.
Lane said that there are no current guidelines suggesting diabetics shouldn't drink coffee, but that day may come, if further studies bear out their findings.
"Our study suggests that one way to lower blood sugar is to simply quit drinking coffee, or any other caffeinated beverages. It may not be easy, but it doesn't cost a dime, and there are no side effects," Lane said.
The study is published in the February issue of Diabetes Care.
