Limiting coffee intake could help people with type 2 diabetes better control their blood sugar levels, researchers report in the journal Diabetes Care. Researchers from the DukeUniversityMedicalCenter in Durham, North Carolina, examined how caffeine affects blood sugar levels in a small group of patients with diabetes. Using a tiny glucose monitor embedded under the abdominal skin, researchers monitored continuously the glucose levels of 10 people, with the average age of 63, throughout the study. Results showed that caffeine caused an increase in blood glucose levels throughout the day, especially after meals. It was further found that when participants were given four tablets containing caffeine equivalent to four cups of coffee, average glucose levels rose eight percent, compared to days when the same people were given four placebo tablets.
“Caffeine appears to disrupt glucose metabolism in a way that could be harmful to people with type 2 diabetes,” said lead study author James Lane, a medical psychologist at DukeUniversity. The new study disproves earlier researches on the relationship between caffeine and diabetes. Previous studies claimed that drinking coffee lowers the risk of type 2 diabetes. Caffeine, which can be found in coffee, tea, and many soft drinks, may raise blood sugar levels by triggering the release of the hormone adrenaline, which can raise blood sugar levels. It may also interfere with the process of glucose transportation from the blood into the muscle and other cells in the body to be burned as fuel. Researchers suggest that people with diabetes may want to avoid coffee and other beverages containing caffeine to keep their blood glucose level controlled.