Caffeine-laden “energy shots” appear to trigger short-term insulin resistance in teenagers, Canadian researchers report.
The finding suggests that this effect might lay the foundation for developing type 2 diabetes later in life, the researchers said.
Teens who downed a tiny orange bottle of 5-hour Energy — which contains no sugar but has 208 milligrams of caffeine — were not able to metabolize sugar as efficiently as when they drank a decaf version of the same drink, the study found.
Those who drank traditional 5-hour Energy experienced a 25 percent increase in both their blood sugar and blood insulin levels compared to when they drank the decaf version, the study authors said.
“It’s the caffeine,” said senior researcher Jane Shearer, an assistant professor and diabetes researcher at the University of Calgary in Canada. “The elevated caffeine content in energy drinks is what causes this response.”
The findings were to be reported Wednesday at the World Diabetes Congress, in Vancouver, Canada. Research presented at meetings is considered preliminary until published in a peer-reviewed medical journal.
According to Dr. Jan Hux, chief science officer for the Canadian Diabetes Association, the results are troubling because the teens’ blood sugar levels did not decrease even after their bodies started producing insulin, the hormone that manages blood sugar.
“You think if the insulin is high, the sugar should go down,” Hux said. “That suggests that the caffeine is causing insulin resistance. The body has to make more insulin to achieve the same effect.”
Insulin resistance is the first step in developing type 2 diabetes, Hux explained.
For the study, 20 teenagers between the ages of 13 and 19 were randomly given either a traditional 5-hour Energy shot or a shot of 5-hour Energy Decaf. Forty minutes later, they all were given a standard oral glucose tolerance test.
The glucose tolerance test measures the body’s ability to process sugar, and is a standard screening tool for type 2 diabetes, Hux said. Participants ingest a large dose of sugar, and then researchers take regular blood samples to see how blood sugar and insulin levels respond.
All the teens eventually tried both 5-hour Energy products, so their blood sugar and insulin response could be compared head-to-head between the caffeinated and non-caffeinated versions.
When the teens drank caffeinated 5-hour Energy, they experienced a 24.6 percent greater increase in blood glucose levels and a 26.4 percent greater increase in insulin levels during the glucose tolerance test than when they drank decaf 5-hour Energy, the researchers reported.