Plenty of controversy surrounds energy drinks – the amount of caffeine they contain and their popularity among young people, in particular. But according to a new study from researchers at the University of Calgary, caffeinated energy drinks may also cause blood insulin levels to spike, which could ultimately make it harder for the body to regulate blood sugar levels.
The research, led by Dr. Jane Shearer, associate professor in the faculty of kinesiology at the University of Calgary, was presented this week at the World Diabetes Congress in Vancouver. To test the effects of energy drinks, she and colleagues recruited 20 teenagers and had them consume either a caffeinated or a decaffeinated 5-hour Energy shot. (The company did not respond to a request for comment.) All of the drinks were sugar-free. Then, they performed an oral glucose test.
They found that consuming energy drinks with caffeine led to a 25-per-cent increase in blood glucose levels and a 26-per-cent spike in insulin levels. Because caffeine stays in the system for several hours after ingestion, this means glucose regulation can be disrupted for a long time after having an energy drink.
The reason to be concerned? Those high glucose and insulin levels are potential risk factors for serious diseases, including Type 2 diabetes and cardiovascular disease. “People say it’s kids, who cares? But cardiovascular disease doesn’t start when you’re 50 years old,” Shearer said. “The process starts in young adulthood.”
Critics have been complaining for years that energy-drink makers go out of their way to market their products to young people by sponsoring athletic events or online gaming championships. Shearer says she saw this first-hand over the past year, during which her eight-year-old daughter was given energy drinks in a line at Whistler and at the Calgary Stampede.
Jim Goetz, president of the Canadian Beverage Association, said it’s important to focus on total caffeine consumption, not just energy drinks, and that parents have a responsibility to keep it in check. He also pointed out that energy-drink makers follow industry guidelines that state they can’t market or advertise to children under age 12.
Those guidelines, however, are voluntary and there’s no systematic way to enforce them. Shearer is advocating for greater restrictions on advertising and more education to make kids aware of the potential risks of energy drinks.
Goetz noted that Shearer’s study focused on energy shots, which are regulated differently than energy drinks in Canada and aren’t represented by his industry association. Typically, energy shots can be consumed in a gulp and can contain up to 200 milligrams of caffeine. Health Canada says that single-serve energy drinks (500 millilitres or less) can’t exceed 180 mg of caffeine, more than the amount in a brewed cup of coffee (237 millilitres).
Children ages 10 to 12 shouldn’t exceed 85 mg of caffeine a day, Health Canada says.
A 2013 survey from Toronto’s Centre for Addiction and Mental Health found that 40 per cent of students from Grades 7 to 12 had consumed an energy drink at least once in the past year, including 26 per cent of Grade 7 students and 34 per cent of Grade 8 students. According to a Health Canada report, the department received 61 reports of adverse events linked to energy drinks. Of those, 32 were serious, including seven that occurred in adolescents.