Adolescents saw their blood glucose and insulin levels spike after consuming caffeinated sugar-free energy drinks, researchers reported.
Twenty teens were given a bottle of 5-Hour Energy or 5-Hour Energy Decaf and 40 minutes later were given an oral glucose tolerance test. The blood glucose levels in both groups shot up, but the levels were higher for those who had the caffeinated drinks, who saw an area under the curve (AUC) increase of 24.6% (P=0.001) relative to the decaf version.
In addition, their insulin levels were raised higher than those with the decaf energy drink (AUC increase of 26.4%; P=0.037), according to , an MD candidate at the University of Calgary, who led the study. Virtanen reported the results at this year's meeting of the in Calgary, Canada.
Both drinks were sugar-free, so the effect the researchers saw was independent of sugar; both contain an of amino acids and malic acid . No caloric content is given on the products' labels. The caffeinated version contains the same amount of caffeine as in 12 ounces of coffee, according to the manufacturer's website.
Participants' mean body mass index was 22.6; 10 of the participants were female and 10 were male.
"It has been established that simultaneous ingestion of caffeine and a carbohydrate load impairs whole-body glucose disposal in adults," wrote Virtanen in an email to ֱ. "However, this is the first study (to our knowledge) examining the impact of caffeine-containing energy drinks on glucose levels and insulin response in adolescents, who are key consumers of these beverages."
Recent research has shown that energy drinks can have a negative effect on blood pressure and cardiometabolic health in adults.
"Continuous and prolonged insulin resistance associated with chronic caffeine-containing energy drink consumption in adolescents could contribute to increased metabolic risk in susceptible individuals later in life," concluded the authors.
"It is important to educate children, adolescents, and parents on the metabolic concerns associated with caffeine intake," wrote Virtanen. "The concern with these beverages is how readily available they are -- particularly the small-format energy 'shots' used in this study, which makes it easy to ingest a high dose of caffeine in one gulp, regardless of your body size."
Limitations of the study include small sample size.
Primary Source
International Diabetes Federation
Virtanen H, et al "Energy drink consumption impairs oral glucose tolerance in adolescents: a randomized, double-blind, crossover pilot study" IDF 2015; Poster number 0281-PD