Adverse effects of caffeinated energy drinks among youth and young adults in Canada: a Web-based survey

CMAJ Open. 2018 Jan 9;6(1):E19-E25. doi: 10.9778/cmajo.20160154.


Background: Energy drink consumption has increased dramatically among young Canadians, with anecdotal evidence of adverse health effects. There is a lack of population-based studies to examine the prevalence of adverse events from energy drinks, particularly among young people. The current study sought to assess adverse events from energy drinks among a population-based sample of youth and young adults in Canada.

Methods: An online survey was conducted in 2015 with a national sample of youth (aged 12-17 yr) and young adults (aged 18-24 yr) recruited from a consumer panel. Respondents reported prior consumption of energy drinks as well as adverse outcomes, concurrent activities associated with the outcomes and whether medical attention was sought or considered. Adverse events from coffee were also assessed for comparison. Weighted analyses are reported.

Results: Of the 2055 respondents, 1516 (73.8%) reported having ever consumed an energy drink, and 1741 (84.7%) reported having ever consumed coffee (unweighted). Overall, 55.4% of respondents who had ever consumed an energy drink reported that they had experienced at least 1 adverse event, including fast heartbeat (24.7%), difficulty sleeping (24.1%), headache (18.3%), nausea/vomiting/diarrhea (5.1%), chest pain (3.6%) and seizures (0.2%); 3.1% had sought or had considered seeking medical help for an adverse event. The prevalence of reported adverse events was significantly greater among energy drink consumers than among coffee consumers (36.0%) (odds ratio [OR] 2.67 [95% confidence interval (CI) 2.01-2.56]), as was the proportion who reported seeking or considering seeking medical help for adverse events (3.1% v. 1.4%) (OR 2.18 [95% CI 1.39-3.41]).

Interpretation: More than half of youth and young adults who had consumed energy drinks reported adverse outcomes, some serious enough to warrant seeking medical help. The adverse outcomes were consistent with the physiologic effects of caffeine but were significantly more prevalent than with other sources of caffeine such as coffee, consistent with data from national adverse event databases.