Higher blood pressure, palpitations
One study, titled Energy drinks: Increasing evidence of negative cardiovascular effects, found that two or more cans of energy drinks in one day was “associated with higher diastolic blood pressure as well as increased frequency of palpitations, rising with co-ingestion of alcohol, even in healthy individuals without cardiovascular risk factors”.
In addition, this study found that these drinks could pose an even greater risk to health when they are mixed with other illicit drugs, including death.
Researchers said there have been a number of case reports that links energy drinks with myocardial ischemia, which occurs when blood to the heart is reduced. Consumption of the drink should be avoided by adolescents in order to avoid negative cardiovascular effects, they wrote.
“Although further research in larger randomized or prospective studies is warranted to establish an unequivocal link between EDs' intake and increased cardiovascular complications, clear guidelines for physicians would be welcome in order to educate and advertise the general population about the adverse cardiovascular effects of large EDs' consumption as well as to achieve responsible use,” researchers wrote in the report.
A separate study, titled A survey of energy drink consumption among young patients presenting to the emergency department with the symptom of palpitations, surveyed patients at a South Australian hospital between 2014 and 2015, 36% of which had ingested an energy drink within 24 hours of going to the hospital.
“Given the potential adverse effects of energy drink consumption we conducted a survey to determine the impact of these drinks on emergency department presentations in otherwise healthy young adults,” these researchers wrote.
Researchers in this study found that those who consumed more than one energy drink per day had a greater chance of experiencing heart palpitations.
In a 2014 survey by Canadean, six out of 10 consumers believed energy drink consumption was bad for their health and were concerned about the ingredients these drinks contained.
However, Mintel reported in 2015 that consumption was still common among millennials. Approximately 64% of millennials ages 27 to 27 consume energy drinks and 29% have consumed more than usual in the past three months.
There is now a growing body of energy drinks on the market which substitute caffeine and other ingredients for natural alternatives, such as green tea extract and vitamin B.