Though drinking more than two energy drinks per day increases heart risks, adding alcohol slows down the breakdown of the caffeine, adding further dangers.
According to the Centers for Disease Control and Prevention (CDC), 31% of 12-17-year-olds regularly consume energy drinks and 34% of 18-24-year-olds reach for the stimulant-infused drinks on a regular basis.
"Energy drinks have become enormously popular in the past decade and half are consumed extensively by people who wish to reduce fatigue, increase wakefulness, and improve concentration and performance," says Dr. Ian Musgrave, from the University of Adelaide's Discipline of Pharmacology in Australia.
His colleagues from the university publish their results in the International Journal of Cardiology.
Though caffeine is typically present in energy drinks, they can also contain plant-based stimulants, simple sugars and other additives.
Medical News Today previously examined how energy drinks affect our bodies within 24 hours. Most revelatory was the finding that it takes an average of 12 hours for our bodies to completely remove the caffeine from the bloodstream that energy drinks provide.
High consumers of energy drinks had more adverse heart reactions
To investigate and observe how energy drinks affect patients presenting to a hospital, the researchers surveyed patients who were attending a hospital emergency department in South Australia between 2014-2015 and who presented with heart palpitations.
According to the team, 70% of them had previously consumed some type of energy drink in their lifetime.
However, the study found a more direct link; of the patients surveyed, 36% had ingested at least one energy drink in the 24 hours before going to the hospital.
Of these patients, eight had consumed more than five energy drinks, and one had consumed 12 energy drinks along with alcohol.
Furthermore, the patients who heavily consumed energy drinks had a significantly higher occurrence of heart palpitations, compared with those who drank less than one drink per day.
The researchers add that "fast heartbeat, heart palpitations and chest pain was seen in energy drink consumers who were healthy and had no risk factors for heart disease."
Adding alcohol increases danger
Dr. Musgrave says there has been increasing concern that caffeinated alcoholic beverages (CABs) are harmful.
In November 2010, the Food and Drug Administration (FDA) instructed seven manufacturers of CABs that their drinks had to be pulled from the market, adding that the "FDA does not find support for the claim that the addition of caffeine to these alcoholic beverages is 'generally recognized as safe,' which is the legal standard."
Dr. Musgrave adds:
"One of the problems with alcohol is that not only does it reduce your ability to make sensible decisions about energy drinks, it actually slows the breakdown of caffeine in energy drinks and therefore is likely to increase the concentration to levels which may be dangerous."
He says that although caffeine is one of the safest stimulants, caffeinated beverages seem to be more problematic for individuals who are predisposed to heart conditions.
"People are unlikely to slam down seven espressos one after the other," he says, "but people are more likely to - especially under the influence - misuse energy drinks in that way."
According to Dr. Musgrave, the study shines a light on the need for better education about the dangers of consuming more than the recommended maximum amount of energy drinks per day, which is two.
"Anyone feeling unwell after consuming energy drinks should seek medical advice," he concludes.
MNT previously reported on a study published in JAMA that suggested a single energy drink could raise cardiovascular risk for young adults.