As people continue to quaff high levels of caffeine-filled energy drinks, experts are looking at what the effect might be.

A new study has found that drinking more than two energy drinks per day is associated with adverse heart reactions, including a fast heartbeat, heart palpitations and chest pain.

The University of Adelaide has completed a survey of patients aged 13 to 40 who presented with heart palpitations at an emergency department in South Australia.

The researchers found 36 per cent had consumed at least one energy drink in the 24 hours prior to presenting at the hospital.

“Eight of these patients had consumed a large quantity (more than five drinks), with one patient having consumed 12 energy drinks with alcohol,” said co-author on the paper, Dr Scott Willoughby.

“Those patients who were heavy consumers of energy drinks were found to have a significantly higher frequency of heart palpitations than those who consumed less than one per day.

“And, importantly, fast heartbeat, heart palpitations and chest pain was seen in energy drink consumers who were healthy and had no risk factors for heart disease,” he said.

Dr Ian Musgrave, from the University of Adelaide’s Discipline of Pharmacology, said the findings increased concern that the consumption of energy drinks may lead to harm.

“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,” Dr Musgrave said.

“In line with the growing popularity and consumption of these drinks, there has been increasing concern among health practitioners and researchers.

“The major stimulant in these drinks is caffeine, which is generally safe when consumed at the recommended levels. However, some people appear to be more sensitive to the effects of caffeine, and the combination of ingredients in these energy drinks may pose a further threat to those who consume large quantities.

“Different brands of energy drinks contain different ingredients, but most of them combine high levels of caffeine with large quantities of sugar as well as vitamins and herbal extracts.

“When vitamins and herbal extracts are combined together, they can create a toxic combination. Furthermore, the drinks are even more harmful when consumed with alcohol.

“Anyone feeling unwell after consuming energy drinks should seek medical advice,” he says.

Researchers say it is not yet clear exactly which ingredients in energy drinks lead to adverse heart reactions.