Scientists sound alarm over energy drink link to sudden cardiac arrest

Cardiac arrest victims studied by scientists had just had an energy drink when they became ill

Credit: REUTERS/Simon Dawson

Energy drinks have been linked to sudden cardiac arrest and may cause an abnormal heartbeat,a study has found.

Doctors warn that the drinks,which include high levels of caffeine as well as other accelerants such as taurine,may increase the risk of abnormal heart rhythms (arrhythmia).

They advise people with congenital heart conditions to limit consumption and for people to have the drinks in moderation.

Scientists looked at the cases of 144 people who had sudden cardiac arrests and found seven of them had consumed an energy drink shortly before the event which saw their heart stop beating.

The analysis from the Mayo clinic has not found a causal link between the drinks and heart conditions,but experts warn it “would be remiss to not sound the alarm”.

Scientists say it is possible the drinks could interfere with the electrical pathways that regulate heartbeat.

Dr Michael Ackerman,a genetic cardiologist at Mayo Clinic and study author,said that there “seemed to be a temporal link” between energy drinks and sudden cardiac arrests,but said there were other factors that could have been responsible for the health emergency,such as sleep deprivation,dehydration and extreme fasting.

“Unusual consumption of energy drinks most likely combined with other variables to create a ‘perfect storm’ of risk factors,leading to sudden cardiac arrest in these patients,” he said.

Six of the seven people who had a cardiac arrest after having an energy drink required electrical shock treatment to be revived and the other was manually resuscitated.

Three of the patients were regular energy drink consumers and four were revealed to have a type of genetic heart condition.

While the study,published in the Elsevier journal Heart Rhythm,did not prove a direct cause,the researchers still recommend consuming energy drinks in moderation.

‘Association by chance’

Dr Peter Schwartz,of the centre for cardiac arrhythmias of genetic origin and laboratory of cardiovascular genetics,in Milan,Italy,wrote in an accompanying editorial: “Critics might say of these findings,‘it’s just an association by chance’.

“We are perfectly aware that there is no clear and definitive evidence that energy drinks indeed cause life-threatening arrhythmias and that more data are necessary,but we would be remiss if we were not sounding the alarm.”

Energy drinks contain caffeine ranging from 80mg to 300mg per serving,compared with 100mg found in a cup of coffee.

Many of them also contain other additional ingredients,such as taurine and guarana,which are thought to alter heart rate,blood pressure and other heart functions.

Lead investigator Dr Ackerman added: “Although the relative risk is small and the absolute risk of sudden death after consuming an energy drink is even smaller,patients with a known sudden death predisposing genetic heart disease should weigh the risks and benefits of consuming such drinks in the balance.”