High energy drinks may be harmful for people with heart conditions

4th May 2017

People with underlying heart conditions, such as cardiomyopathy, might want to avoid high energy drinks until more is known about their impact on heart health.

That is the view of researchers in an article in the Journal of the American Heart Association.

The team, including doctor of pharmacy Emily Fletcher from the David Grant USAF Medical Centre, said that preliminary evidence from the study showed that the drinks may in the short term affect the heart’s QT interval, a measure of time in the organ’s electrical cycle.  A lengthened QT interval can lead to dangerous heart rhythms.

She said that the small study of military personnel showed that high-volume energy drink was linked to more heart and blood pressure changes compared with a control drink containing the same amount of caffeine.

Those in the energy drink arm had a significantly higher change in corrected QT interval compared with those in the caffeine arm after two hours.

"Based on this preliminary evidence in young, healthy adults, people who have high blood pressure, underlying cardiac conditions or other health issues might want to avoid or use caution when consuming energy drinks until more is known about their impact on heart health," the researchers wrote in the Journal of the American Heart Association. 

The group recruited 18 people (12 men) from 2013 to 2014 on a U.S. Air Force Base. All were randomised to receive 32oz of a commercially available energy drink or a control drink, both of which contained 320 mg of caffeine. After six days without, participants switched drinks.

The researchers collected ECG and blood pressure measurements before the drinks and at one, two, four, six, and 24 hours after drink consumption.

Changes in corrected QT intervals were different between the two groups after two hours, but not at other time points.

The researchers concluded that the findings "suggest that ingredients other than caffeine may have some blood pressure altering effects, but this needs further evaluation."