The American Beverage Association (ABA) has hit out at a study that links energy drinks to heart attacks, saying most scientific evidence gives them a clean bill of health.

Research released yesterday (21 March) claimed that drinking one to three energy drinks may prolong the heart's QT interval, a segment of the heart’s rhythm on an electrocardiogram. Prolonging the QT interval can cause serious irregular heartbeats or sudden cardiac death, the study said.

“The correlation between energy drinks and increased systolic blood pressure is convincing and concerning, and more studies are needed to assess the impact on the heart rhythm,” said lead author Sachin Shah, from California's University of the Pacific. 

However, the ABA said today: “Most energy drinks contain about half the caffeine of a similarly-sized cup of coffeehouse coffee and the body of scientific evidence does not suggest that energy drinks cause adverse health outcomes.”

The study was an analysis of seven previously published studies and presented to the American Heart Association's Epidemiology and Prevention meeting in New Orleans.

This week a group of US doctors urged the Food and Drug Administration to limit caffeine content for energy drinks. It follows Canada's health regulators capping energy drinks at the start of the year at 180mg of caffeine for a single serve container.