Energy Drink Side Effects May Affect Heart Rhythms: Study

New research suggests that side effects of energy drinks, such as Monster, Red Bull and Rockstar, could interfere with the electrical operation of the heart for some people, potentially increasing the risk of death. 

The findings were presented last week at a meeting of the American Heart Association, but the study has not yet been published in a medical journal.

In the study, researchers looked at seven different studies involving the highly caffeinated energy drinks, determining that an important measure of heart electrical activity, the QT interval, was prolonged among people who had recently consumed energy drinks.

According to the researchers, the prolonged QT interval they discovered in connection with energy drinks would have lead to an FDA warning if the beverages were a drug.

Energy drinks have become increasingly popular in recent years, especially among children and young adults who typically consume large amounts of the beverages, which contain high quantities of caffeine and other stimulants designed to give users a burst of energy. However, concerns have emerged about the potential health risks associated with energy drinks, and many of the products do not even have to list their ingredients or caffeine levels because they are regulated as dietary supplement.

Research has found that caffeine overdose can result in heart attacks, cardiac arrhythmias and death after doses ranging from 200 to 400 milligrams, and many brands contain that much in each can. However, the scientists in the latests study say they are not certain what ingredient in energy drinks may be causing the prolonged QT intervals, which can lead to death in extreme cases.

Under increasing media and regulatory scrutiny, the makers of Monster Energy recently decided to stop classifying their product as dietary supplement and joined the American Beverage Association, which means its labels will soon carry nutritional information that includes the amount of caffeine. The FDA has received at least 37 adverse event reports involving Monster drinks since 2004, including at least five deaths reported over the past year and a sixth reported in 2009.

In October, a Monster Energy wrongful death lawsuit was filed by the family of a 14 year old girl who died from a cardiac arrest that was allegedly caused by a caffeine overdose after consuming two 24 ounce cans within a 24 hour period.