A study published Wednesday in the Journal of the American Heart Association found that caffeinated energy drinks altered the heart’s electrical activity and raised blood pressure.
The extent of these electrical changes — which signal the heart’s chambers squeezing and relaxing — is “generally considered mild,” according to study author Sachin Shah, a professor of pharmacy at the Thomas J. Long School of Pharmacy and Health Sciences at the University of the Pacific. However, people who take certain medications or have a specific type of heart condition could be at increased risk of a fatal arrhythmia, or irregular heartbeat, he added.
“Unlike drugs, supplements and consumer products do not necessarily get tested for safety,” Shah said in an email.
The American Beverage Association stands by the safety of energy drinks, indicating that many of their ingredients are also found in common foods and have been rigorously studied for safety.
But health experts like the World Health Organization say they “may pose danger to public health.” Children “should not consume” them, cautions the American Academy of Pediatrics.
Still, the global energy drink market continues to grow. It was worth $39 billion in 2013 and is forecast to reach $61 billion by 2021. So what exactly is inside these drinks, and how do they impact your body?
‘A black box’
Over the years, concerned experts have been getting closer to answering those questions, said Dr. John Higgins, a sports cardiologist with McGovern Medical School at the University of Texas Health Science Center in Houston.
Most energy drinks typically contain large amounts of caffeine; added sugars; vitamins, such as B vitamins; and legal stimulants, such as guarana, a plant that grows in the Amazon; taurine, an amino acid that’s naturally found in meat and fish; and L-carnitine, a substance in our bodies that helps turn fat into energy.
“Overall, the concern is that these vitamins, amino acids and herbals are often in higher concentrations than naturally in food or plants, and the effects when combined especially with caffeine may be enhanced,” Katherine Zeratsky, a clinical dietitian at the Mayo Clinic in Rochester, Minnesota, previously told CNN.
Higgins, who has led multiple studies on energy drinks and health impacts, agreed.
With the caffeine, sugar and stimulants, Higgins previously told CNN that more research is needed to determine how those ingredients could interact to cause negative health effects.
“They’re sort of a black box. We really don’t know a lot about them,” Higgins said of energy drinks.
“People need to be aware of that,” he said. “For certain groups, it could be potentially dangerous, like for those under 18, women who are pregnant, people who have a caffeine sensitivity, people who don’t consume caffeine on a regular basis and people who are taking certain medications, like Adderall for attention deficit (disorder).”