Energy drinks' side effects can include a disturbed heart rhythm and higher blood pressure, according to new research presented at an American Heart Association conference this week.
The link between energy drink consumption and heart irregularities is well established - a teenage girl died of cardiac arrest after drinking Monster energy drink last fall, and the Food and Drug Administration linked 5-Hour Energy to 13 deaths since 2008, mostly from heart attacks. More than 20,000 people were taken to emergency rooms for problems related to energy drinks' side effects.
Researchers led by Dr. Sachin A. Shah of the University of the Pacific in Stockton, California, conducted a meta-analysis of data from seven previously published studies to determine whether consuming energy drinks had side effects related to heart health. The participants in those studies included healthy, young patients who were 18-45 years old.
The results were presented at the Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions in New Orleans on Thursday afternoon, March 21.
The first part of their analysis focused on the QT interval, a measure of the heart's rhythm on an electrocardiogram. A prolonged QT interval is associated with life-threatening arrhythmias- people can suffer irregular heartbeats or sudden death from heart failure.
The researchers analyzed that measure in 93 people who had just consumed one to three cans of energy drinks. They found that in people who drank the energy drinks, the interval was 10 milliseconds longer than in people who did not drink them.
"Doctors are generally concerned if patients experience an additional 30 milliseconds in their QT interval from baseline," said Shah. The findings suggest that energy drinks' side effects could include prolonging the QT interval, which could cause heart failure.
The results also showed that the systolic blood pressure, the higher number in a blood pressure reading, increased an average of 3.5 points in a sample of 132 participants who consumed energy drinks.
"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." Shah said. "Patients with high blood pressures or long QT syndrome should use caution and judgment before consuming an energy drink.
Shah also cautioned that people who do not normally drink caffeine may have a more extreme increase in blood pressure from consuming energy drinks, which can have higher caffeine concentrations than a cup of coffee.
The conference presentation contradicts a recent study which found that energy drinks containing caffeine and taurine may actually boost heart function in healthy people. That study found no increase in systolic blood pressure.
The study authors reminded conference attendees that the sample showed heart irregularities in healthy young patients who consumed energy drinks. People with health concerns, or are older, may be at a higher risk for energy drinks' side effects on their heart rhythms and blood pressure.
Published by Medicaldaily.com