The safety of energy drinks has been up for debate for years. A study published today in the Journal of the American Heart Association invites additional discussion about these popular beverages. Consumed by teens and adults alike, these beverages contain varying levels of caffeine, as well as blends of herbs, vitamins, and other stimulants.
The study, which included 18 healthy adults (ages 18-40), was conducted at a US Airforce Medical Center in California. The adults were divided into two groups. One group was given a 32 ounce serving of an energy drink (the researchers did not disclose the brand used). The others (the control group) was given a similar tasting beverage, a blend of carbonated water, cherry syrup, lime juice, and caffeine. Both groups consumed about 320 mg of caffeine (the equivalent of 3-4 cups of coffee). The energy drink, however, had an energy blend added, which contained B Vitamins, taurine and L-carnitine (both amino acids), ginseng, and guarana.
The electrical activity of the participants’ hearts was measured, as well as systolic blood pressure, immediately after consuming the drink, and then again five times later in a 24 hour period. What the research found is that two hours after guzzling the energy drink, participants had a temporary abnormality in the heart’s electrical activity. This could raise the risk of heart arrhythmia, which can be life-threatening. The control group showed no such changes.
Both groups had increased blood pressure (due to the caffeine). However, those in the energy drink group had elevated blood pressure for several hours longer than the control group. In fact, after six hours, the control group had returned to normal, while the energy drinkers still had higher blood pressures. The mechanism of why this happened is still unknown, but the author of the study hypothesizes that the added vitamins, minerals, and herbs prolonged the effect of caffeine in the body, or even caused the blood pressure increases independent of caffeine.
While researchers don’t fully understand how or why energy drinks harm health, they should be used cautiously. Children and adolescents should avoid them totally, as should pregnant women. Those with high blood pressure or other cardiac issues should steer clear as well. Caffeine is okay for the vast majority of people in moderate amounts, and there are far safer sources of caffeine available.