Energy drinks may overstimulate the heart after consumption, according to WebMD. Excessive consumption of energy drinks over a long period of time may lead to a permanent irregular heartbeat, in addition to other cardiovascular stress.
Mixing energy drinks with alcohol can also be dangerous. The stimulant effect of caffeinated drinks can lead a person to believe that she is not as impaired as she actually is. The addition of energy drinks to alcohol can be further dangerous when consuming a large quantity of alcoholic beverages, as both caffeine and alcohol dehydrate the body. This can cause a painful hangover or other medical problems.
Energy drinks are not necessarily bad for a healthy adult when consumed in moderation and not used as a mixer for alcohol. Energy drinks may produce negative side effects in children and teenagers when drunk in excessive amounts, or in adults that already have experienced heart problems.
Energy drinks may advertise health benefits, such as the addition of ginseng, vitamins or amino acids, such as taurine. However, these same additives are found in daily multivitamins and in many foods, without necessitating the consumption of energy drinks. The addition of these supplements does not make energy drinks healthier, according to Brown University.