Energy drinks often contain caffeine or sugar, which can boost energy temporarily by affecting neurotransmitters. These brain chemicals regulate your mood and behavior. Some manufacturers produce caffeine-free and sugar-free energy drinks. The drinks usually contain vitamins and herbs that may provide vigor. Ginseng, used in some energy drinks, may have stimulating effects. Athletes use energy drinks for a boost during sports performances. Drinking excessive amounts of energy drinks could have adverse effects, especially if they contain caffeine.
Sugar and Carbohydrates
The sugar and carbohydrates in energy drinks may be enough to improve an athlete’s performance, according to researchers reporting in the April 2009 issue of the “Journal of Physiology.” The researchers gave athletes drinks either containing glucose, a sugar, the carbohydrate maltodextrin, sometimes used in energy drinks, or neither of the substances. The drinks were flavored with artificial sweeteners. The athletes rinsed their mouths with the watery drinks during a challenging time trial. Athletes taking the sugary or maltodextrin drinks outperformed those taking the drinks that only contained water and artificial sweetener.
Researchers who conducted the study also discovered through imaging techniques that the sugar and carbohydrates stimulated areas of the brain that provide reward and pleasure, whereas the artificial sweetener did not. Complex carbohydrates and simple carbohydrates, such as sugar, activate the neurotransmitter serotonin to provide relaxation. The researchers concluded that the athletes had a reduced perception of the workload from the sugar and carbohydrates. This helped improve their motor skills for muscle-related activities.
Caffeine also stimulates the central nervous system to increase alertness, but excessive amounts can cause headaches, nervousness, dizziness and insomnia. Caffeine travels from the bloodstream to the brain, where it interferes with the chemical adenosine, which is involved in energy formation. Energy levels drop as caffeine leaves your system. Caffeine becomes a problem if withdrawal symptoms set in to produce dependence. It causes a cycle of getting enough caffeine in your system to stay energized.
The caffeine content in energy drinks varies. Many drinks do not list caffeine on the label, and the FDA does not regulate many drinks promoted as health supplements. Researchers at Johns Hopkins University say some energy drinks contain the equivalent of 14 cans of cola, which causes potential risks of caffeine intoxication. Aside from dependence, nervousness, anxiety and insomnia, overdosing on caffeine can lead to tremors, rapid heartbeats and even death in rare cases. Consumers need to be aware of potential health hazards of excess consumption of energy drinks with caffeine, the researchers report in the January 2009 issue of “Drug and Alcohol Dependence.”
- ScienceDaily: Energy Drinks Work -- In Mysterious Ways; April 2009
- “Journal of Physiology;” Carbohydrate Sensing in the Human Mouth: Effects on Exercise Performance and Brain Activity; Chambers, Bride, Jones; April 2009
- Neuroscience for Kids: Caffeine
- Medical News Today: Caffeinated Energy Drinks Should Have Better Labels; September 2008
- “Drug and Alcohol Dependence;” Caffeinated Energy Drinks--A Growing Problem; Reissig CJ, Strain EC, Griffiths RR; January 2009