Objective: To describe benefits and adverse effects associated with the consumption of energy drinks.
Data sources: Searches were conducted using Medline, IPA (International Pharmaceutical Abstracts), EMBASE, and MANTIS; databases such as Natural Medicines Comprehensive Database, Natural Standard, ALTMEDEX, and AltHealthWatch; and Google (range 1980 to September 2007). Search terms included energy drink, Red Bull, caffeine, glucose, ginseng, guarana, taurine, and bitter orange.
Data synthesis: Most energy drinks contain natural products such as guarana, ginseng, and taurine. As much as 80 to 300 mg of caffeine and 35 grams of processed sugar per 8-ounce serving are commonly present in energy drinks such as Cocaine, Pimp Juice, Red Bull, and Spike Shooter. No reports were identified of negative effects associated with taurine, ginseng, and guarana used in the amounts found in most energy drinks. Commonly reported adverse effects seen with caffeine in the quantities present in most energy drinks are insomnia, nervousness, headache, and tachycardia. Four documented case reports of caffeine-associated deaths were found, as well as four separate cases of seizures associated with the consumption of energy drinks.
Conclusion: The amounts of guarana, taurine, and ginseng found in popular energy drinks are far below the amounts expected to deliver either therapeutic benefits or adverse events. However, caffeine and sugar are present in amounts known to cause a variety of adverse health effects.