There are many beverages containing stimulants that provide a jolt of energy, including black and green tea, coffee, soda and high-energy beverages containing guarana. However, it is important to carefully choose drinks with stimulants, as they may not only provide excess energy, but may also produce significant negative side effects soon after consumption.
Caffeine is the most consumed stimulant in the world. It is rare to meet anyone who does not ingest some form of caffeine daily, even if just in the morning to get going for the day, often through hot or cold beverages and chocolate. However, according to the Sloan-Kettering Cancer Center, caution should be used to avoid mixing caffeine products with guarana as they both contain the stimulant caffeine.
Guarana, also known as guarana gum, guarana seed, zoom cocoa and Brazilian cocoa, is a natural stimulant cultivated in Brazil from the Paullinia cupana Kunth shrub or tree. It is a member of the Sapindacae shrub family. Historically, according to FoodProcessing.com, the Tupi and Guarana tribes in Brazil have used the guarana plant for treating gastrointestinal complaints and to enhance the quality of life, as it is anecdotally believed to give those who consume it more strength and energy. However, claims of weight loss remain unproven.
According to FoodProcessing.com, “The big selling point of many guarana-containing products these days hinges on suggestions guarana may aid memory and slow down memory loss.” However, in a 2004 study published in the "Journal of Pharmacology, Biochemistry and Behavior," volunteers given guarana extract reported an increase in cognitive abilities, including attention span, memory speed and working memory.
According to the Mayo Clinic, consuming 2 to 4 cups of coffee--about 200 to 300 mg of caffeine--per day is OK; consuming 4 to 7 cups--500 to 600 mg per day of caffeine--is excessive and may even be harmful. The seeds of the guarana plant contain the highest percentage of caffeine in the guarana plant. For safety reasons, guarana is listed on the Food and Drug Administration's poisonous plant database.
Serious side effects of consuming too much guarana and/or caffeine include rapid or irregular heartbeat, elevated blood pressure and headache. Irritability and insomnia are also potential adverse effects of taking both guarana and caffeine, particularly when taken together, as the guarana may have an additive effect with caffeine.