According to Packaged Facts market research, the market for energy drinks in 2006 was over $5.4 billion. Another study by the Simmons Market Research Bureau found that 62 percent of people between 18 to 24 years of age had used an energy drink during 2005. While sports drinks are intended to supply needed electrolytes and facilitate hydration, the increasingly popular energy drinks are designed only to give a temporary energy boost. Using these drinks to supply energy for exercise may have negative health effects.
Negative Effects on Hydration
Energy drinks rely heavily on caffeine and sugar for the energy boost they provide. The high levels of sugar in these drinks can actually slow down your body’s ability to absorb needed fluids; when used in conjunction with exercise, they may cause dehydration and gastrointestinal distress. Manufacturers of energy drinks are quick to point out that their products are not intended for fluid replacement. However, little is said about their potential negative effect on hydration.
Along with sugar, caffeine is the other main source of the energy drink’s kick. The label may list the caffeine content directly, or it may be hidden in other ingredients that contain caffeine, such as guarana or yerba met. Some energy drinks contains roughly the same amount of caffeine per serving as one to three cups of coffee. The equivalent of three cups of coffee may seem harmless, but a study published in the January 17, 2006 issue of the "Journal of the American College of Cardiology" shows that the caffeine contained in just two cups of coffee inhibits the body’s ability to boost blood flow to the heart during exercise.
Additionally, the amount of caffeine varies from drink to drink. Some contain as much as 500 mg. According to Dr. Roland Griffiths of Johns Hopkins School of Medicine, that could cause caffeine intoxication for a person not accustomed to caffeine. Caffeine intoxication produces anxiety, insomnia, nausea, vomiting, tremors and rapid heart rate.
A typical energy drink may contain as much as 8,000 percent of the recommended daily amount of certain B vitamins. Habitual high doses of vitamin B6 may cause nerve damage and can lead to B12 deficiency.
The long-term effects of large doses of other common energy drink ingredients on the body during exercise are untested and unknown. Ingredients like taurene, gingko biloba and ginseng have not been extensively tested.
The directions and warnings on energy drink labels may be scary reading. In spite of the increasing use of these drinks, they are not regulated by the FDA. A letter written by Dr. Griffiths and signed by 100 physicians and scientists was sent to the FDA in 2008 asking that there be a limit placed on the amount of stimulants they can contain. It also asked that the manufacturer be required to list the caffeine content as well as a warning label. It is the policy of the FDA not to comment on petitions.