Caffeine

Caffeine is a chemical that can be found in coffee, tea, cocoa, chocolate, soft drinks, and some medications.  Caffeine stimulates the central nervous system by increasing the metabolism inside neurons. It increases wakefulness by blocking the neurotransmitter, adenosine.

For most people, caffeine is harmless; however, in some people, it may affect sleep patterns, cause headaches, nervousness, dizziness, raise blood pressure, cause an uneven heart rhythm, dehydration, and even dependency.

In addition, mixing alcohol and energy drinks can be unhealthy because the caffeine in energy drinks can mask the depressant effects of alcohol. Studies have found that drinkers who consume alcohol mixed with energy drinks are three times more likely to binge drink than drinkers who do not mix alcohol with energy drinks, and and twice as likely to report:

• being taken advantage of sexually
• taking advantage of someone else sexually
• riding with a driver who was under the influence

Sources: Brain Power! The NIDA Junior Scientist Program, and The Centers for Disease Control and Prevention.