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Caffeine’s Effect on the Body


Two high school students are up at 2:00 AM, cramming for a test. They don’t, however, feel tired. In fact they fell totally wired. Their hearts are racing, and although they’ve been cramming since 6:00 PM that day, none of the information seems to be sticking in their heads. They can’t concentrate, and they have a feeling that they couldn’t sleep, even if they tried. What are these kids on? Amphetamines? Cocaine? Here’s a hint: it’s perfectly legal.
Caffeine is a stimulant. It is the most popular drug in the world, and has many medical and non-medical uses. Caffeine enhances the activity of cells both at the surface of the cortex and in the deeper structures of the brain. The clearest effect of caffeine, for about one or two average size and strength cups of coffee, is an increase in general bodily movement. When test animals have been given very large doses of caffeine, however, they actually show reduced general activity. The caffeine in two or three cups of coffee usually prolongs the amount of time an individual can do physical work. Caffeine has also been shown to shorten the time needed to recover from physical work.
These all seem like positive effects of caffeine. There are, however many problems with caffeine. The stimulating effects of caffeine are addictive, making some people dependent on their morning cup of coffee. Caffeine’s lift does not last long, and it may have just the opposite affect once it’s gone, making one feel tired and let down. People can develop a tolerance to caffeine. A person may need more caffeine to get the same kick he or she used to get from a small amount. It can also make the blood vessels smaller. This makes it harder to push blood through, so the heart beats faster. Some people who drink as little as two cups of coffee a day feel withdrawal systems twelve to twenty four hours latter. These symptoms can last up to a week.
Caffeine can cause many...