Caffeine

What Is Caffeine?
Caffeine is a drug that is naturally produced in the leaves and seeds of many plants. It's also produced artificially and added to certain foods. It's part of the same group of drugs - xanthines - that includes theophylline, which is sometimes used to treat asthma.

Caffeine is defined as a drug because it stimulates the central nervous system, causing increased heart rate and alertness. Most people who are sensitive to caffeine experience a temporary increase in energy and elevation in mood.

Caffeine is in tea leaves, coffee beans, chocolate, many soft drinks, pain relievers, and other over-the-counter pills. In its natural form, caffeine tastes very bitter. But most caffeinated drinks have gone through enough processing to camouflage the bitter taste. Many young people get the majority of their caffeine intake through soft drinks, which can also have added sugar and artificial flavors.

Got the Jitters?
Many people feel that caffeine increases their mental alertness when taken in moderate amounts (like a single can of soda or cup of coffee). But higher doses of caffeine can cause anxiety, dizziness, headaches, and jitters that can interfere with normal sleep. And very high doses of caffeine - like a whole box of alertness pills - are harmful to the body.

Caffeine is addictive and may cause withdrawal symptoms for those who abruptly stop consuming it. These symptoms include severe headaches, muscle aches, temporary depression, and irritability. Although scientists once worried that caffeine could stunt growth, this concern is not supported by research.

Caffeine sensitivity refers to the amount of caffeine that will produce an effect in someone. This amount varies from person to person. On average, the smaller the person, the less caffeine necessary to produce side effects. However, caffeine sensitivity is most affected by the amount of daily caffeine use. People who regularly drink beverages containing caffeine soon develop a reduced sensitivity to caffeine. They require higher doses of caffeine to achieve the same effects as someone who doesn't drink caffeinated drinks every day. In short, the more caffeine you take in, the more caffeine you'll need to feel the same effects.

Caffeine moves through the body within a few hours after it's consumed and is then passed through the urine. It's not stored in the body, but someone who's sensitive to caffeine may feel its effects for up to 6 hours.

Although you may think you're getting plenty of liquids when you drink caffeinated beverages, caffeine works against the body in two ways: It has a mild dehydrating effect because it increases the need to urinate. And large amounts of caffeine may cause the body to lose calcium and potassium, causing sore muscles and delayed recovery time after exercise.

Caffeine has health risks for certain users. Small children are more sensitive to caffeine because they have not been exposed to it as much as older children or adults. Pregnant women or nursing mothers should consider decreasing their caffeine intake, although in small or moderate amounts there is no evidence that it causes a problem for the baby. Caffeine can aggravate heart problems or nervous disorders, and some may not be aware that they're at risk.