What Is Caffeine?
Caffeine is a stimulant drug (alkaloid) found in tea leaves, coffee beans, and in nearly 60 other plants. Caffeine is also commonly found in soft drinks, chocolate candy bars, and hot chocolate drinks. In addition to its presence in tea and coffee drinks, it is widely used as an ingredient in pain medications.
Caffeine drinks have been around for nearly 5,000 years; first in tea from China and later in coffee from Africa.
What Does Caffeine Do to Your Body?
Caffeine is addictive but, unlike many other addictive substances, does not require ever-increasing amounts to give you the same effect. Many people need a cup of coffee first thing every morning to wake them up and get them started. If you are caffeine-addicted, you will likely have a headache if you don't get your daily dose of caffeine.
Caffeine is a diuretic, meaning that it increases urine output and fluid losses. For example, when you drink a cup of coffee, you will excrete about half of the fluid content of the coffee within several hours. This is a higher percentage of fluid loss than if you drink an equal amount of water or juice.
Caffeine temporarily raises blood pressure. If you have high blood pressure, your doctor might tell you to cut down or eliminate coffee, tea, colas, and other high-caffeine products.
Unless you are caffeine-sensitive, most experts agree that moderate amounts will not be harmful to your body. When taken as a pain killer, usually in pill form, medications with caffeine have been shown to be effective pain blockers.
Many doctors recommend that pregnant women cut down or try to eliminate caffeine in their diet. The studies of the effects of caffeine on pregnant women and unborn babies have shown mixed results.
High doses of caffeine (the dosage may vary for different people) can cause dizziness, anxiety, irritability, insomnia, headaches, or upset stomach.
How Much Is Too Much?
There has been much discussion but little agreement on how much caffeine is too much. Several international organizations cite 300 milligrams a day as a moderate intake of caffeine. This is equal to about three cups of coffee or six cups of tea.
The American Medical Association and American Heart Association both state that moderate amounts of caffeine are generally not dangerous to most people.
If you get the jitters or your heart races from one cup of coffee, then that is too much for you. If you can't sleep after drinking a cup of coffee, then don't drink coffee in the evening. There is a wide variability in the amount of caffeine people can tolerate before having negative symptoms.
If you are trying to reduce caffeine intake, it may be more comfortable to do it slowly. Cutting down your coffee drinking by one-half cup every other day, drinking half-decaffeinated coffee, or drinking several fewer cola drinks each week over a period of time can reduce your need for caffeine without the headaches common to most who quit cold turkey.
The Bottom Line
Caffeine is a popular although addictive drug that, in moderation, does not appear to have negative health implications for most adults. There will be many more studies and much more written about caffeine. Future information could change current beliefs, or it could further strengthen what is already known. Stay tuned. |
