Coffee combats drowsiness, temporarily boosts athletic performance, eases congestion due to colds and flu, prevents asthma attacks and enhances the pain-relieving effects of aspirin. It is America's most popular herbal beverage. Of course, coffee can also cause problems -- jitters and insomnia. However, the latest research says, "Coffee appears to pose no particular threat in most people if consumed in moderation."

Coffee has been around for a long time. Our word coffee comes from Caffa, the region of Ethiopia where the beans were first discovered. The beverage we know as coffee emerged around A.C.E. 1000, when Arabians began roasting and grinding coffee beans and drinking the hot beverage as we do today. Until the 17th century, Arabia supplied all the world's coffee through the port of Mocha, which became one of coffee's names. Then the Dutch introduced the plant into Java, and the island quickly became synonymous with coffee.

The medically important constituent of coffee is, of course, caffeine, but coffee's caffeine content depends on how it's prepared. A cup of instant contains about 60 milligrams of caffeine whereas drip or percolated coffee has about 100. A cup of espresso contains about 100 milligrams, but this is in a 2 1/2-ounce cup.

Caffeine is addictive. Regular users develop a tolerance and require more to obtain the expected effect. Deprived of caffeine, regular users usually develop withdrawal symptoms, primarily a headache, which can last several days. Coffee is most notorious for causing insomnia and increasing anxiety, irritability and nervousness. It can also aggravate panic attacks. Coffee increases the secretion of stomach acids and can upset the stomach. Doctors say that people with ulcers or other gastrointestinal conditions should use it cautiously, if at all. Contrary to popular mythology, coffee does not cause ulcers. It can, however, make ulcers worse in people who already have them.  Coffee also raises blood pressure in those who are not accustomed to drinking it. But the body adjusts, and normal consumption no longer affects blood pressure.

Coffee has been associated with some bad news.  One of which is heart disease. The subject is extremely controversial, with evidence supporting both sides of the argument. Most studies indicate that coffee can increase cholesterol levels. Decaffeinated coffee has the same cholesterol-boosting effect as regular, suggesting that caffeine is not the culprit. However, filtered coffee doesn't raise cholesterol as much as boiled coffee. It may also increase the risk of heart attack if one consumes more than four cups a day.  There are reports that coffee aggravates premenstrual syndrome in many women.  Coffee has also been accused of contributing to infertility, birth defects, gallstones, immune impairment and many forms of cancer but none of these have been proven. 

If you want to drink coffee, two cups per day is generally what doctors will recommend.