Food experts, who have warned that the caffeine in coffee may cause everything from cardiovascular disease to cancer, are changing their tune. They now say moderate caffeine intake is safe, so people can relax and indulge in several daily cups of coffee or tea.

Nutrition scientists who convened last fall at a meeting of the American Dietetic Association (ADA) noted that new studies--plus a review of existing work--show caffeine has no harmful effect on the human body. Earlier reports linking caffeine to breast cancer, high blood pressure, osteoporosis, and other diseases, they say, may have been hasty or based on too-small studies.

Moderation = 3 Cups a Day

The United States Food and Drug Administration (FDA) and the National Institutes of Health (NIH), two of the most respected US watchdog agencies, have declared caffeine safe. Even the American Medical Association (AMA) says coffee and tea drinkers "probably need have no concern for their health relative to their caffeine consumption" as long as the intake is moderate.

Moderate coffee intake is generally defined as 3 cups a day. That delivers 300 milligrams (mg) of caffeine, since an 8-ounce cup usually holds about 100 mg. The same size cup of tea holds some 40 mg of caffeine. Many soft drinks contain about 24 mg of caffeine, and chocolate ranges from 6 mg in an 8-ounce cup of cocoa to 26 mg in 1 ounce of baker's chocolate. Many processed foods also have small amounts of caffeine added to enhance flavor.

Coffee Craze Spurred Investigation

Caffeine is a natural substance found in at least 60 plants. Coffee beans were originally consumed as food in Africa, and tea was invented in China, allegedly when leaves drifted into a pot of boiling water and created a delicious liquid. Chocolate drinks were used by the Aztec emperor Montezuma in the early 1500s to welcome Spanish explorers, and caffeinated soft drinks became the rage in America in the 1880s. These treats quickly spread around the world, and caffeine has been a dietary staple ever since.

Scientists in the United States began taking a close look at caffeine in the late 1980s, when specialty coffees and neighborhood "coffee bars" spurred consumption. A variety of studies suggested that coffee drinkers might be more prone to heart disease and hypertension, and one small study done in 1988 alarmingly suggested that 1-2 cups of coffee a day might make it harder for women to conceive. Although follow-up studies have not supported this conclusion, this led to a myriad of myths about caffeine, including suggestions that it is bad for children and pregnant women and that it can become addictive.

No Such Thing as a Coffee Addict

"Caffeine is not a drug, and you can't get addicted to it," says Edith Howard Hogan, a Washington, DC, expert in nutrition who is a national spokesperson for the ADA. "Caffeine doesn't build up in the bloodstream, and doesn't stay in the body for long. You can get dependent on having a cup of coffee, and feel unhappy if you don't get it, but that's very different from addiction. An addict needs more and more of a substance, and very often that substance is harmful to the body. People don't crave more caffeine, and in reasonable amounts it's perfectly safe."

Hogan notes that misconceptions about caffeine and coffee consumption hurt nutrition researchers, because people get fed up with confusing reports and tend to disregard important information when it does surface. "Scientists and the media need to do a better job of telling consumers when information is based on preliminary studies and when something comes out that really is important," she says. "Sometimes it's hard to tell the difference."

Setting the Record Straight

Lately, scientists have been scrambling to set the record straight about caffeine. Larger studies looking at breast cancer and fibrocystic breast disease have found no evidence to implicate caffeine, prompting the American Cancer Society to declare, "There is no indication that caffeine, a natural component of both coffee and tea, is a risk factor in human cancer."

The Centers for Disease Control and Prevention (CDC) in Atlanta, in a joint study with Harvard University, found coffee was safe for pregnant women and for those wishing to conceive. The Association of Women's Health, Obstetric & Neonatal Nurses says moderate intake of caffeine isn't a factor in miscarriages, birth defects, low birth weight, or breast feeding. Caffeine can spur some increase in calcium loss, say the nurses.

Although consuming 1-2 cups of coffee per day is common in our society, caffeine is considered a risk factor for osteoporosis. People with osteoporosis or at high risk for developing it should seriously consider significantly limiting caffeine intake.

May Even Have Health Benefits

Caffeine seems to be harmless as long as you use common sense and don't consume more than your body can handle. Children can also safely indulge in caffeinated beverages as the effects seem to be similar in adults and children--even those who are hyperactive seem to tolerate it well. (Humans don't develop the necessary machinery to effectively metabolize caffeine until somewhere between 6 months and 2 years, and therefore it is better to avoid caffeine in kids less then 2 years old.) Caffeine won't cause dehydration, either, because you'll probably ingest more water in the coffee and tea than you lose as a result of the caffeine.

Caffeine may even have health benefits: It does enhance motor skills, reaction time, and reasoning power, and is being investigated as an aid in dissolving kidney stones. There is even some preliminary scientific evidence suggesting a link between drinking filtered coffee and a rise in high-density lipoprotein (HDL), the "good" cholesterol.

Experts now agree that each individual should decide if drinking caffeine-containing beverages is right for them. Some people think of coffee or tea as one of life's pleasures; others are supersensitive to caffeine and say it results in heartburn, or makes them irritable. "The best advice is to go with how the caffeine reacts in you," says Hogan. "You know your body better than anyone else."