Wouldn't it be great to find a drink that tastes good, quenches your thirst and improves your health, all at the same time? It's a tall order, but a glass of tea might just measure up.

Tea is one of the most popular beverages in the world: global consumption of the tasty brew ranks second only to water. While tea is a favorite in many countries, Americans traditionally have favored a slug of coffee over a spot o' tea.

These days, more health-conscious Americans are turning to tea, and with good reason. In the past decade, hundreds of studies have demonstrated its health-promoting and disease-preventing powers.

Tea is rich in polyphenols, natural plant compounds with potent antibacterial and antiviral properties. The polyphenols in tea also serve as powerful antioxidants.

In the body, these agents help neutralize free radicals — high-energy molecules that contribute to the development of a number of deadly diseases, including cancer.

The antioxidants in tea aren't the only ingredients that make it a powerful weapon in the war on cancer. A compound called epigallocatechin gallate (EGCg) appears to squelch an enzyme necessary for the growth of cancer cells.

When researchers at Case Western Reserve University School of Medicine applied EGCg to healthy and cancerous mouse cells, they found that the agent helped wipe out the cancer cells without harming the healthy ones.

Harvard scientists reported that the EGCg in tea has protective powers against cancers of the digestive tract. The researchers concluded that EGCg triggers the production of proteins that can repair DNA damage before it leads to cancerous changes in the esophagus or stomach.

In a study published in the medical journal Archives of Internal Medicine, researchers reported that women who drank two or more cups of tea per day had a 45 percent lower risk of ovarian cancer compared to women who never drank tea. Each additional daily cup of tea was associated with an 18 percent reduction in the risk of developing ovarian cancer.

A growing body of evidence suggests that drinking tea is good for your heart. In a study conducted at Boston University, researchers asked 50 men and women diagnosed with heart disease to drink four cups of black tea daily for four weeks.

Just two hours after downing the first cup, investigators found that drinking tea promoted widening of the subjects' arteries and significantly improved their blood flow.

Both actions have beneficial effects on the heart.

In addition to warding off cancer and heart disease, tea may boost the protective powers of the immune system. Drinking tea increases production of interferon, a substance known to play a key role in protecting the body against infection.

When researchers at Harvard Medical Center asked adult volunteers to drink five cups of black tea each day for four weeks, they found that their blood cells secreted five times more interferon than before they began drinking tea.

The results of a new study conducted by an international team of researchers from the University of Maryland and Cardiff University suggest that black tea could be an important line of defense against the threat of bioterrorism. The scientists reported that black tea can thwart the bacteria responsible for anthrax, a potentially deadly disease.

In March 2008, Egyptian scientists reported that green tea can help beat drug-resistant superbugs. Natural compounds in the beverage dramatically boost the action of antibiotics, making them up to three times more effective at killing disease-causing bacteria.

Recent animal studies suggest that drinking tea may be a simple, inexpensive way to help prevent diabetes and many of its complications. Researchers at the University of Scranton in Pennsylvania found that when diabetic rats drank the human equivalent of five cups of green or black tea daily, their blood sugar levels dropped and they had a reduced risk of developing cataracts and other diabetic complications.

Drinking tea has long been associated with relaxation, and now there's scientific proof. In the medical journal Psychopharmacology, British researchers reported that regular consumption of tea helps individuals recover more quickly from the stresses of everyday life.

The results of the study demonstrated that drinking tea not only helps normalize stress hormones in the body, it can lower stress-related rises in blood pressure and heart rate.

When it comes to tasty, health-promoting beverages, tea is hard to beat. The next time your coffee break rolls around, you might want to consider having a cup of tea, instead.

Rallie McAllister is a board-certified family physician, speaker and the author of several books, including "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her website is www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

COPYRIGHT 2008 CREATORS SYNDICATE INC.