It's November, and the chill is on. Instead of reaching for a calorie-dense vanilla café latte to warm you up, try a cup of tea, the second most popular beverage in the world (after water, not lattes). Made from leaves of the Camellia sinensis plant, teas' distinct tastes and colors—black, green, oolong, and white—arise from how the raw leaves are processed: steamed, fermented (oxidized), dried, or bruised. Studies show that all types offer superb health benefits. Find out why you should keep refilling your teacup throughout winter's chilly days.

How much tea should you drink?
"The more the better, but anything more than ten cups a day may be overkill," says tea expert Jack Bukowski, MD. If you have a choice, remember that cup for cup, "green tea has more antioxidant activity and immune-boosting activity than any other tea."

—H.K.J.

An army of antioxidants
Tea positively brims with antioxidants, food compounds that work to neutralize harmful free radical molecules, which over time can damage cells and contribute to chronic and age-related diseases. An average cup of brewed green or black tea provides 150 to 200 mg of these immune-boosting flavonoids. Green tea in particular offers copious amounts of epigallocatechin gallate (EGCG), an antioxidant considered the key to green tea's healthy qualities. In fact, recent human studies suggest that the EGCG in green tea may contribute to a reduction in cardiovascular disease risk and some forms of cancer. It may even keep your teeth plaque free (Caries Research, 2006, vol. 40, no. 3).

Cancer prevention
Researchers link a mere one daily cup of tea—especially green tea—with decreased cancer risk, particularly the recurrence of breast and ovarian cancer (International Journal of Cancer, 2004, vol. 112, no. 3; Japanese Journal of Cancer Research, 1998, vol. 89, no. 3). Because of its abundant antioxidants, "green tea ... is a potentially helpful component of an optimal anticancer diet, so much so that I consume three to four 8-ounce cups of green tea daily," says Diana Dyer, registered dietitian, cancer survivor, and author of A Dietitian's Cancer Story (Swan Press, 2002).

Heart health
In one study of more than 3,000 Saudi Arabian adults (who generally favor black tea over green), researchers found that those who drank more than six cups of this dark brew per day reduced coronary heart disease risk by 50 percent (Preventive Medicine, 2003, vol. 36, no. 1). "Tea isn't a magic bullet," says Jack Bukowski, MD, an assistant professor of medicine at Harvard Medical School and an expert on tea's health properties, "but there are strong suggestions that tea enhances heart health, thanks to its antioxidant activities." Studies suggest that drinking at least three cups of black tea a day may be associated with a modest decrease in heart attack risk.

Herbal teas
Tisanes, or herbal teas, do not derive from the Camellia sinensis plant. Instead, they're infusions of herbs, flowers, leaves, roots, bark, or berries from other plants. Many are delicious, and may offer health benefits of their own, but not the same benefits of traditional tea.

—H.K.J.

Weight management
Preliminary research indicates that drinking tea may help speed fat metabolism (Obesity Research, 2005, vol. 13, no. 7; Life Sciences, 2004, vol. 74, no. 19; International Journal of Obesity and Related Metabolic Disorders, 1999, vol. 23, no. 1), but the jury's still out on whether drinking tea really helps people lose weight, says Bukowski. If nothing else, opting for tea means you'll be filling up with a warm, nearly calorie-free liquid, helping you stave off hunger pangs and the temptation to reach for less healthy options.

Peace and quiet
Perhaps tea's most overlooked health benefit stems from the simple act of making time for reflection and stress release. In the traditional Japanese tea ceremony called chanoyu, tea masters use the process of making and drinking tea to meditate on the principles of harmony (wa), respect (kei), purity (sei), and tranquility (jaku), hoping to integrate these ideals into daily life. Whether you put on a pot of tea for yourself or a group of friends, use your teatime for reflection, enjoyment, and a conscious sense of peace.

H.K. Jones is a registered dietitian, freelance writer, and avid tea drinker in Washington, D.C.