Green Tea, Black Tea: Packed With Antioxidants
"The scientific evidence about tea is evolving and I think it's compelling," Jeffrey Blumberg, PhD, of the Friedman School of Nutrition Science and Policy at Tufts University, tells WebMD.
Tea is a great example of the past decade's research of antioxidants, he says. "There is a pretty consistent body of evidence suggesting there is a benefit to tea. Tea is a very rich source of a specific kind of antioxidant called flavonoids."
The detoxifying effect of these antioxidants protects cells from free radicals, the damage that can lead to blood clot formation, atherosclerosis, and cancer, says Weisburger.
The bulk of research shows that regular tea drinkers, people who drink two cups or more a day, have less heart disease and stroke, lower total and LDL (often called "bad") cholesterol, and that they recover from heart attacks faster.
Some laboratory tests also show that black and green tea may help boost metabolism to aid weight loss, block allergic response, slow the growth of tumors, protect bones, fight bad breath, improve skin, protect against Parkinson's disease, and even delay the onset of diabetes.
In a study involving bladder cancer cells, green tea extract seemed to make the cancer cells behave oddly. They matured sooner, bound together tightly, and had a hard time multiplying. Another study found that men who drank oolong tea plus green tea extract lost more weight and total body fat, compared with men who drank plain oolong tea. Also, the green tea drinkers had lower LDL cholesterol.
Other small studies have found that the antioxidants from drinking tea can help prevent skin cancer. There's also evidence that tea extracts applied to the skin (in a lotion) can block sun damage that leads to skin cancer.
All this research seems to suggest that if you want to do something good for yourself, drink tea. "It has no calories and lots of polyphenols. If you're drinking tea, you're not drinking soda -- that's a real benefit. Water doesn't give you those polyphenols," says Blumberg.
Weisburger recommends drinking six to 10 cups of black or green tea throughout the day, starting with breakfast. Switch to decaf tea midday, if you need to. "Flavonoids are unchanged by removal of caffeine," he says.