Reviewed by Louise Chang, MD

Regarded for thousands of years in the East as a key to good health, happiness, and wisdom, tea has caught the attention of researchers in the West, who are discovering the many health benefits of different types of teas.

Studies have found that some teas may help with cancer, heart disease, and diabetes; encourage weight loss; lower cholesterol; and bring about mental alertness. Tea also appears to have antimicrobial qualities.

“There doesn’t seem to be a downside to tea,” says American Dietetic Association spokeswoman Katherine Tallmadge, MA, RD, LD. “I think it’s a great alternative to coffee drinking. First, tea has less caffeine. It’s pretty well established that the compounds in tea – their flavonoids – are good for the heart and may reduce cancer.”

Although a lot of questions remain about how long tea needs to be steeped for the most benefit, and how much you need to drink, nutritionists agree any tea is good tea. Still, they prefer brewed teas over bottled to avoid the extra calories and sweeteners.

Here's a primer to get you started.

Health Benefits of Tea: Green, Black, and White Tea

Tea is a name given to a lot of brews, but purists consider only green tea, black tea, white tea, oolong tea, and pu-erh tea the real thing. They are all derived from the Camellia sinensis plant, a shrub native to China and India, and contain unique antioxidants called flavonoids. The most potent of these, known as ECGC, may help against free radicals that can contribute to cancer, heart disease, and clogged arteries.

All these teas also have caffeine and theanine, which affect the brain and seem to heighten mental alertness.

The more processed the tea leaves, usually the less polyphenol content. Polyphenols include flavonoids. Oolong and black teas are oxidized or fermented, so they have lower concentrations of polyphenols than green tea; but their antioxidizing power is still high.

Here's what some studies have found about the potential health benefits of tea: