Regular tea drinkers may be getting more in their cup than they realize. Tea contains a family of naturally occurring chemicals – polyphenols – that researchers suspect may prevent disorders such as heart disease and cancer.
Tea leaves are processed differently to produce green, black and oolong teas. These are the basic teas, but there are about 3,000 variations in the tea plant family of Camellia sinensis (like Darjeeling or Orange Pekoe).
All three basic teas are dried and then crushed. However, green tea is not fermented but briefly steamed, rolled then crushed and quickly packaged. Black tea leaves are fermented; the leaves are warmed for a few hours, and then heated at higher temperatures to complete the drying stage. Oolong tea goes through less of a fermentation process than black tea.
Since it’s the least processed, green tea retains more of its polyphenol content – likely promising the most health benefits. Black and oolong teas also have polyphenols, although not as much as green tea. But black tea is rich in many other compounds with health-boosting abilities, such as flavonoids.
Research shows polyphenols, flavonoids and other chemicals act like antioxidants. Antioxidants fight against unstable molecules in the body called free radicals, which can damage the normal structure of cells and lead to diseases like cancer. Studies found green tea prevented tumour formation in rats and lowered blood cholesterol in rats and hamsters.
The few studies so far on humans look very promising in preventing many diseases and disorders, but they have conflicting results. Therefore, there’s no hard evidence yet on how well tea can protect our health nor how much is needed.
Herbal teas are not really considered “tea” because they come from other plants, not Camellia sinensis. However, herbal teas are used as effective natural remedies for many health issues.
Herbal teas also have no caffeine. Green tea and black teas offer up to 40 mg of caffeine – far less than the 100 to 200 mg in a cup of coffee – making tea less likely to give you the jitters. Tea is a good choice (as well as decaffeinated coffee) to wean yourself off coffee. It’s not advised to quit caffeine cold turkey – the withdrawal symptoms for even moderate coffee drinkers can be severe. Switching to tea, however, allows a more gradual withdrawal.
In any case, drinking tea isn’t the only way to ensure good health: It can’t replace the full health benefits of a sensible diet.
Researchers are continually discovering all kinds of health-protecting properties in many foods. The best guarantee you are getting all of them is to choose from lots of healthful foods and beverages – including tea.