Green and black tea may have more health benefits than their well-known calming effect. Several compounds in these leafy plants have been examined in numerous studies and are linked to having beneficial effects on conditions ranging from mental health to cancer.
Of course, tea is not a magical cure-all potion, and its benefits are likely small. But there are few downsides when it comes to drinking tea — it's seldom harmful to health (except, of course, when taken in superhumanly high amounts).
Here are some of the potential benefits of tea on the brain and the body.
Feeling forgetful lately? Tea might help. A study published in March in the journal Psychopharmacology (opens in new tab) has found that green tea may improve some brain functions, including working memory, the type of memory we use to actively hold pieces of information, like the number we are about to dial.
In the study, 12 healthy people randomly received either a drink containing 2.75 grams per liter of green tea extract, or the same drink without the green tea. Results from brain imaging and working memory tests suggested green tea improved both people's performance in tests, and their brain connectivity between the frontal and parietal brain regions.
These results are in line with previous research that found better performance in memory-related tasks among people who regularly drink tea compared to non-tea drinkers.
Drinking tea could be as good as a mouthwash. The compounds found in black and green teas may limit the growth of bacteria that cause cavities, infections and gum disease, studies have suggested. In one study, researchers found that people who rinsed their mouths with black tea for one minute, 10 times daily, had less plaque buildup on their teeth than people who rinsed their mouths with water.
However, if you decide to use tea as a mouthwash, citrus and fruity tea may not be the best options, as their higher acidity may erode teeth.
Reducing cancer risk
Some compounds found in green tea, called polyphenols, are believed to have some anti-cancer properties, at least in lab tests. Researchers note that it's much more difficult to reach a conclusive verdict on whether a compound truly thwarts cancer in people.
But some studies have provided promising evidence about polyphenols.
One study that examined the tea-drinking habits of more than 500 people found that the risk of lung cancer was five times higher in those who did not drink green tea.
Moreover, some studies suggest drinking green tea may help breast cancer patients fare better in the disease progression, by limiting the growth of the tumor. It is possible that polyphenols suppress proteins that help cancer cell grow, according to studies in animals.
Improving muscle strength
Some studies have suggested that tea can improve muscular strength, by reducing the age-related oxidative stress and inflammation that break down muscles and bones.
In a study funded by the National Institutes of Health's center for Complementary and Alternative Medicine, researchers gave 170 post-menopausal women either a placebo, tea, or asked them to perform Tai Chi exercises. After six months, the women who drank the tea alone, performed Tai Chi alone, or combined the two all improved their muscle strength, compared with those who took only the placebo.
Editor's note: This article was updated on Sept. 22, 2014 to reflect a correction the researchers made to their article. In the journal, they noted that their article originally stated the research was based on consuming a drink containing 27.5 grams of tea, but the correct amount was 2.75 gram per liter.