A tea timeout is my favorite way to de-stress a day. It feels so civilized to relax with a warm cup of jasmine-scented green tea or perhaps the traditional English treat, black tea with milk – white, as they say. Still, with all the myths we hear about nutrition, I’ve always wondered, is tea as healthful as many people believe?
Although tea has been enjoyed around the world for some 5,000 years, it wasn’t until relatively recently that scientists started searching for the facts.
From the 1970s to the 1990s, epidemiological studies – the kind following large populations’ eating and disease patterns – found tea drinking might be associated with better health. But no clear cause-and-effect relationship between health and tea was established.
More careful clinical and laboratory studies are needed, said Johanna Dwyer, a professor at Tufts Medical School in Boston, at the fifth International Scientific Symposium on Tea and Human Health held Sept. 19.
But recent studies have been promising. What did they find? Just about every cell in the body could potentially benefit from tea – with virtually no downsides.
All true tea (white, green, oolong and black, as opposed to herbal varieties) comes from one plant: Camellia sinensis. The differences are in how they are processed, with white and green being the least processed, oolong in the middle and black the most processed.
The processing changes the nutritional profile and some of the health effects. But no matter the process, all tea leaves are dense with flavonoids, health-promoting chemicals found in fruits, vegetables, whole grains and most plants.
About one-third of the weight of a tea leaf is flavonoids, which is high, especially when you consider there are virtually no calories, said Jeffrey Blumberg, professor of nutrition science and policy at Tufts University and chairman of the tea symposium. A serving of tea is like adding a serving of fruits or vegetables to your diet.
But can tea produce more health benefits than fruits or vegetables? Flavonoid research results are exciting but mixed, and there is still a lot to learn.
There are small but possibly significant health effects, but study quality needs to improve, Dwyer said, adding, Tea is not a drug, and to expect a drug-like effect is unrealistic.
So, while not a miracle cure-all, there is some exciting news about tea:
It helps your heart by keeping blood vessels unclogged and flexible. Blood pressure and stroke risk were reduced in epidemiological and clinical studies (even with sugar added).
In a double-blind, randomized study in which hypertensive men drank one cup of black tea daily, both systolic and diastolic blood pressure were reduced.
Healthier blood vessels create better blood flow, which means all of your organs, including the brain, are receiving more blood, oxygen and nutrients, enhancing your body’s ability to fight disease. So, healthier blood vessel linings might be one reason why tea consumption seems associated with so many benefits.
It improves bone health. After drinking four to six cups of green tea daily for six months, post-menopausal women with low bone mass (osteopenia) achieved an improvement in certain short-term measures of bone health in a National Institutes of Health-funded study conducted at Texas Tech University Health Sciences Center.
They also improved muscular strength. Tea reduced oxidative stress and inflammation, preventing the usual bone and muscle breakdown.
It can help your thinking. When your brain receives better blood flow and oxygen, and inflammation and oxidative stress are reduced, there is improved cognitive function, according to studies.
It might reduce cancer risk. Many animal and test-tube studies have found anti-cancer effects of tea, but human studies have been less consistent.
It can help you lose weight. Not only does tea have fewer calories than most beverages (zero without milk and sugar), but certain compounds in tea, and especially green tea, have been found to burn body fat.
Tea is not a drug, which means the health effects are mild and might not even be noticeable, depending on your genetics.