Pour a cup of tea for your health

Start sipping your way to better health.

Tea has been used as a folk remedy for 5,000 years — to aid liver function, destroy typhoid germs, purify the body and preserve mental equilibrium — and now scientists are discovering it may have all those benefits and a whole lot more.

Studies presented this fall at the Fourth International Scientific Symposium on Tea and Human Health, hosted by the U.S. Department of Agriculture, showed that tea can be key to a healthful diet.

“As a nutrition scientist, I consider tea as a healthy choice for three reasons: It meets hydration needs, it has no calories and it’s really rich in phytonutrients (plantbased substances) that we know provide some human health benefits,” Jeffrey Blumberg, director of the Antioxidants Research Laboratory at Tufts University in Boston, said by telephone. “Tea has more of the catechins (phytochemicals that act as antioxidants) than any food I am aware of. It is far and away the biggest, richest best source of those phytonutrients.”

We asked Blumberg, cochairman of the symposium, about tea and health:

Question: Are green, black and oolong teas equally healthful?

Answer: I don’t know of any controlled trials comparing the different colors of tea, but all of them come from the same plant, the Camellia sinensis bush, and there is a huge overlap in what we are finding in different studies using different kinds of tea. Most of the observational studies use green tea in Japan and China and black tea in the U.S., India and Great Britain, but they all show the same results. One study looked at models of digestion and found that in the gut, bacteria and enzymes break down different kinds of tea so that when it gets to human tissue, they are all pretty much the same.

Q: Do you get the same health benefits from taking tea supplements?

A: There are not very many studies on tea supplements, yet the few that we have suggest they are mimicking some of the cardio and cancer benefits established in tea studies. You are going to get some of the same benefits from tea extracts, but they are not the same thing. I have a slight bias as a nutrition scientist. Mother Nature put a lot of different beneficial chemicals and compounds in tea, so why not take advantage of all of them? By definition, supplements are 80 percent to 90 percent concentrated polyphenol extracts, primarily EGCG, a powerful antioxidant, but as far as I know, theanine amino acid is not in extracts, and theanine is what helps you to focus your attention (on a task) or relax.

Q: How much do you need to drink to get the health benefits of tea?

A: From lots and lots of observational studies, it looks like four to five cups a day will put you in the highest 20 percent for protection against heart disease and stroke. Those who drink four cups or more consistently have the lowest risk of heart disease. There is definitely a dose/response relationship.

Q: Can you drink too much tea?

A: There is no evidence of harm in healthy human beings, within a tremendous range (of doses). Tea is caffeinated — it has about half as much caffeine as coffee — so if you are caffeine-sensitive, you might want to drink decaf, but there is no evidence to suggest any adverse consequence from tea consumption. (But a recent report showed that a woman who drank 2 gallons of strong tea every day for two years developed calcium deposits in her bones, Blumberg said.)

BENEFITS OF TEA

Various studies presented at the Fourth International Scientific Symposium on Tea and Human Health showed that tea can:

- Reduce risk of heart disease and stroke

- Lower cholesterol c Repair smoking-related DNA damage

- Prevent colon, rectal, pancreatic, stomach, prostate and oral cancers

- Lower risk of developing kidney stones

- Speed up metabolism

- Decrease body weight and fat

- Control blood sugar

- Lower the risk of osteoporosis

Other studies, conducted on animals, showed that tea may:

- Prevent and repair damage to brain cells

- Delay cognitive decline seen in Parkinson’s and Alzheimer’s disease

- Create a calmer, yet more alert state of mind