Healthnotes Newswire (February 5, 2009)—Green tea has a reputation as an elixir of health. Are these accolades well-earned? When it comes to cancer prevention, the answer is a qualified “maybe.”

Current consensus

Researchers at Beijing University in Beijing, China; the National Research Centre in Complementary and Alternative Medicine in Tromso, Norway; and RMIT University in Melbourne, Australia; combed through 48 research papers on green tea and cancer risk. They considered whether regular green tea drinking reduced risk of several cancer types including oral and esophageal, stomach, pancreatic, liver, biliary duct, colorectal, breast, lung, prostate, bladder, endometrial, ovarian, and adult leukemia.

The researchers write that most existing green tea and cancer research is of poor quality, which makes it difficult to draw meaningful conclusions and to compare one study to another. While 58% of studies suggest drinking green tea may reduce cancer risk, there is no one type of cancer for which the evidence conclusively supports green tea’s cancer-preventive properties.

The authors conclude that evidence is strongest for green tea and reduced risk of gastrointestinal tract, breast, lung, and prostate cancers, but even for these tumor types, evidence is not conclusive.

The bottom line

While it may not yet be a proven cancer-prevention powerhouse, the majority of studies point to some cancer-prevention benefits of regular green tea consumption. And it is a delicious beverage, calorie-free and lower in caffeine than coffee, which makes it a great choice for an afternoon pick-me-up.

Green tea brewing and sipping tips

• Green tea comes in many flavors, from plain to those with jasmine, mint, or citrus overtones. Experiment to find one you like best.

• Steep your green tea only for two to three minutes and then remove the tea bag or loose leaves. If you steep for much longer than this, you can “over-extract” the tea, leading to a bitter brew.

• Make green tea with water that is less than boiling. Boiling water can bring out tea’s bitter flavors, making a beverage that is too strong from some taste buds. Pour boiling water into your cup or teapot, let sit for five minutes to cool, add tea, and steep.

• If you are trying to limit caffeine, try a caffeine-free green tea variety. Studies show the majority of the compounds in tea that are believed to provide health benefits survive the decaffeination process.

• If you are pregnant or nursing, or have a cardiac (heart) condition, enjoy your green tea, but limit intake to two cups or less per day.

• If you currently are receiving cancer treatment, ask your doctor if it is okay for you to have green tea. One recent study suggests that a compound found in green tea may interfere with certain chemotherapy medications.

(Chin Med 2008;3:12; Blood, prepublished online February 3, 2009)