Are you having back pain with any of the following?

  • Severe pain, weakness or tingling in your leg(s).
  • Difficulty stopping urination or loss of control of bladder or bowels.
  • Unexplained fever, nausea or vomiting.
  • A history of cancer or unexplained weight loss.

We understand that you are experiencing one or more of the health issues that might be impacting your back pain.

We recommend that you discuss these health issues with your doctor before proceeding with this program.

Once you are cleared by your doctor to do this program, we hope it helps you find relief from your back pain.

Cancer Care

Santa Clara Medical Center

News & Events

Dr. Pan and Dr. Lee's Blog

Green Tea and Cancer

Jun 15, 2010

By Dr. Minggui Pan

Recently I was asked about drinking green tea and its effect on cancer prevention. I personally drink green tea every day as a habit. I prepare the tea by seeping a teaspoon of baked tea leaf with approximately 16 ounces of hot water for 10 minutes. I enjoy many different kinds of green tea.

Green tea is widely consumed in many parts of the world, especially in Asia. The Chinese have been drinking green tea for at least three to five thousand years. Tea is often the first thing that is served to friends at a visit or gathering. Drinking tea is an integral part of culture in most parts of China. The pot used to prepare tea is said to impact the tea’s flavor greatly. An elegantly made China teapot can be quite expensive. I personally have little experience in this and use a cheap teapot that I bought from an Asian grocery store. But I can tell the tea that I was served when I returned to China seemed to have a much better flavor than the tea I prepare for myself when I came back to the U.S.

The variety of green tea is large and diverse, but all from one type of plant called Camellia senesis. The way the green tea is made varies greatly and gives different flavor.


Green tea contains rich antioxidants called catechins. These antioxidants are released when green tea is seeped with hot water for several minutes. Instant ice tea contains little antioxidants. There are also green tea capsules. The amount of antioxidants and caffeine varies in different preparations.

There is also evidence that these antioxidants inhibit cancer cell growth in laboratory experiments. One such study a few years ago was featured in the magazine Science Daily. There have been many such laboratory studies regarding the tea’s effect on cancer cells and in animals.

There have been many clinical studies performed on green tea and its effect on human health including prevention of cancer. Most of these studies are retrospective. The evidence about green tea’s health effects is not still conclusive.

However, several major studies have been published in mainstream medical journals.

A study from Japan reported in JAMA, showed that consuming green tea was associated with a lower rate of mortality, especially lower rate of cardiovascular disease, but not lower rate of cancer.

Another study from Japan a few years found no beneficial association of green tea with reduction of stomach cancer incidence. This was published in the New England Journal of Medicine.

Two other studies from China showed that regular consumption of green tea seemed to lower the risk of cancer. A recent study published in Cancer Prevention Research showed some positive result as well.

Possible adverse effects of green tea

Would drinking green tea have adverse health effect? A recent study found that green tea may impair the anti-cancer effect of a drug called bortezomib, bring up caution for drinking green tea during treatment with this drug. Bortezomid is used in treatment of multiple myeloma, cancer of a blood cell called plasma cell.

It is also advised that during chemotherapy and radiation therapy, the amount of green tea consumed should be moderate, because there is plausible evidence that green tea might impair the effect of cancer treatment.

Green tea contains vitamin K. There are case reports that drinking large quantity of green tea can reduce the blood thinning effect of coumadin (wafarin). If you take wafarin for preventing blood clot and also regularly consume green tea you should report it to the anti-coagulation clinic.

This NIH web information on green tea discusses many aspects of green tea and its impact on health including safety and interaction with drugs.

Other effects of green tea

Green tea also contains caffeine. If you are sensitive to caffeine you may want to avoid drinking tea in the evening to avoid insomnia. Caffeine can cause feelings of apprehension when consumed in large quantity.

Patients with diabetes should take caution as well, because there are reports that drinking large quantity of green tea can lower your blood sugar.

Pregnant and breastfeeding women should avoid drinking large quantity of green tea because there are reports of spontaneous abortion and other negative impact on fetus.

Additional References and Links:

Destination health: Stopping cancer before it starts

Focus on cancer prevention, screening, treatment, and research

2019 "Eat Well, Heal Well Live Well" Resources and Educational Session Links

Resources and educational links for our 2019 Seeds of Hope.

2018 Healthy Body, Healthy Mind Resources and Educational Session Links

Resources and educational links for our 2018 Seeds of Hope.

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