Green tea extract may help to delay oral cancer in people at risk, new research suggests. Researchers gave green tea extract to 41 people who had pre-cancerous cells in their mouths. The dose was equal to 8 to 10 cups of green tea daily. Another group received placebos. The study lasted 28 months. In that time, people who took green tea extract were just as likely as the other group to develop oral cancer. But in one group who took green tea extract, the cancer took longer to develop. This was the group of people who had mild to moderate abnormal cell growth at the start of the study. Study results were released online by the journal Cancer Prevention Research. HealthDay News wrote about the study November 5.
By Diana Post, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Can something as "simple" as green tea help prevent cancer? We don't know yet. This study hints at some anti-cancer effects of green tea. But it is much too early to say more about the potential health benefits of green tea.
Many health products and practices fall outside the limits of "conventional" medicine. They are often referred to as complementary and alternative medicine, or CAM. CAM includes many things:
- Whole medical systems such as homeopathy or traditional Chinese medicine
- Specific treatments such as acupuncture
- "Hands-on" treatments such as massage therapy
- Herbs and supplements
CAM therapies are called "alternative medicine" when used in place of conventional medicine. Using them together with conventional practices is called "complementary medicine."
More recently, people have begun to use the term "integrative medicine." This term means the use of conventional treatments with CAM treatments that have at least some scientific evidence of safety and effectiveness. One example is the use of acupuncture to help manage the nausea caused by cancer chemotherapy.
Most doctors think that CAM treatments should receive the same scientific evaluation as conventional treatments. There is little or no scientific evidence to confirm that most CAM therapies are safe or that they do what people claim they do. Few CAM therapies have yet been through this type of rigorous scientific study. There have been claims that green tea improves alertness, helps weight loss, and lowers cholesterol levels. But there is little scientific research to support these claims.
CAM practitioners also have recommended green tea and extracts of green tea to prevent and treat a variety of cancers. Can green tea really help prevent cancer? A few studies suggest that green tea may protect against or slow the growth of certain cancers. However, human studies have been very limited and have shown mixed results.
This paper describes a small, preliminary study that looked to see if green tea can prevent oral cancer. It looks promising, and more study is certainly indicated. Perhaps an active ingredient eventually will be identified that can safely prevent cancer development or growth.
Clearly more work is needed.
What Changes Can I Make Now?
Remember that smoking or using tobacco products such as chewing tobacco are the major factors that increase the risk of developing oral cancer. So DON’T SMOKE or use tobacco products. - If you are thinking about using a CAM treatment, try to find out about its benefits and risks.
- Try to get information from a reliable source. Be careful when using the Internet to search for information. There are many unreliable websites out there! Check out a database developed by the National Institutes of Health (NIH) and the National Library of Medicine. Scientists in the same field have reviewed the articles cited and found them to be important and accurate.
- If you use a CAM therapy, tell your doctor. Some CAM therapies can interfere with standard treatments for certain conditions. For example, drinking a lot of green tea might make the blood-thinning drug warfarin less effective.
- If you want to take part in clinical trials studying CAM therapies, talk with your health care professional.
As a physician, I cannot recommend ever using unproven alternative treatments in place of scientifically studied conventional treatments for cancer. The use of CAM therapies added to conventional treatments should be discussed with your doctor.
What Can I Expect Looking to the Future?
The NIH now has a branch known as National Center for Complementary and Alternative Medicine (NCCAM). This center supports scientific studies to increase our understanding of CAM treatments. NCCAM supports studies about components in green tea, and their effects on cancer and other health problems. It also supports other research looking at CAM therapies and cancer prevention and treatment.
I am sure we will know much more about the effects of CAM therapies on cancer in the future. Perhaps we will know then if switching to green tea will really help us stay healthy. In the meantime, don't smoke!
