Traditional Chinese Medicine Information Page

Fighting Cancer with Soy and Other
Popular Chinese Foods

One out of three people alive today in the United States will ultimately die of cancer. More and more often, people in this country, including health professionals, are questioning the conventional treatments for cancer. Are surgery, chemotherapy, and radiation therapy the only options for cancer patients? Interestingly, since surgery, chemotherapy, and radiation therapy became the standard treatments for all cancer patients, data indicates no improvement in either the incidence of cancer or the survival rate. Many people are now turning to Eastern medicine to try to find an answer. Increasing numbers of people ask me how Chinese medicine deals with cancer: if there is hope for a cure, and what preventive methods are used.

We all know that many types of cancers are diet-related. It is estimated that 60% of cancers in women are diet-related. Evidence shows that some foods increase the likelihood of developing cancer, while others reduce the likelihood of developing cancer. In Chinese medicine, diet is considered to be a major factor in cancer prevention. Many foods have been tested scientifically and found to contain anti-cancer agents. Some of the most exciting research has been done on soy beans and soy food products.

Soy beans are considered to be one of the five sacred foods in China. For a typical Chinese family, every meal includes soy foods: soy milk for breakfast; tofu salad at lunch; tofu and vegetable stir-fry for dinner. Even at a formal banquet, you would see many soy-based dishes, often marinated with garlic, sesame, soy sauce, or ginger. Soy products can be easily made into noodles, breads, and snack foods, and are wonderful substitutes for meat, chicken, eggs, and cow’s milk.

Although Asian people have long claimed that soy foods promote increased health and longevity, it is only recently that Western researchers got around to performing scientifically controlled, double-blind studies on soy beans and their chemical constituents. When Asian scientists pointed out that cases of breast cancer and prostate cancer are significantly lower in Asian countries than in Western countries, and attributed this fact to diet; and when it was further pointed out that American women who consume soy foods have a fifty-percent lower incidence of cancer than women who don’t eat soy, many Western scientists decided it was time to investigate these phenomena.

So far, it has been discovered that soy beans contain at least five known anti-cancer agents, including protease inhibitors, phytoestrogens, saponins, and genistein. People have aware for decades that soy beans contain protease inhibitors, but it was thought that protease inhibitors interfered with proper digestion, so they were actually removed from all soy products produced in the United States. Only now are protease inhibitors recognized as valuable cancer fighters that inhibit tumor growth by inhibiting the action of certain enzymes that promote tumor growth.

Most people, including most health professionals, had never heard about genistein until 1993, when Dr. Herman Adlercreutz’s research on prostate cancer was cited in the Wall Street Journal. Genistein, a type of phytoestrogen, blocks the signal that triggers normal cells to become cancer cells, and is extremely effective in stopping the growth and spread of prostate cancer. Scientists have speculated that genistein may even be used as a cancer treatment. Although more than three hundred plants contain phytoestrogens, only soy beans produce genistein.

Phytoestrogens, which are heavily concentrated in soy, seem to create a favorable hormonal environment which prevents certain cancers from developing, especially breast cancer. The phytoestrogens in soy have a similar chemical structure to the estrogen produced by the body, but phytoestrogens are considered to be "weaker" than the body’s natural estrogen. "Strong" estrogens which bind to the body’s estrogen receptors are recognized as being a triggering mechanism in the development of breast cancer. Unfortunately, the women in "advanced" countries have not only their naturally-produced estrogen to deal with, but also the strong estrogens that come from the environment – from water, from meat, or leached into our foods and beverages from plastic containers. When soy is consumed, the natural weaker estrogen in the soy binds with the body’s estrogen receptors, thus leaving fewer estrogen receptors available for the risky, stronger estrogen which is then discharged harmlessly from the body. The faster strong estrogens are metabolized and discharged, the less damage they can cause.

Until recently, soy beans have been under-appreciated in this country, and are often associated with animal fodder or extreme poverty. When I first came to America, I would extol soy foods to my patients, only to be met with skepticism. "Soy beans? That’s cow food," said one. A journalist told me he had eaten a lot of soy foods when he was a poor student. It is a big challenge for Americans to switch from meat and potatoes to tofu and soy milk, but health-conscious people are beginning to change. Increasingly, people come to my clinic for consultations on cooking and eating soy foods. I have heard of women who rushed out to the grocery store to buy soy when they heard about its potential to prevent breast cancer. I am so glad that people here in the United States have finally begun to recognize the benefits of these "Cinderella beans."

Now that a variety of soy products are available in many city markets, it is well to recognize that some of them contain more phytoestrogens than others. In order to enjoy the maximum benefit from soy foods, I recommend that you purchase organically-grown soy beans whenever possible, and learn to make your own soymilk at home. Included in this section is a recipe for soymilk, as well as a delicious vegetable stir-fry recipe.