By Talia Beechick
Who knew that tasty, protein-packed soybeans actually contain a powerful cancer-fighting substance? ScienceDaily announced recently that scientists at the University of Missouri have discovered an easy and environmentally-friendly method of extracting the cancer-fighting properties of soybeans to reap their benefits in the fight against cancer.
According to the American Cancer Society the disease affects nearly 12 million people in the United States alone, with half of all men and one-third of all women in the states developing it at some point in their lifetime. The society further explains that the label “cancer” includes over 100 diseases, all having to do with abnormal cell growth in different areas of the body. The good news, however, is that the risk of developing cancer can be decreased by a shift toward healthier eating, more exercise and the avoidance of tobacco and excessive sunlight.
The Role Diet Plays in Preventing Cancer
The importance of diet in preventing cancer has been a hot topic in recent years. It increased to red-hot topic status in 2008 when the International Agency for Research on Cancer released that the prevalence of many cancer types is lower in Japan than it is North America or Western Europe by a ratio of 2-to-10. This led researchers to analyze the Japanese diet and discover why they seem to be fairly protected from alimentary system cancers—colorectal, bladder and prostate—and breast cancer. The answer they found is the soybean.
ScienceDaily revealed that plant scientist Hari B. Krishnan was joined by three colleagues at the University of Missouri to study and pursue a more efficient and affordable way to extract the cancer-fighting properties of the soybean itself. The study began two years ago, and was funded by the Agricultural Research Service of the U.S. Department of Agriculture. According to Krishnan, the substance, called the Bowman-Birk Protease Inhibitor (BBI), is a protein that suppresses the uncontrolled division and growth of cells that leads to the development of cancer. According to the American Journal of Clinical Nutrition, BBI curbs this process, called carcinogenesis, through the inhibition of both trypsin and chymotrypsin, which are enzymes that break down proteins in our digestive systems.
Bowman-Birk Protease Inhibitor: The Soybean’s Cancer Fighting Substance
Originally sparking interest with its discovery in 1963, according to the Gizmag website, BBI has demonstrated powerful chemoprotective and anticancer properties against a host of cancers—breast, colon, liver, lung, esophageal and oral cancers. These studies led the Food and Drug Administration to label BBI as an “Investigational New Drug” in 1992, inspiring various studies and research since. Professor of research oncology at the Biomedical Graduate School at the University of Pennsylvania Dr. Ann R. Kennedy has conducted extensive research on BBI and its effects for several years. According to Kennedy, “all legumes contain relatively high quantities of protease inhibitors like BBI, but soybeans have the highest contents known.” In 1978, Kennedy stated in her first publication on BBI’s anticarcinogenic capabilities that “the soybean-derived protease inhibitor, [BBI], is a potent chymotrypsin inhibitor that has been extensively studied for its ability to prevent carcinogenesis.”
Although BBI is a proven cancer fighter, there may be one drawback to the substance. The American Journal of Clinical Nutrition addresses the concern of the potentially toxic effects of soybean protease inhibitors due to a recent study that found atypical pancreatic growth in rats. The journal states that the rats’ inhibitors may hinder trypsin but not chymotrypsin, leading to abnormal pancreatic growth only in rats and not in humans. Kennedy, however, is not convinced, stating that, “No negative effects have been observed.”
The Process of Extracting BBI from Soybeans
Krishnan reveals that the extraction of BBI involves the use of organic solvents and that “the procedure is time-consuming and uses harsh chemicals.” His discoveries led to a new method of extraction, which he describes as “very simple. By just incubating soybean seeds in warm water, you can obtain sufficient amounts of BBI.” ScienceDaily states more specifically that the soybean seeds incubated in water warmed to 122 degrees Fahrenheit for four hours naturally release large quantities of BBI to be harvested from the water itself. When later examined by Krishnan and his associates, the BBI was able to stop the division of breast cancer cells in a laboratory dish, proving to be highly effective.
While soybeans aid in preventing the onset of cancer, what if a person has already developed a form of the disease? Krishnan stated that so far they have not conducted any studies concerning BBI’s affect on current cancer patients. “However, it will be very interesting to see if BBI obtained by incubating the seeds in warm water can benefit cancer patients,” Krishnan said. “It will require clinical trials and hopefully such studies will be conducted in the future.” Kennedy’s speculations are similar. “I expect it will have some anticarcinogenic activity in people who already have cancer—particularly prostate cancer—but its major activity is in cancer prevention.”
In terms of the BBI extraction process, Krishnan hopes his newly discovered method will be put to good use. “In the future we hope our method can be exploited for the isolation of BBI,” he said. In the meantime, toss some soybeans in a stir-fry or steam them in their pods to enjoy a snack that’s far healthier than we knew.