In the Pink Month or National Breast Cancer Awareness Month, the following is intended for breast cancer survivors.
A study published in Journal of American Medical Association suggests use of soy foods may help women diagnosed with breast cancer reduce risk of premature death and recurrence.
The study led by Shu X.O. and colleagues from Vanderbilt Epidemiology Center showed those who had highest intake of soy protein were 30 percent less likely to die or had recurrence of the disease during a 4-year follow-up.
Soy foods are high in isoflavones, phytoestrogens that have been associated with reduced risk of breast cancer in previous studies, according to the background information in the study report.
The study was meant to examine the effect of soy protein intake on the health in women who have already been diagnosed with breast cancer.
For the study, the researchers enlisted 5,042 female breast cancer survivors in China ages 20 to 75 years who participated in the Shanghai Breast Cancer Survival Study. The participants were diagnosed with the disease between March 2002 and April 2006 and followed up through June 2009.
During the 3.9-year follow-up, of 5,033 women who underwent surgery, 444 women died and 534 suffered recurrence or breast cancer related deaths.
The researchers found those who had highest intake of soy protein were 29 percent less likely to die and 32 percent less likely to have recurrence of breast cancer compared to those who had lowest intake.
The mortality rate among women having the highest intake of soy protein was 7.4 percent compared to 10.3 percent for those who had lowest intake.
The recurrence rate among those who ate highest amounts of soy foods was 8 percent compared to 11.2 percent among those who had the lowest intake.
The researchers concluded “Among women with breast cancer, soy food consumption was significantly associated with decreased risk of death and recurrence.”
More reports on diet and breast cancer will be released in the pink month.
New studies indicate that breast cancer survival rate may be increased with moderate soy consumption
Eating soy boosts breast cancer survival
Soy consumption for cancer patients has been the subject of some controversy. A new study has shown that breast cancer survivors who consume soy foods reap important health benefits and found that eating soy can increase the rate of survival for breast cancer patients.
According to a recent report published in the Journal of the American Medical Association (JAMA), women diagnosed with breast cancer and who consumed soy foods, such as tofu, soy milk, or edamame reduced their risk of recurrence by 32 percent. 1
Previous research refuted
Previous research had produced contradictory results with some studies suggesting that soy foods reduce the risk of breast cancer and others that compounds unique to soy may help breast cancer cells to grow. Now, previous theories been refuted with this new study demonstrating that soy does not increase the growth of breast cancer cells and has been proven to increase survival rates.
Higher soy intake – lower mortality
Researchers also found that breast cancer patients who consumed soy had a 29 percent decreased risk of death, compared to women who consumed little or no soy. Xiao Ou Shu, MD, PhD, lead researcher and professor of medicine at Vanderbilt University Medical Center in Nashville, TN, said, “Women who had a higher soy intake had a lower mortality and lower risk of relapse [than women with a low soy intake].”
Dr. Shu and her fellow researchers analyzed data from the Shanghai Breast Cancer Survival Study, the largest population-based study of breast cancer survival to date. The study included 5,042 women from 20 to 75 years of age and followed them for a period of four years.
Soy compounds reduce estrogen in the body
Soybeans are rich in phytoestrogens, also known as isoflavones. Although these substances are one thousand times less potent than human estrogen, there has been some concern that isoflavones may have an estrogen-like effect and may increase cancer risk.
However, many experts believe that because isoflavones fool the body into accepting the very weak compound, phytoestrogen actually competes with the human estrogen, thus reducing the overall level of estrogen in the body.
Soy is safe and potentially beneficial
An editorial accompanying this new study suggests some probable inconsistencies in prior research. The editorial attributed those inconsistencies to the fact that soy consumption in the U.S. is a good deal lower, which made the beneficial effects of consuming soy foods difficult to identify. In China, soy intake is higher and diets tend to include the intake of more traditional soy from food sources, rather than from soy supplements.
The researchers report, “The inverse association was evident among women with either estrogen receptor-positive or receptor-negative breast cancer and was present in both users and nonusers of tamoxifen.”
“In summary, in this population-based prospective study, we found that soy food intake is safe and was associated with lower mortality and recurrence among breast cancer patients.” These scientists concluded that, among women with breast cancer, soy food consumption was significantly associated with decreased risk of death and recurrence. Dr Shu and her colleagues stated, “This study suggests that moderate soy food intake is safe and potentially beneficial for women with breast cancer.”
1. Shu XO, Zheng Y, Cai H, et al. Soy food intake and breast cancer survival. JAMA. 2009;302:2437-2443. Ballard-Barbash R, Neuhouser ML. Challenges in design and interpretation of observational research on health behaviors and cancer survival. JAMA. 2009;302:2483-2484.
A new study finds that the isoflavone in soybeans can prevent a second stroke in individuals suffering from cerebrovascular events. According to the study published in The European Heart Journal, isoflavone reverses endothelial dysfunction in stroke sufferers.
Similar to cholesterol-lowering drugs, the chemical, also known as a phytoestrogen due to its estrogen-like effects, can improve the arterial blood flow in patients with a positive stroke history. Previous studies had reported that soy-rich diets can lower blood cholesterol levels and help prevent breast and prostate cancers. Isoflavones are also effective in lowering the risk of arteriosclerosis and other cardiovascular events.
University of Hong Kong scientists concluded that taking isoflavone dietary supplements can help reduce the risk of future strokes or cardiovascular events in stroke patients.
Literature Review Finds No Indication that Soy Decreases Testosterone Levels
ST LOUIS, July 20 /PRNewswire/ — A new study published by the American Society for Reproductive Medicine finds that soyfoods and soy isoflavone supplements have no significant effect on male reproductive hormone levels in men. The literature review indicates that soy does not decrease testosterone levels.
Led by Jill M. Hamilton-Reeves, PhD, RD, of St. Catherine’s University, St. Paul, Minnesota, researchers assessed the effects of soy protein and soy isoflavones on measurements of male reproductive hormones. Findings, just published online in Fertility and Sterility, a publication of the American Society for Reproductive Medicine, demonstrate no significant effect of soy protein or soy isoflavone intake on circulating levels of testosterone, sex hormone-binding globulin or free testosterone in men.
The comprehensive meta-analysis examined the existing scientific literature including all clinical studies examining soy’s effect on male reproductive hormones published before July 1, 2008. Fifteen placebo-controlled treatment groups with baseline and ending measures were analyzed. Thirty-two reports involving 36 treatment groups were also assessed in simpler statistical models. Studies published after July 1, 2008, which were not included in the meta-analysis, support the conclusions of the meta-analysis.
Reproductive endocrinologist William R. Phipps, MD, of the University of Rochester Medical Center, a co-author of the analysis stated, “As a high-quality source of protein that is relatively low in saturated fat, soy can be an important part of a heart-healthy diet and may contribute to a decreased risk of coronary heart disease.” He noted that some men have been reluctant to consume soyfoods due to concerns about estrogen-like effects of soy isoflavones, often referred to as phytoestrogens. But according to Phipps, “it is important for the public to understand that there is no clinical evidence to support these ideas. After conducting a comprehensive review of the existing literature, we found no indication that soy significantly alters male sex hormone levels.”
Men can benefit from soyfood consumption as a means to meet daily protein requirements and at the same time possibly also reducing their risk of heart disease.
Citing the research study, Lisa Kelly, MPH, RD, of the United Soybean Board, added,
“Soy is often praised for the positive role it can play in the diets of women. But, years of clinical research have shown that men stand to benefit from soy, too. I encourage men to incorporate soyfoods into a balanced and varied diet and talk to their healthcare provider about their own unique nutritional needs.”
SOURCE: United Soybean Board
ScienceDaily (Mar. 17, 2008) â€” A compound found in soybeans almost completely prevented the spread of human prostate cancer in mice, according to a study published in the March 15 issue of Cancer Research, a journal of the American Association for Cancer Research.
Researchers say that the amount of the chemical, an antioxidant known as genistein, used in the experiments was no higher than what a human would eat in a soybean-rich diet.
Investigators from Northwestern University found that genistein decreased metastasis of prostate cancer to the lungs by 96 percent compared with mice that did not eat the compound in their chowÂ â€” making the study the first to demonstrate genistein can stop prostate cancer metastasis in a living organism.
â€œThese impressive results give us hope that genistein might show some effect in preventing the spread of prostate cancer in patients,â€ said the studyâ€™s senior investigator, Raymond C. Bergan, MD, director of experimental therapeutics for the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
â€œDiet can affect cancer and it doesnâ€™t do it by magic,â€ Bergan said. â€œCertain chemicals have beneficial effects and now we have all the preclinical studies we need to suggest genistein might be a very promising chemopreventive drug.â€
Bergan and his team have previously demonstrated in prostate cancer cell cultures that genistein inhibits detachment of cancer cells from a primary prostate tumor and represses cell invasion. It does this by blocking activation of p38 MAP kinases, molecules which regulate pathways that activate proteins that loosen cancer cells from their tight hold within a tumor, pushing them to migrate. â€œIn culture, you can actually see that when genistein is introduced, cells flatten themselves in order to spread out and stick strongly to nearby cells,â€ he said.
In this study, investigators fed genistein to several groups of mice before implanting them with an aggressive form of prostate cancer. The amount of genistein in the blood of the animals was comparable to human blood concentrations after consumption of soy foods, Bergan said.
The researchers found that while genistein didnâ€™t reduce the size of tumors that developed within the prostate, it stopped lung metastasis almost completely. They repeated the experiment and found the same result.
They then examined tissue in the animals, measuring the size of tumor cellsâ€™ nuclei to determine if the cells had flattened out in order to spread. â€œWithin a tumor, it is hard to tell where the borders of cells stop, so one way to measure adherence is to look at the size of the nuclei in cells and see if they are wider due to cell spread,â€ Bergan said. â€œAnd that is what we found, demonstrating that the drug is having a primary effect on metastasis.â€
He said that the study also found that mice fed genistein expressed higher levels of genes that are involved in cancer cell migration which, Bergan says, at first might not make sense in light of the studyâ€™s conclusion that genistein almost completely blocked metastasis.
â€œWhat we think is happening here is that the cells we put in the mice normally like to move. When genistein restricted their ability to do so, they tried to compensate by producing more protein involved in migration. But genistein prevented those proteins from being activated,â€ he said. â€œThis is really a lesson for researchers who depend on biomarker studies to test whether a treatment is working. They need to be aware that those biomarkers might be telling only half of the story.â€
Bergan cautioned that much is unknown about use of genistein in preventing cancer spread. For example, it may be that the effects of the compound in people who have eaten soy all their lives is stronger than benefit seen in patients who have only started to use genistein.
â€œThe problem we have faced is that epidemiology studies that found men who eat soy are at reduced risk of prostate cancer death are all associative. They donâ€™t prove anything,â€ he said. â€œThe only way we will find out how promising genistein is will be from conducting clinical trials.â€
The FDA claims having 25 grams of soy protein a day, as part of a low-in-saturated-fat and cholesterol diet reduces heart disease risk.
Family: N.O. Fabaceae
Synonym: Coumestrol, daidzein, edamame, frijol de soya, genistein, greater bean, shoyu, soja, sojabohne, soybean
Habitat: The soybean is native to Southeastern Asia.
Soybean, classified as oilseeds, is an annual plant that does not grow more than five feet tall.
Part Used Medicinally:
Soybeans contain all the essential amino acids the body requires and is therefore a complete source of protein. Soybeans do not have any cholesterol, and are high in fiber. They have many vitamins, minerals, and phytochemical compounds (isoflavones). They are a rich source of calcium, iron, zinc, phosphorus, magnesium, B-vitamins, omega 3 fatty acids and fiber. Soybean oil is one of the few common vegetable oils that contain significant amount of aLNA and omega-6 fatty acids.
While the soybean’s high isoflavones, genistein and daidzein content prevents cancer, some consider it as the cause for thyroid and reproductive health problems. Isoflavones, with their estrogen-like properties, alleviate certain menopausal (hot flashes) and PMS symptoms. They also have favorable effects on cognitive function, particularly verbal memory and bone mineral density in postmenopausal women. Isoflavones are good for pre-menopausal women with cyclical breast pain and protect the body from hormone-related cancers. Soybean-rich diets can reduce testosterone levels in men. It is believed to be effective in preventing prostate cancer. Soy proteins provide antioxidants, reduce artery clogging plaques, improve blood pressure, boost the immune system, and lower the risk of atherosclerosis. Soy proteins lower LDL (bad cholesterol) and decrease blood clotting (thrombosis), which reduces the risk of heart attack and strokes. Their effect on HDL (good cholesterol) has not been proven. Soybeans are effective in treating gallbladder stones and Crohn’s disease. Their soluble fiber protects the body from cancers, such as colon and rectal malignancies. Soy proteins and soluble fibers help regulate glucose levels and kidney filtration especially in nephrotic syndrome. Soy is also effective in lowering blood pressure and sugar levels in individuals suffering from type 2 diabetes.
Natural soy milk contains about the same amount of protein as cow’s milk. Most commercially available soy milk is enriched with vitamins especially B12. Unlike cow’s milk it has little saturated fat and no cholesterol or casein, which many consider to be a benefit. It is also a rich source of lecithin and vitamin E.
Soy products contain sucrose as the basic disaccharide instead of galactose, it can safely replace breast milk in children with Galactosemia or in lactose-intolerant individuals. It is high in isoflavones, organic chemicals, polyunsaturated and monounsaturated fats which are good for the heart.
- Soy is traditionally considered to be safe during pregnancy and breastfeeding.
- Like milk, eggs, peanuts, fish, and wheat soy can also act as an allergen.
- While some studies claim soy protects against breast cancer, others show the estrogen-like effects of isoflavones may be harmful for women with breast cancer.
- Soy phytoestrogens disrupt endocrine function and have the potential to cause infertility, hypothyroidism and thyroid cancer.
- Soy formula has been linked to autoimmune thyroid disease in infants.
- Trypsin inhibitors in soy interfere with protein digestion and may cause pancreatic disorders.
- Soy-rich foods increase the body’s vitamin D requirement.