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.
Feeding mice genistein, an antioxidant found in soy, decreased metastasis of prostate cancer to the lungs by 96 percent compared with mice that were not fed genistein. According to the study’s researchers the amount of genistein that was
fed to the mice was no higher than what a human would eat in a soybean-rich diet.
“These impressive results give us hope that genistein might show
some effect in preventing the spread of prostate cancer in
patients,” said the study’s senior investigator, Raymond C. Bergan,
MD, director of experimental therapeutics for the Robert H. Lurie
Comprehensive Cancer Center of Northwestern University.
“Diet can affect cancer and it doesn’t do it by magic,” Bergan
said. “Certain chemicals have beneficial effects and now we have all
the preclinical studies we need to suggest genistein might be a very
promising chemopreventive drug.”
Prior to this study Bergan had demonstrated in prostate cancer
cell cultures that genistein inhibited the detachment of cancer cells
from a primary prostate tumor. Genisten blocks the activation of certain molecules which regulate protein pathways. These pathways loosen cancer cells
from a tumor and push them to migrate to distant sites .”When genisten is introduced into a cell culture, you can actually see cells flatten themselves in order to spread out and adhere to nearby cells,” said Bergen.
This study, which was done at Northwestern University, was the first to find that genistein can stop prostate cancer metastasis in a living organism.
Genistein did not reduce the size of tumors in the prostate, but it did stop lung
metastasis almost completely. The experiment was replicated and found
the same result.
Epidemiologic studies have shown that men who eat soy are at reduced risk of prostate cancer death. However, these results are associative and do not prove any causation. However, this study strongly points the way for a quick start of a clinical trial to see if these results will hold up in humans and if there is a causative relationship between inhibiting prostate cancer tumor cell migration and genisten.
In the mean time increasing your soy consumption might not be a bad idea.
Joel T Nowak MA, MSW
My husband has advanced prostate cancer – diagnosed four years ago. He is on Lupron and the cancer is in remission. He takes a soy shake daily (with blueberries, flax seed and sometimes strawberries, yogurt, bananas.) My question is this – your article says that genistein may slow down metastasis (his shake has genistein), but I have also heard that although soy may be beneficial in preventing prostate cancer, once it sets in and becomes advanced, it may promote the cancer. Please advise. And would the benefit from genistein (slowing down of metastasis to the lungs) extend to other organs, bones, and lymph nodes?
Thank you.
Martha- The study I referred to was a mouse study, you should not automatically assume that it will be replicable in people. Mouse models are used in research because of ethical issues surrounding human experimentation. Once a theory can be demonstrated in mice, if there are not safety issues, it is possible to move to human subjects.
This study, using mice, only showed that genistein reduced prostate metastasis by preventing the detachment of cancer cells from the tumor. It says nothing about prostate cancer prevention, treating existing prostate cancer or making prostate cancer more aggressive.
Most people accept the fact that diet does have an effect on cancer, but there isn’t always a lot of agreement on specifics. There are a lot of theories, but many of them are not evidence based. This does not mean that they are not real, it just means there is not scientific proof.
Studies like this one reflect the steps we need to verify our theories.
My own personal theory- For all cancers the simplest way to go – Eat a heart healthy diet. Increasing items like genistein will not have an adverse affect and might very well have a positive affect. So tell your husband to enjoy his shake.
Joel
Thank you very much for your response. And your website.
Regards,
Martha
I have localized Prostate Cancer which was diagnosed in March of 2006. I am currently having biopsies done every 1 1/2 yrs.
I would be interested in knowing if someone could tell me where I can locate this SOY SHAKE…or is it something I have to make myself. I get vitamins and herbs from a Vitamin Shoppe for another condition, so I am wondering if the Shake can be purchased there.
Thank You and any information you can give me would be appreciated.