Controversy surrounds the supplementation with Soy. A great number of studies have shown that soy, inhibit breast cancer in laboratory studies. However, associations between consumption of soy-containing foods and breast cancer risk have been inconsistent in epidemiologic studies. What is known is that soy supplementation alters expression of genes associated with breast cancer. This may raise concerns that soy could have adverse effects in breast cancer, according to a new study published September 4, 2014 edition of JNCI, the Journal of the National Cancer Institute.[1][2]
The impact of soy consumption on breast cancer prevention and treatment is not clear although many women believe soy supplementation is beneficial based primarily on results from epidemiological studies. Moshe Shike, M.D., from the Department of Medicine at Memorial Sloan-Kettering Cancer Center and Weill Cornell Medical College in New York, NY, and colleagues conducted a randomized placebo-controlled study of the effects of soy supplementation on gene expression and markers of breast cancer risk among women diagnosed with invasive breast cancer.
…this data raise concern that soy may exert a stimulating effect on breast cancer in a subset of women…
Clinical trial
The study, run between 2003 and 2007 at Memorial Sloan-Kettering, enrolled a total of 140 patients who were randomized to either supplementation with a soy protein or with a placebo with a milk protein, which lasted from the initial surgical consultation to the day before surgery (range=7-30 days). Tumor tissues from the diagnostic biopsy (pre-treatment) and at the time of resection (post-treatment) were then analyzed. They observed changes in several genes that promote cell cycle progression and cell proliferation among women in the soy group.
In the article, the authors conclude that this data raise concern that soy may exert a stimulating effect on breast cancer in a subset of women.
Timing is critical
In an accompanying editorial, V. Craig Jordan, O.B.E., D.Sc., Ph.D., FMedSci, from the Department of Oncology at the Georgetown University Lombardi Comprehensive Cancer Center, Washington, DC, discusses how timing of soy supplementation is critical and reviews the evidence in the literature on phytoestrogens, which are contained in soy, and their known action in breast cancer.[3]
Jordan says that this new study “?illustrates the dangers of phytoestrogen consumption too soon, around menopause, but the biology of estrogen in estrogen-deprived conditions suggests that phytoestrogen could have benefit a decade after menopause.” He cautions that appropriate doses of soy and timing of consumption are critical considerations.
For more information:
[1] Yamamoto S, Sobue T, Kobayashi M, Sasaki S, Tsugane S. Soy, isoflavones, and breast cancer risk in Japan. J Natl Cancer Inst. 2003 Jun 18;95(12):906-13.[Article][PubMed]
[2]Shike M, Doane AS, Russo L, Cabal R, Reis-Filo J, Gerald W, Cody H, Khanin R, Bromberg J, Norton L. The effects of soy supplementation on gene expression in breast cancer: a randomized placebo-controlled study. J Natl Cancer Inst. 2014 Sep 4;106(9). pii: dju189. doi: 10.1093/jnci/dju189[Article][PubMed]
[2] Jordan VC. Avoiding the bad and enhancing the good of soy supplements in breast cancer. J Natl Cancer Inst. 2014 Sep 4;106(9). pii: dju233. doi: 10.1093/jnci/dju233.[Article][PubMed]
Copyright ? 2014 Sunvalley Communication. All rights reserved. Republication or redistribution of Sunvalley Communication content, including by framing or similar means, is expressly prohibited without the prior written consent of Sunvalley Communication. Sunvalley Communication shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Onco’Zine and Oncozine are registered trademarks and trademarks of Sunvalley Communication around the world.
