我們所吃的某些食物中或許有還未發(fā)現(xiàn)的具有抗癌作用的化合物,。大豆異黃酮是大豆中主要成分,，近年來研究表明該化合物具有抗雌激素活性,，發(fā)揮抗腫瘤作用。
但最新,，發(fā)表在由美國癌癥研究協(xié)會出版的雜志Cancer Prev Res上的一篇研究論文證實：大豆中主要黃酮類物質(zhì)--大豆異黃酮并不能抑制乳腺癌細胞的增殖,。
在由西北大學(xué)Robert H. Lurie研究中心的外科醫(yī)生--Seema A. Khan, M.D帶領(lǐng)開展的這項隨機臨床試驗中，研究人員隨機給98名女性乳腺癌患者服用混合型大豆異黃酮補充劑或是安慰劑,。
98名乳腺癌患者在服用大豆異黃酮或是安慰劑6個月后,，研究者檢測了患者體內(nèi)一種被證實是癌細胞生長的蛋白標志物--Ki-67的水平。
結(jié)果發(fā)現(xiàn)：服用大豆異黃酮的乳腺癌患者與服用安慰劑的乳腺癌患者體內(nèi)Ki-67的水平并沒有差異,。但未絕經(jīng)的乳腺癌女性患者體內(nèi),， Ki-67的水平從1.71增加到了2.18，這一結(jié)果提示了大豆異黃酮補充劑有可能存在陰性作用,，即有可能促進腫瘤細胞的生長,。
研究人員表示：雖然大豆異黃酮主要來之于大豆食物中，但這并不表示我們食用大豆能帶來類似大豆異黃酮補充劑的功效,。并且使用大豆異黃酮補充劑能否抑制乳腺癌細胞的增殖仍沒有定論,。(生物谷 Bioon.com)
doi:10.1158/1940-6207.CAPR-11-0251
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Soy Isoflavone Supplementation for Breast Cancer Risk Reduction: A Randomized Phase II Trial
Seema A. Khan1, Robert T. Chatterton2, Nancy Michel4, Michelle Bryk1, Oukseub Lee1, David Ivancic1, Richard Heinz1, et al.
Soy isoflavone consumption may protect against breast cancer development. We conducted a phase IIB trial of soy isoflavone supplementation to examine its effect on breast epithelial proliferation and other biomarkers in the healthy high-risk breast. One hundred and twenty-six consented women underwent a random fine-needle aspiration (rFNA); those with 4,000 or more epithelial cells were randomized to a double-blind 6-month intervention of mixed soy isoflavones (PTIG-2535) or placebo, followed by repeat rFNA. Cells were examined for Ki-67 labeling index and atypia. Expression of 28 genes related to proliferation, apoptosis, and estrogenic effect was measured using quantitative reverse transcriptase PCR. Hormone and protein levels were measured in nipple aspirate fluid (NAF). All statistical tests were two-sided. Ninety-eight women were evaluable for Ki-67 labeling index. In 49 treated women, the median Ki-67 labeling index was 1.18 at entry and 1.12 post intervention, whereas in 49 placebo subjects, it was 0.97 and 0.92 (P for between-group change: 0.32). Menopausal stratification yielded similar results between groups, but within premenopausal soy-treated women, Ki-67 labeling index increased from 1.71 to 2.18 (P = 0.04). We saw no treatment effect on cytologic atypia or NAF parameters. There were significant increases in the expression of 14 of 28 genes within the soy, but not the control group, without significant between-group differences. Plasma genistein values showed excellent compliance. A 6-month intervention of mixed soy isoflavones in healthy, high-risk adult Western women did not reduce breast epithelial proliferation, suggesting a lack of efficacy for breast cancer prevention and a possible adverse effect in premenopausal women.
