大豆以及其他豆類中植物來源的化學物質具有廣泛營養(yǎng)學價值，如大豆異黃酮是具有健康保護和治療學意義的非固醇類物質,。由于它能與雌激素受體結合，具有雌激素樣作用,，故稱之為植物雌激素,。
隨著近年研究的深入，人們發(fā)現大豆以及大豆中某些化學物質對多種疾病包括腫瘤,、心血管疾病,、骨質疏松癥和神經退行性疾病等有預防和治療作用，相關研究的興趣也日漸增加,。
其中,，被廣泛認可的是大豆等豆類植物中的化學物質可以減少罹患子宮內膜癌的風險，但迄今為止,，現有的流行病學研究報告結果并不能支持這一觀點,。
美國夏威夷癌癥研究中心和洛杉磯南加州大學的研究人員為了解決這一問題，在一項最新研究中分析了豆科植物,、大豆,、豆腐以及大豆異黃酮的攝入量與絕經婦女罹患子宮內膜癌風險的關系性，研究結果發(fā)表在JNCI雜志上,。
為了分析飲食情況與子宮內膜癌風險之間的關系,，研究人員收集了在1993年8月至1996年8月之間，未進行子宮切除術的46,027例絕經女性的相關資料,?？蒲腥藛T對這些女性平均隨訪13.6年，其中有489名絕經女性確診患有子宮內膜癌,。
該項研究結果表明：罹患子宮內膜癌的風險與總異黃酮攝入量,、大豆攝入量、染料木素的攝入量呈負相關,。那些總異黃酮攝入量≥7.82毫克每1000千卡/天,、大豆攝入量≥3.54毫克每1000千卡/天、染料木素攝入量≥3.40毫克每1000千卡/天的女性罹患子宮內膜癌的風險大大降低,。同時研究證實子宮內膜癌的風險與豆類食物如大豆,、豆腐或是黃豆的攝入量之間沒有統(tǒng)計學意義,。
研究人員最后下結論稱：我們飲食結構中存在含異黃酮的食物或許能防止絕經婦女子宮內膜癌的發(fā)生,。(生物谷 Bioon.com)
doi: 10.1093/jnci/djr475
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Legume, Soy, Tofu, and Isoflavone Intake and Endometrial Cancer Risk in Postmenopausal Women in the Multiethnic Cohort Study
Nicholas J. Ollberding,Unhee Lim,Lynne R. Wilkens,Veronica Wendy Setiawan,Yurii B. Shvetsov,Brian E. Henderson,Laurence N. Kolonel andMarc T. Goodman
Background Phytochemicals found in soy and other legumes have been speculated to reduce the risk of endometrial cancer; however, inconsistent findings have been reported in the few epidemiological studies conducted to date.
Methods We conducted a prospective analysis of 46027 nonhysterectomized postmenopausal women who were recruited into the Multiethnic Cohort (MEC) Study between August 1993 and August 1996 and provided detailed baseline information on diet and other endometrial cancer risk factors. A total of 489 women diagnosed with incident endometrial cancer were identified through the Surveillance, Epidemiology, and End Results tumor registry linkages during a median follow-up period of 13.6 years. Cox proportional hazards models were used to estimate multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with dietary intake of legumes, soy, and tofu, and for total isoflavones and specific isoflavones (daidzein, genistein, or glycitein). Truncated (age 50–89 years) age-adjusted incidence rates were calculated by applying age-specific rates within isoflavone quintiles to the overall MEC population eligible for endometrial cancer. To estimate the percentage of endometrial cancers that may have been prevented by consuming the highest quintile of total isoflavones, the partial population attributable risk percent was calculated.
Results A reduced risk of endometrial cancer was associated with total isoflavone intake (highest vs lowest quintile, ≥7.82 vs <1.59 mg per 1000 kcal/d, RR = 0.66, 95% CI = 0.47 to 0.91), daidzein intake (highest vs lowest quintile, ≥3.54 vs <0.70 mg per 1000 kcal/d, RR = 0.64, 95% CI = 0.46 to 0.90), and genistein intake (highest vs lowest quintile, ≥3.40 vs <0.69 mg per 1000 kcal/d, RR = 0.66, 95% CI = 0.47 to 0.91). No statistically significant association with endometrial cancer risk was observed for increasing intake of legumes, soy, tofu, or glycitein. Truncated age-adjusted incidence rates of endometrial cancer for the highest vs lowest quintile of total isoflavone intake were 55 vs 107 per 100000 women per year, respectively. The partial population attributable risk percent for total isoflavone intake lower than the highest quintile was 26.7% (95% CI = 5.3% to 45.8%).
Conclusion This study suggests that greater consumption of isoflavone-containing foods is associated with a reduced risk of endometrial cancer in this population of nonhysterectomized postmenopausal women.
