Lee Sang-Ah, Shu Xiao-Ou, Li Honglan, Yang Gong, Cai Hui, Wen Wanqing, Ji Bu-Tian, Gao Jing, Gao Yu-Tang, Zheng Wei
Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37203-1738, USA.
Am J Clin Nutr. 2009 Jun;89(6):1920-6. doi: 10.3945/ajcn.2008.27361. Epub 2009 Apr 29.
Soy food is a rich source of isoflavones--a class of phytoestrogens that has both antiestrogenic and anticarcinogenic properties.
The objective was to evaluate the association of adolescent and adult soy food intake with breast cancer risk in a cohort of 73,223 Chinese women who participated in the Shanghai Women's Health Study.
A validated food-frequency questionnaire was used to assess usual dietary intake during adulthood and adolescence. After a mean follow-up of 7.4 y, 592 incident cases of breast cancer were identified for longitudinal analyses by using Cox regressions.
Adult soy food consumption, measured either by soy protein or isoflavone intake, was inversely associated with the risk of premenopausal breast cancer, and the association was highly statistically significant (P for trend < 0.001). The multivariate-adjusted relative risks (RRs) for the upper intake quintile compared with the lowest quintile were 0.41 (95% CI: 0.25, 0.70) for soy protein intake and 0.44 (95% CI: 0.26, 0.73) for isoflavone intake. High intake of soy foods during adolescence was also associated with a reduced risk of premenopausal breast cancer (RR: 0.57; 95% CI: 0.34, 0.97). Women who consumed a high amount of soy foods consistently during adolescence and adulthood had a substantially reduced risk of breast cancer. No significant association with soy food consumption was found for postmenopausal breast cancer.
This large, population-based, prospective cohort study provides strong evidence of a protective effect of soy food intake against premenopausal breast cancer.
大豆食品是异黄酮的丰富来源，异黄酮是一类具有抗雌激素和抗癌特性的植物雌激素。
在参与上海女性健康研究的73223名中国女性队列中，评估青少年和成年期大豆食品摄入量与乳腺癌风险之间的关联。
使用经过验证的食物频率问卷评估成年期和青少年期的日常饮食摄入量。经过平均7.4年的随访，通过Cox回归确定了592例乳腺癌发病病例用于纵向分析。
以大豆蛋白或异黄酮摄入量衡量的成年期大豆食品消费与绝经前乳腺癌风险呈负相关，且该关联具有高度统计学意义（趋势P<0.001）。与最低五分位数相比，最高摄入量五分位数的多变量调整相对风险（RR）对于大豆蛋白摄入量为0.41（95%CI：0.25，0.70），对于异黄酮摄入量为0.44（95%CI：0.26，0.73）。青少年期高摄入大豆食品也与绝经前乳腺癌风险降低相关（RR：0.57；95%CI：0.34，0.97）。在青少年期和成年期持续大量摄入大豆食品的女性患乳腺癌的风险大幅降低。未发现与绝经后乳腺癌的大豆食品消费有显著关联。
这项基于人群的大型前瞻性队列研究提供了强有力的证据，证明摄入大豆食品对绝经前乳腺癌具有保护作用。
