Wu Anna H, Wan Peggy, Hankin Jean, Tseng Chiu-Chen, Yu Mimi C, Pike Malcolm C
Department of Preventive Medicine, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA.
Carcinogenesis. 2002 Sep;23(9):1491-6. doi: 10.1093/carcin/23.9.1491.
The association between soyfood intake and breast cancer risk is controversial. Most of the epidemiologic studies published on this topic in the 1990s were not designed to specifically address this question. We conducted a population-based, case-control study of breast cancer among Chinese, Japanese and Filipino women in Los Angeles County to further investigate the role of soy. Our primary objective was to quantify breast cancer risks associated with intake of soy during adolescence and adult life among Asian-American women. During 1995-1998, we successfully interviewed 501 breast cancer patients and 594 control subjects. Intake of soy among Asian-Americans is still relatively high; the median intake was 12 mg isoflavones/day, approximately one-third of that reported in a recent study in Shanghai, China. The risk of breast cancer was significantly inversely associated with soy intake during adolescence and adult life. After adjusting for age, specific Asian ethnicity, education, migration history and menstrual and reproductive factors, women who reported soy intake at least once per week during adolescence showed a statistically significantly reduced risk of breast cancer. There was also a significant trend of decreasing risk with increasing soy intake during adult life. When we considered soy intake during both adolescence and adult life, subjects who were high-soy consumers during both time periods showed the lowest risk (OR=0.53, 95% CI=0.36-0.78) compared with those who were low consumers during both time periods. Risk of breast cancer was intermediate among subjects who were high-soy consumers during adolescence and low-soy consumers during adult life (OR=0.77, 95% CI=0.51-1.10). Based on a relatively small number of subjects, the risk did not appear to differ between those who were low consumers during adolescence and high consumers during adult life. Results remained similar after adjustment for other potential confounders including other dietary and non-dietary risk factors for breast cancer. These results show that high soy intake in childhood in Asian-Americans is associated with reduced breast cancer risk. Risk may be further reduced by intake as an adult.
大豆食品摄入量与乳腺癌风险之间的关联存在争议。20世纪90年代发表的关于这一主题的大多数流行病学研究并非专门针对这个问题设计的。我们在洛杉矶县对中国、日本和菲律宾女性进行了一项基于人群的乳腺癌病例对照研究，以进一步探究大豆的作用。我们的主要目标是量化亚裔美国女性在青春期和成年期摄入大豆与乳腺癌风险之间的关系。1995年至1998年期间，我们成功采访了501名乳腺癌患者和594名对照对象。亚裔美国人的大豆摄入量仍然相对较高；中位数摄入量为12毫克异黄酮/天，约为中国上海最近一项研究报告摄入量的三分之一。乳腺癌风险与青春期和成年期的大豆摄入量显著负相关。在调整了年龄、特定亚裔种族、教育程度、移民史以及月经和生殖因素后，报告在青春期每周至少摄入一次大豆的女性患乳腺癌的风险在统计学上显著降低。在成年期，随着大豆摄入量增加，风险也有显著降低的趋势。当我们考虑青春期和成年期的大豆摄入量时，在两个时期都是高大豆摄入量的受试者风险最低（OR = 0.53，95% CI = 0.36 - 0.78），而在两个时期都是低摄入量的受试者风险最高。在青春期是高大豆摄入量而成年期是低摄入量的受试者中，乳腺癌风险处于中间水平（OR = 0.77，95% CI = 0.51 - 1.10）。基于相对较少的受试者数量，在青春期是低摄入量而成年期是高摄入量的受试者与在青春期是高摄入量而成年期是低摄入量的受试者之间，风险似乎没有差异。在调整了包括其他乳腺癌饮食和非饮食风险因素在内的其他潜在混杂因素后，结果仍然相似。这些结果表明，亚裔美国人儿童期高大豆摄入量与降低乳腺癌风险有关。成年期摄入大豆可能会进一步降低风险。
