Wu A H, Ziegler R G, Horn-Ross P L, Nomura A M, West D W, Kolonel L N, Rosenthal J F, Hoover R N, Pike M C
Department of Preventive Medicine, University of Southern California, Los Angeles 90033-0800, USA.
Cancer Epidemiol Biomarkers Prev. 1996 Nov;5(11):901-6.
Breast cancer rates among Asian-Americans are lower than those of US whites but considerably higher than rates prevailing in Asia. It is suspected that migration to the US brings about a change in endocrine function among Asian women, although reasons for this change remain obscure. The high intake of soy in Asia and its reduced intake among Asian-Americans has been suggested to partly explain the increase of breast cancer rates in Asian-Americans. We conducted a population-based case-control study of breast cancer among Chinese-, Japanese-, and Filipino-American women in Los Angeles County MSA, San Francisco Oakland MSA, and Oahu, Hawaii. Using a common questionnaire which assessed frequency of intake of some 90 food items, 597 Asian-American women (70% of those eligible) diagnosed with incident, primary breast cancer during 1983-1987 and 966 population-based controls (75% of those eligible) were interviewed. Controls were matched to cases on age, ethnicity, and area of residence. This analysis compares usual adult intake of soy (estimated primarily from tofu intake) among breast cancer cases and control women. After adjustment for age, ethnicity and study area, intake of tofu was more than twice as high among Asian-American women born in Asia (62 times per year) compared to those born in the US (30 times per year). Among migrants, intake of tofu decreased with years of residence in the US. Risk of breast cancer decreased with increasing frequency of intake of tofu after adjustment for age, study area, ethnicity, and migration history; the adjusted OR associated with each additional serving per week was 0.85 (95% CI = 0.74-0.99). The protective effect of high tofu intake was observed in pre- and postmenopausal women. This association remained after adjustment for selected dietary factors and menstrual and reproductive factors. However, this study was not designed specifically to investigate the role of soy intake and our assessment of soy intake may be incomplete. We cannot discount the possibility that soy intake is a marker of other protective aspects of Asian diet and/or Asian lifestyle.
亚裔美国人的乳腺癌发病率低于美国白人，但远高于亚洲地区的普遍发病率。尽管这种变化的原因尚不清楚，但据推测，移民到美国会导致亚洲女性内分泌功能发生变化。有人认为，亚洲人大豆摄入量高，而亚裔美国人大豆摄入量减少，这在一定程度上解释了亚裔美国人乳腺癌发病率的上升。我们在洛杉矶县都会统计区、旧金山奥克兰都会统计区和夏威夷瓦胡岛，对华裔、日裔和菲律宾裔美国女性进行了一项基于人群的乳腺癌病例对照研究。通过一份通用问卷评估了约90种食物的摄入频率，对1983 - 1987年间确诊为原发性乳腺癌的597名亚裔美国女性（占符合条件者的70%）和966名基于人群的对照者（占符合条件者的75%）进行了访谈。对照者在年龄、种族和居住地区方面与病例进行匹配。本分析比较了乳腺癌病例和对照女性中大豆的通常成人摄入量（主要根据豆腐摄入量估算）。在对年龄、种族和研究地区进行调整后，出生在亚洲的亚裔美国女性豆腐摄入量（每年62次）是出生在美国的女性（每年30次）的两倍多。在移民中，豆腐摄入量随着在美国居住年限的增加而减少。在对年龄、研究地区、种族和移民史进行调整后，乳腺癌风险随着豆腐摄入频率的增加而降低；每周每增加一份豆腐的调整后比值比为0.85（95%可信区间 = 0.74 - 0.99）。在绝经前和绝经后女性中均观察到高豆腐摄入量的保护作用。在对选定的饮食因素以及月经和生殖因素进行调整后，这种关联仍然存在。然而，本研究并非专门设计用于调查大豆摄入的作用，而且我们对大豆摄入的评估可能并不完整。我们不能排除大豆摄入是亚洲饮食和/或亚洲生活方式其他保护方面的一个标志的可能性。
