Plasma equol concentration is not associated with breast cancer and fibrocystic breast conditions among women in Shanghai, China

卷:36

Atkinson, Charlotte ; Ray, Roberta M. ; Li, Wenjin ; Lin, Ming-Gang ; Gao, Dao Li ; Shannon, Jackilen ; Stalsberg, Helge ; Porter, Peggy L. ; Frankenfeld, Cara L. ; Wahala, Kristiina ; Thomas, David B. ; Lampe, Johanna W.

Level 3 Univ Hosp Bristol Educ Ctr

关键词: Breast cancer;    Daidzein;    Equol;    Fibrocystic changes in the breast;    Isoflavone;    Nested case-control study;    Women;   

DOI  :  10.1016/j.nutres.2016.03.008

学科分类：食品科学和技术

【 摘 要 】

Equol (a bacterial metabolite of the soy isoflavone daidzein) is produced by 30% to 50% of humans and may be associated with health outcomes. We hypothesized that plasma equol would be inversely associated with risks of fibrocystic breast conditions (FBC) and breast cancer (BC). Plasma from women in a breast self-examination trial in Shanghai with BC (n = 269) or FBC (n = 443), and age-matched controls (n = 1027) was analyzed for isoflavones. Equol was grouped into categories (<20, 20-<45, and >= 45 nmol/L) and, among women with daidzein >= 20 nmol/L, the log(10) equol:daidzein ratio was grouped into tertiles. Where available, non-cancerous tissue (NCT) adjacent to the carcinomas from women with BC were classified as non-proliferative or proliferative (n = 130 and 172, respectively). The lesions from women with FBC were similarly classified (n = 99 and 92, respectively). Odds ratios (OR) and 95% confidence intervals (CI) were calculated across equol categories and tertiles of log(10) equol:daidzein ratio. Equol categories were not associated with FBC or BC >.05). For log(10) equol:daidzein, compared to controls there were positive associations in the mid tertile for proliferative FBC (OR 2.06, 95% CI 1.08-3.93), BC with proliferative NCT (OR 2.95, 95% CI 1.37-6.35), and all BC regardless of histology (OR 2.37, 95% CI 1.43-3.95). However, trends in ORs with increasing plasma equol values or equol:daidzein ratios were not observed (P >.05). The results of this study do not provide evidence that equol plays a role in the etiology of these breast conditions. However, further work is needed to confirm or refute this conclusion. (C) 2016 Elsevier Inc. All rights reserved.