학술논문

Plasma isoflavone levels versus self-reported soy isoflavone levels in Asian-American women in Los Angeles County
Document Type
article
Source
Carcinogenesis. 25(1)
Subject
Biomedical and Clinical Sciences
Oncology and Carcinogenesis
Complementary and Integrative Health
Prevention
Cancer
Nutrition
Clinical Research
Breast Cancer
Adult
Aged
Asian
Breast Neoplasms
Case-Control Studies
China
Female
Genistein
Humans
Isoflavones
Japan
Middle Aged
Philippines
Soybeans
Oncology & Carcinogenesis
Oncology and carcinogenesis
Language
Abstract
In a case-control study conducted among Asian-American women in Los Angeles County, we reported that the risk of breast cancer was significantly reduced in association with soy intake [Wu,A.H., Wan,P., Hankin,J. et al. (2002) Carcinogenesis, 23, 1491-1496]. In a subset of cases (n = 97) and controls (n = 97) we investigated the relationship between self-reported usual adult intake of soy isoflavones which was determined from a food frequency questionnaire and levels of plasma isoflavones (genistein and daidzein) and isoflavone metabolites (equol, dihydrogenistein and dihydrodaidzein) from a randomly timed blood specimen. In analyses conducted in cases and controls separately, levels of plasma genistein, daidzein and total isoflavones increased with increasing levels of self-reported intake of soy isoflavones. Breast cancer cases and control subjects did not differ in their respective associations between total plasma isoflavone levels and self-reported intake (P = 0.48). Among all subjects, there was a 3-fold difference in geometric mean plasma levels of total isoflavones [81.8 (95% CI = 53.4, 125.1) versus 26.4 nmol/l (95% CI = 16.6, 41.8)] between women in the highest quartile of soy isoflavone intake (>12.68 mg isoflavones/1000 kcal) compared with those in the lowest quartile of intake (