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The specific role of isoflavones on estrogen metabolism in premenopausal women

Kumar NB, Cantor A, Allen K, Riccardi D, Cox CE

Cancer, 2002

14 participants · 78 citations

Abstract

Background: There is increasing evidence that dietary factors may play a role in the production, metabolism, and bioavailability of sex hormones and their impact on target tissues. The specific objective of this study was to evaluate the effectiveness of supplementing a group of premenopausal women who were free of breast carcinoma with a dietary supplement of isoflavones (40 mg per day) in producing a change in steroid hormones and menstrual cycle length.

Methods: Sixty-eight consecutively recruited, premenopausal, omnivorous women of all races and ethnicities between the ages of 25 years and 55 years were admitted to the study and randomized to an experimental group supplemented with soy (40 mg genistein per day) or to a control group that consumed a placebo for a 12-week period. Changes in their anthropometric, nutritional, and hormonal biomarkers from early follicular phase were analyzed at baseline and post-intervention.

Results: Serum-free estradiol and estrone levels decreased moderately in the experimental group. Serum hormone-binding globulin levels increased in 41.4% of women in the experimental group compared with 37.5% of women in the placebo group. Free estradiol decreased in 53.85% of women in the experimental group compared with 37.5% of women in the placebo group. Estrone decreased in 55.56% of women in the experimental group compared with 42.86% in the placebo group. Those women in the experimental group who were consuming soy had their mean menstrual cycle…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 14 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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