Small servings of vegetables or a cruciferous supplement do not affect urinary estrogen metabolites in premenopausal women

Abstract

BackgroundThe ratio of urinary 2‐hydroxyestrone to 16‐α‐hydroxyestrone (2:16) is hypothesized as a potential biomarker of breast cancer risk in premenopausal women, with higher ratios theoretically protective. Cruciferous vegetable intake has been inconsistently associated with higher urinary 2:16.ObjectiveWe investigated whether or not a cruciferous vegetable supplement made from dried Brussels sprouts and kale, would increase the urinary 2:16 estrogen metabolite ratio in comparison to placebo or cruciferous vegetables in healthy premenopausal women.DesignThis registered (NCT01726127) parallel arm, placebo‐controlled, partly blinded study included 78 healthy premenopausal women (38–50 years) with screening urinary 2:16 ≤ 3.0 who were not using exogenous hormone treatment. Subjects were randomly assigned to receive 1) Crucifer supplement 2) 40 g daily alternating broccoli or Brussels sprouts or 3) placebo daily for eight weeks. Urinary 2:16 was measured at baseline, four, and 8 weeks. Serum chemistries of progesterone, estradiol, estrone, luteinizing hormone, and follicle‐stimulating hormone were analyzed.ResultsIntent‐to‐treat repeated measures‐ANOVA identified no treatment effect on urinary 2:16 (P = 0.83) or treatment by time interaction (P = 0.79). Per‐protocol analyses including only complete cases found no significant treatment by time interaction (P = 0.63) and restricting the analysis to subjects with minimum 80% verifiable compliance to treatment found similar results (Ptreatment = 0.90 Pinteraction = 0.86).ConclusionsNeither the crucifer supplement nor a small serving of cruciferous vegetables significantly altered the urinary 2:16 estrogen metabolite ratio in healthy premenopausal women.Support or Funding InformationThis project was funded by Standard Process, Inc. (Palmyra, WI).