Urinary isoflavone and lignan phytoestrogen levels and risk of uterine fibroid in Jamaican women.

BACKGROUND: Isoflavones and lignans are phytoestrogens, and therefore, are able to bind to and activate estrogen receptors. The resultant estrogenic or antiestrogenic effect is dependent on the concentration of these phytoestrogens relative to endogenous estrogens and the site of their action, among others. Thus, isoflavones and lignans act as selective estrogen receptor modulators; having a beneficial effect in some tissues while simultaneously causing deleterious changes in others. OBJECTIVE: This case-control study investigates the relationship between urinary concentrations of genistein, daidzein, equol, and enterolactone, and the presence of uterine leiomyomas (fibroids) in Jamaican women. DESIGN: Phytoestrogen concentration in spot urine samples from 157 uterine fibroid cases and 171 fibroid-free controls diagnosed by ultrasonography, were assessed by Time-resolved Fluoroimmnoassay. Statistical evaluations were performed using SPSS 12.0. RESULTS: The median concentration of urinary enterolactone was significantly different between uterine fibroid cases and controls (p=0.029). However, this was not observed to affect risk of uterine fibroid, as trends across quartiles of urine enterolactone did not differ significantly between cases and controls. Median urinary genistein (p=0.510), daidzein (p=0.838), equol (p=0.621), total isoflavones (0.510) and total phytoestrogens (p=0.084) were similar for both groups. Binary logistic regression analysis of quartiles of urine genistein, daidzein, equol, enterolactone, total isoflavones, and total phytoestrogens showed no association with uterine fibroid. CONCLUSIONS: Uterine fibroid cases had a higher median urine concentration of enterolactone compared with controls. However, this was not observed to affect ones risk of fibroid. Neither was urine genistein, daidzein, equol total isoflavones, and total phytoestrogens observed to be associated with risk of uterine fibroid.

Urinary phytoestrogens and risk of prostate cancer in Jamaican men.

We evaluated the relationship of spot urinary concentrations of phytoestrogens with total prostate cancer and tumor grade in a hospital-based case-control study in Jamaica. Urine samples were analyzed for genistein, daidzein, equol (isoflavones), and enterolactone (lignan) among newly diagnosed cases (n = 175) and controls (n = 194). Urinary concentrations of enterolactone (lignan) were higher among cases. There were no significant differences in median concentrations of isoflavone excretion. Compared with non-producers of equol (reference tertile), men who produced equol were at decreased risk of total prostate cancer (tertile 2: OR, 0.42; CI, 0.23-0.75) (tertile 3: OR, 0.48; CI, 0.26-0.87) (p (trend), 0.020) and high-grade disease (tertile 2: OR, 0.31; CI, 0.15-0.61) (tertile 3: OR, 0.29; CI, 0.13-0.60) (p (trend), 0.001). Higher concentrations of enterolactone were positively related to total prostate cancer (OR, 1.85; CI, 1.01-3.44; p (trend), 0.027) as well as high-grade disease (OR, 2.46; CI, 1.11-5.46; p (trend), 0.023). There were no associations between urinary excretion of genistein and daidzein with risk of prostate cancer. Producers of equol (isoflavone) may be at reduced risk of total- and high-grade prostate cancer whereas enterolactone may increase the likelihood of disease.