ORLANDO – Lignan-type phytoestrogens, but not isoflavone-type phytoestrogens, were associated with a decreased risk for incontinence symptoms in women, based on findings from a large prospective population-based cohort study.
Lignan-type phytoestrogens are found in a wide variety of plant-based foods including flaxseeds, sesame seeds, legumes, whole grains, fruits, and vegetables. Isoflavone-type phytoestrogens are found primarily in soybeans and soy-based products.
The study is the first to demonstrate an association between urinary phytoestrogen levels and urinary symptoms, according to the study’s author, Dr. Evgeniy I. Kreydin of Massachusetts General Hospital, Boston. Prospective studies are warranted to investigate the mechanism for this relationship, he added.
Increasing concentrations of the lignan phytoestrogens enterolactone and enterodiol were associated with significantly decreased likelihood of urge incontinence, bother from incontinence, and effect of urinary incontinence on daily living in 4,104 women who participated in the NHANES (National Health and Nutrition Examination Survey) between 2000 and 2010. Increasing concentrations of enterolactone were also associated with significantly decreased likelihood of "other incontinence," Dr. Kreydin reported during an "outstanding posters" session at the annual meeting of the American Urological Association.
Odds ratios for urinary symptoms per unit change in urinary enterodiol and enterolactone concentrations, respectively, were 0.43, 0.49, 0.32, and 0.14, and 0.47, 0.32, 0.30. The odds ratio per unit change was 0.24 for urge incontinence, other incontinence, incontinence bother, and incontinence effect on daily activities, Dr. Kreydin said.
Alternatively, none of the isoflavone-type phytoestrogens was associated with decreased urinary symptoms in this study. In fact, one isoflavone-type phytoestrogen – genistein – was associated with an increased likelihood of incontinence bother (odds ratio, 2.45).
Study subjects completed a urinary function and quality of life questionnaire and underwent measurement of urinary phytoestrogen levels. Urinary symptoms were assessed after adjusting for age, race, smoking status, body mass index, diabetes, parity, and menopausal status – factors known to affect lower urinary tract symptoms in women.
Dr. Kreydin reported having no relevant financial disclosures.