Use of phytoestrogens and effects perceived by postmenopausal women: result of a questionnaire-based survey

BACKGROUND Use of food supplements-containing phytoestrogens among postmenopausal women is rapidly increasing. Although phytoestrogens are often perceived as safe, evidence for overall positive risk-benefit profile is still inconclusive. The chance to buy them by user's initiative does not facilitate surveys on their prevalence and pattern of use. The aim of this study was to describe the pattern of use and self-reported positive and negative perceptions of phytoestrogens in post-menopausa. METHODS A questionnaire was administered to women who were buying food supplements containing phytoestrogens in 22 pharmacies located in the Bologna area (400,000 inhabitants). Questionnaire was structured into 3 sections: (a) socio-demographic information, (b) pattern of use, (c) positive and negative perceptions. RESULTS Data on 190 peri- and post-menopausal women (aged 38-77) were collected. Women stated to use phytoestrogens to reduce hot flushes (79%), insomnia (15%), mood disturbances (14%) and prevent osteoporosis (15%). The majority (59%) took phytoestrogens routinely, whereas 28% in 3-month cycles. Among positive perceptions between short- and long-term users, a not negligible difference was reported for relief of hot-flushes (68% in short-term vs. 81% in long-term users; p = 0.04). Negative perceptions were reported more frequently in the long-term group, and this difference was statistically significant for edema (6% in short-term vs. 17% in long-term users; p = 0.04), but not for other effects: e.g., swelling sensation (10% vs. 21%; p = 0.09), somnolence (7% vs. 10% p = 0.62), fatigue (4% vs.11% p = 0.15). CONCLUSIONS In the Bologna area, the pattern of use of phytoestrogens for menopausal symptoms is heterogeneous, and women overall find these substances to be beneficial, especially for relief of hot-flushes. Other positive perceptions decreased with long-term use. Negative perceptions, especially estrogen-like effects, seem to be infrequent and increase with long-term therapy. Physicians should pay attention to effects perceived by post-menopausal women and routinely monitor the use of phytoestrogens, in order to recognize possible adverse effects and actual benefits.