Effect of high-dose isoflavones on cognition, quality of life, androgens, and lipoprotein in post-menopausal women

Department of Internal Medicine, Division of Endocrinology and Metabolism, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Journal of endocrinological investigation (Impact Factor: 1.45). 03/2009; 32(2):150-5. DOI: 10.1007/BF03345705
Source: PubMed


Recent interventional studies indicate that post-menopausal hormone replacement therapy is associated with an increased risk of cardiovascular mortality and breast cancer. Isoflavones, a class of plant estrogens, have structural similarities to estradiol. Hence, isoflavones may exert beneficial estrogenic health effects in postmenopausal women with fewer adverse effects.
To evaluate the effect of high-dose isoflavones on self-reported quality of life (QOL), cognition, lipoproteins and androgen status in post-menopausal women.
Double-blind, randomized, placebo-controlled, 12-week trial of 93 healthy, ambulatory, post-menopausal women (mean age 56 yr). The study was conducted at a tertiary care center in the United States.
Participants were randomly assigned to receive 20 g of soy protein containing 160 mg of total isoflavones vs taste-matched placebo (20 g whole milk protein). Both soy and the placebo were provided in the form of a powder to be mixed with beverages.
QOL was judged by the Menopause-specific Quality of Life (MENQOL) questionnaire while cognitive function was assessed with standard instruments. Total, free, and bioavailable testosterone, gonadotropins, SHBG, and fasting lipids were measured.
Eighty-four women (90%) completed the study (active=38, placebo=46). There was a significant improvement in all 4 QOL subscales (vasomotor, psychosexual, physical, and sexual) among the women taking isoflavones, while no changes were seen in the placebo group. No significant changes in cognition, serum androgens or plasma lipids were seen within any of the groups. However, at the end of the study, a group-by-time interaction was observed such that total testosterone and HDL levels were significantly lower in the isoflavones compared to placebo groups.
High-dose isoflavones is associated with improved QOL among women who have become menopausal recently. Hence, the timing of isoflavone supplementation with regards to the onset of menopause appears to be important. The use of isoflavones, as an alternative to estrogen therapy, may be potentially useful and seemingly safe in this group of women who are looking for relief from menopausal symptoms.

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    • "c o m / l o c a t e / n e u t e r a ingredients may aide in healthy cognitive aging. For instance, reports of the effects of several commercially available dietary soy-based supplements (with mixed isoflavone contents/concentrations) on learning and memory processes from randomized controlled studies in aging women vary, reporting no effect (Basaria et al., 2009; Fournier et al., 2007; Henderson et al., 2012; Ho et al., 2007; Kreijkamp-Kaspers et al., 2004), some improvement (Casini et al., 2006; Duffy et al., 2003; File et al., 2005; Gleason et al., 2009; Kritz-Silverstein et al., 2003; Santos- Galduroz et al., 2010), or even an impairment (Kritz-Silverstein et al., 2003). In addition to isoflavone composition, methodological differences in age at the time of treatment, previous HRT use, cognitive domain tested , and length of treatment likely contribute to the conflicting findings among published reports (see also Sumien et al., 2013). "
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    ABSTRACT: The use of over-the-counter botanical estrogens containing isolated soy isoflavones, including genistein and daidzein, has become a popular alternative to traditional hormone therapies. Menopausal women use these products as an aide in healthy aging, including for the maintenance of cognitive function. The safety and efficacy of many of these commercial preparations remains unknown. Previous research in our lab found that treatment of ovariectomized (OVX) female Long-Evans rats with genistein impaired working memory in an operant delayed spatial alternation (DSA) task and response learning in a plus-maze, but enhanced place learning assessed in the plus-maze. The present study further examined the effects of isolated isoflavones on working memory and place learning by treating middle-aged (12-13month old) OVX female Long-Evans rats with S-equol, the exclusive enantiomer produced by metabolism of daidzein in the mammalian gut. S-equol binds selectively to ERβ with an affinity similar to that of genistein but has low transcriptional potency. For DSA testing, S-equol at 1.94, 0.97mg, or 0mg (sucrose control) was orally administered to animals daily, 30minutes before behavioral testing, and again both 4 and 8hours after the first treatment. Rats were tested on the DSA task following the first, morning dose. For place learning, rats received 0.97mgS-equol every 4hours during the light portion of the cycle beginning 48hours prior to behavioral testing (total exposure 8.7mgS-equol). S-equol treatment was largely without effect on the DSA and place learning tasks. This is the first study to test the behavioral effects of isolated S-equol in OVX rodents, and shows that, unlike genistein or estradiol, repeated daily treatment with this isoflavone metabolite does not alter learning and memory processes in middle-aged OVX rats.
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    • "It is a secondary metabolite that forms during the growth of soybean. With a chemical structure similar to estrogen, it is also named as a phytoestrogen[1]. Recent research showed that SIF had anti-aging properties and many other biological functions[2] . "
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    PLoS ONE 11/2013; 8(11):e79698. DOI:10.1371/journal.pone.0079698 · 3.23 Impact Factor
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