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


OBJECTIVE
To evaluate the effect of high-dose isoflavones on self-reported quality of life (QOL), cognition, lipoproteins and androgen status in post-menopausal women.


METHODS
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.


METHODS
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Internal Medicine, Division of Endocrinology and Metabolism, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. shehzad.basaria@bmc.org
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Basaria
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Wisniewski
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Dupree
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Bruno
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Song
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Yao
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Ojumu
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John
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Dobs
D000368:Aged; D000728:Androgens / Q000097:blood*; D003071:Cognition / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D008074:Lipoproteins / Q000097:blood*; D008875:Middle Aged; D017698:Postmenopause / Q000187:drug effects; D011788:Quality of Life; D030262:Soybean Proteins / Q000008:administration & dosage
D000728:Androgens; D007529:Isoflavones; D008074:Lipoproteins; D030262:Soybean Proteins