Phytoestrogens for menopausal vasomotor symptoms

Area of Science:

• Menopause Research
• Phytochemistry
• Women's Health

Background:

• Vasomotor symptoms (hot flushes, night sweats) are common during menopause.
• Hormone therapy is effective but carries risks, increasing interest in alternatives.
• Phytoestrogens, plant compounds with estrogenic action, are popular alternatives.

Purpose of the Study:

• To evaluate the efficacy, safety, and acceptability of phytoestrogen-rich foods, extracts, and supplements.
• To compare these interventions against no treatment, placebo, or hormone therapy.
• To assess their impact on vasomotor symptoms in perimenopausal and postmenopausal women.

Main Methods:

• Systematic review of 43 randomized controlled trials (4,364 participants).
• Searches included multiple databases up to July 2013; grey literature and reference lists were also checked.
• Studies were grouped by phytoestrogen type (soy, red clover, genistein); meta-analysis was performed where possible.

Main Results:

• No significant difference in hot flush frequency between red clover extract (Promensil) and placebo.
• Four trials suggested genistein extracts (>30 mg/d) consistently reduced hot flush frequency.
• Many trials were small, at high risk of bias, and showed a strong placebo effect; no adverse effects were noted.

Conclusions:

• No conclusive evidence supports phytoestrogen supplements for reducing menopausal vasomotor symptoms.
• Further investigation into genistein concentrates is warranted for potential therapeutic benefits.
• Phytoestrogens were not associated with adverse endometrial or vaginal effects up to two years.