Tice JA, Ettinger B, Ensrud K, Wallace R, Blackwell T, Cummings SR.
Phytoestrogen supplements for the treatment of hot flashes: the Isoflavone Clover Extract (ICE) Study: a randomized controlled trial.
JAMA. 2003 Jul 9;290(2):207-14.

Review

Hot flushes are the most common symptom that causes women to seek medical treatment for menopause. With recent concerns being raised about long-term hormone replacement therapy, women seek to use different alternative therapies for menopausal symptoms. It is known that only 10 – 20% of Asian women report suffering from hot flushes as compared to 70 – 80% of women in Western countries. It has been proposed that this difference is due to differences between the Asian and western diets. Asian diets typically are high in compounds called isoflavones, which are mostly found in soy products. Isoflavones are structurally related to estrogens and are known to bind to the estrogen receptor in the body. It has been suggested that a high intake of soy products (isoflavones) offers Asian women some protection against the estrogen deficiency symptoms of menopause such as hot flushes and night sweats.

This particular study evaluated the use of 2 different) supplements, Promensil and Rimostil, containing isoflavones derived from red clover. Their effectiveness in treating menopausal hot flushes was compared to placebo (dummy pill). The study was conducted over a 12 week period and involved 252 women. The women were recently postmenopausal and were experiencing on average 8 hot flushes per day. The group receiving Promensil received 82 mg of isoflavones per day while the group receiving Rimostil received 57 mg of isoflavones per day. These doses generally represent high dose isoflavone therapy.

In each of the three treatment groups (Promensil, Rimostil and Placebo) there was a reduction in the average number of hot flushes from 8 to 5 hot flushes per day. It was noted that the reduction in hot flushes in the group of women taking Promensil occuried earlier than for the other two groups. However the reduction in hot flushes in the women taking supplements was no different to that for women taking placebo treatment. The observed fall in the number of hot flushes in the treatment group is due to placebo affects of being on a trial.

(The placebo affect refers to a known phenomena, where by study subjects receiving placebo treatments still manifest a clinical improvement, because of a belief that they are being given a drug treatment. When this manifests in the group taking study medication, it means that the study medication is no more affective than the placebo treatment).

The outcome of this large well conducted study is that the supplements, Promensil and Rimostil, are no more effective in the treatment of menopausal hot flushes than placebo therapy.

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Content updated November 12, 2003