Two new studies carried out on the red clover dietary supplement Promensil show that it is effective at reducing the frequency and severity of hot flushes in menopause patients.The studies, published in the current issues of The Female Patient and Maturitas/The European Menopause Journal, add to increasing evidence that there may be alternative options to HRT treatment for combating menopause symptoms.
The first study showed that the commercially available dose (40 mg per day) of Promensil reduced hot flushes by nearly 50 per cent, while a placebo (dummy pill) used in a control group of patients reduced hot flushes by only about 10 per cent.
"This study demonstrates that dietary supplementation with red-clover derived isoflavones (Promensil) is an effective alternative for symptomatic relief of vasomotor symptoms in postmenopausal women, reducing both the average daily frequency and severity of hot flushes," said Dr Arturo Jeri director of the climacteric unit at the Institute of Gynaecology and Reproduction, Lima, Peru, and author of the study.
"Many botanical and nutritional therapies are offered for use during menopause, however Promensil has the clinical evidence supporting a favourable risk-benefit profile."
The double-blinded study reviewed data on 30 healthy, non-vegetarian women who had been postmenopausal for more than one year. The patients had not used Hormone Replacement Therapy (HRT), soy, or other oestrogen-active plant products for at least 16 weeks prior to the study. The group was divided into two equal groups of 15 patients.
The study used non-vegetarian women to avoid potential biasing from higher than usual consumption of soy and other legumes, often seen in vegetarian women. Severity of symptoms was self-measured by patients on a scale of zero (no symptoms) to three (severe, interferes with normal activities.)
Thirty women were involved in the double blind, randomized placebo-controlled Maturitas Study. All had more than five incidents of hot flushes per day. They were given a list of isoflavone-rich foods and supplements to avoid.
All the women received placebo tablets for four weeks and were subsequently randomised to either placebo or 80 mg isoflavones for a further 12 weeks. During the first four weeks of placebo the frequency of hot flushes for all the women decreased by an average of 16 per cent.
During the subsequent double-blind phase, a further, statistically significant decrease of 44 per cent was seen in isoflavones group, whereas no further reduction occurred within the placebo group. A quality of life score improved in the active group by 13 per cent and remained unchanged in the placebo group. The study authors concluded that the difference in reduction of hot flushes between the two groups "demonstrates the effectiveness of Promensil in the management of hot flashes."
"While isoflavones can be consumed in the diet, it would be extremely difficult for Western women to consume the variety of legume food plants necessary to match this supplement," said Dr Ronald Barentsen at the Department of Obstetrics and Gynecology, Vrije Universiteit Medical Centre, Amsterdam, The Netherlands, co-author of the study.
In addition to containing the two isoflavones found in soy known to have significant oestrogenic properties, genistein and daidzein, Promensil contains two additional isoflavones, formononetin and biochanin, which have been shown to bind to oestrogen receptors to produce oestrogen-like effects.
"Although a range of isoflavone dietary supplements are now available, those produced from red clover offer the benefit of containing all four important isoflavones and Promensil provides these in a form standardised with respect to concentration and ratio," said Dr. Barentsen.
Authors of the study published in Maturitas add that there has been no evidence of adverse oestrogenic effects on the endometrium with red clover isoflavones, "alleviating concerns of undesirable side effects associated with (Hormone Replacement Therapy)."
"Published studies indicate that phytoestrogens work similarly to the class of medications known as selective oestrogen receptor modulators, that is, they stimulate some cells but not others, and they don't stimulate cells that contribute to hormone-dependent cancers," said Mark Blumenthal, founder and executive director of the nonprofit American Botanical Council in Austin, Texas.
"The Asian populations that consume a high volume of the same isoflavones found in red clover and soy have lower rates of hormone-dependent cancer," said Blumenthal.
Promensil is made by Novogen, a pharmaceutical company based in Sydney, Australia. The company focuses on isoflavone supplements and drug discovery for disorders that are commonly associated with ageing.