A red clover isoflavone dietary supplement can lessen breast pain experienced by women during their menstrual cycles, researchers from Australia report this week.
The findings of Dr. David Ingram, director of the Breast Centre at Sir Charles Gairdner Hospital in Perth, Australia, and associates are the result of a 5-month study conducted with 18 women.
"We suspected that the phytoestrogens in red clover would offset the breast pain observed during menstrual cycle hormone fluctuations," said Ingram.
"We found women who received the red clover extract to report a significant reduction in their pain."
Phytoestrogens, which include isoflavones, are compounds found in plants that exhibit both mild estrogen-like and estrogen opposing effects, depending on whether the current hormone status is low or high, respectively.
They are abundant in soy and other legumes.
Some of the isoflavones found in red clover are not present in soy.
Numerous studies have indicated that isoflavones can influence the metabolism and activity of estrogens in women, suggesting they could alter their effects upon breast tissue.
In the study, women with recurrent breast pain first entered a 2-month placebo "lead-in" phase.
This was intended to screen out women who experienced a significant relief from a placebo, as breast pain is highly variable between women.
Those women who did not show a greater than 30% reduction in breast pain on placebo were then assigned to a double blind phase, receiving either a 40 or 80 mg red clover isoflavone supplement, or placebo daily.
The red clover supplement used in the study is sold in the U.S. under the brand name Promensil.
"The lead-in phase made our study quite stringent, with 65 of 83 women being 'weeded out', so our data need to be viewed as preliminary," added Ingram.
"However, nine of the 12 women who took the isoflavone supplement showed a greater than 25 per cent decline in their self-reported breast pain score, while only two of the six in the placebo group experienced such relief.
The greatest response was in the 40-mg/day group.
The women taking 80 mg/day also had a lengthening of their cycle by three days after three months of supplementation, " he concluded.
Dr. Jerry Cott, of PsychoFarmacology Consulting Services and Scientific Advisory Board member of the Dietary Supplement Education AllianceTM commented, "Future studies on isoflavones found in soy and other legumes are needed to explore the many possibilities of how these compounds can play a role in improving women's health."
Full findings are reported in the online journal Breast.