Menopause is not a disease or a state of oestrogen deficiency. It is an age-appropriate, natural decline in oestrogen levels. Even though alternative therapists accept this, they are still passing out 'prescriptions' for natural oestrogen and progesterone with impunity.
But research into 'natural' hormones has been as sloppy as that into the synthetic ones - observational, short-term, and lacking in placebo controls and recording of adverse side-effects.
The emerging view is that phytoestrogens - plant-derived oestrogens - are not exactly the 'weak' oestrogens we have assumed that they are. It seems they can, in sufficient quantities, evoke all the same responses as other oestrogens (Endocrinology, 1998; 139: 4252-63). For instance, coumoestrol, found in high doses in red clover, has been shown to have powerful oestrogenic effect - six times that of other isoflavones (Proc Soc Exp Biol Med, 1995; 208: 44-50).
High intake of dietary soya, even over the short-term, can significantly stimulate the proliferation rate of breast lobular epithelium (Am J Clin Nutr, 1998; 68 [6 Suppl]: 1431S-5S).
What's more, in a recent laboratory study of the effects of different phytoestrogens on oestrogen-receptor-positive breast cancer cells, red clover proved to have the same effect on cell growth as oestradiol (Proc Soc Exper Biol Med, 1998; 217: 369-78).