An Austrian study into natural plant foods published in the journal Scilog says that the group of natural chemicals known as isoflavones found in soy plants have a, "marked impact on the hormonal balance of women". The new research methods decipher how plants and medicinal substances affect hormone balance. The concern is that the initial findings show that in high doses some of the so-called 'natural' or 'herbal' substances actually promote the growth of breast cancer cells.
Risk of taking 'natural' food supplements
It is well documented that the growth of breast tumours can be promoted by oestrogens. As many tumours develop during menopause and postmenopause in women, the treatment of menopausal symptoms with oestrogen is known to carry risk. For this reason, women increasingly resort to natural alternatives to alleviate their complaints, and this form of 'self-medication' may often last for years. Popular substitutes include the phytoestrogens such as those found in the following plants:
- red clover or
- black cohosh (Cimicifuga racemosa),
all of which are readily available as food supplements.
Unwanted increase in oestrogen
Headed by pharmacist, Dr Walter Jäger the research team at the University of Vienna’s Division of Clinical Pharmacy and Diagnostics looked at the cancer forming cell lines in the presence and absence of these 'natural' phytoestrogens.
Soy contains some isoflavones called genistein and daidzein, the research showed an interaction between these chemicals and endogenous oestrogen. Analysis showed a marked influence on the metabolism of these oestrogens in breast cancer cells.
In the case of hormone-dependent breast cancer, Walter Jäger therefore advises against isoflavone-containing food supplements. He goes onto warn that, “It might even be that the growth of tumour cells could be stimulated in a woman who has breast cancer and eats tofu twice a day”.
What is safe and effective HRT?
When asked for his view on the so-called natural or herbal products, senior consultant gynaecological endocrinologist, Mr Mike Savvas said, "These products are not necessarily safer because they are 'herbal', and they have certainly not been tested as rigorously as licensed pharmaceutical products". He goes onto say, "we only prescribe oestradiol as part of a bespoke HRT treatment and only prescribe bio-identical estradiol, which is identical to that hormone naturally and normally produced by women. This product is now well known to be safe and effective in the long term".
"It is also worth noting", says Mr Savvas, "the benefits of appropriately prescribed HRT in terms of treating the symptoms of HRT and the protection it gives against osteoporosis and heart disease far outweigh any risk. This cannot be said of the herbal products".
Anyone concerned about the getting the treatment for the symptoms of menopause right should seek the advice of qualified consultant gynaecologists specialising in endocrinology.
The time of a woman’s life when her ovaries stop releasing an egg (ovum) on a monthly cycle, and her periods ceaseFull medical glossary