HAILED as the "natural" and healthy alternative to hormone replacement therapy, plant oestrogens are also said to help prevent cancer, strokes and bone loss following the menopause. But they could also pose a health risk, as evidence emerges that they act like "gender-bending" pollutants that may increase the risk of cancer.
Many foods, including soya, olives and onions, are rich in plant oestrogens, and extracts rich in these substances are marketed as a tonic for menopause symptoms. Some studies in rats have hinted that they protect women against breast cancer, an idea bolstered by the fact that Japanese women, who eat a lot of soya, have one-sixth the Western incidence of breast cancer.
But some experts remain unconvinced of these benefits. "The evidence that plant oestrogens protect against cancer is very circumstantial," says Chris Kirk at the University of Birmingham. Genetic differences make populations difficult to compare, he points out. ...
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