Isoflavones found in soya beans, among others, have the ability to regulate many phenomena associated with uncontrolled growth of cancer cells: they block the activity of many enzymes involved in uncontrolled growth of cancer cells, and can therefore reduce the risk of prostate and breast cancer. A multi-year study of nearly 12,395 men in California showed that daily consumption of at least one glass of soya milk leads to an approximately 70 per cent reduction in the risk of prostate cancer.

At present, soy-based products such as miso, soy sauce, tofu, soy milk and raw and roasted beans are generally available in Poland. Research is still ongoing to definitively confirm whether there is a link between women's soya consumption and breast cancer risk. However, at this stage, it is already known that a moderate soy consumption of approximately 50-100g/day has a positive effect on health, reducing the risk of breast cancer and prostate cancer, among others. Recent studies also indicate a possible preventive effect of isoflavones for thyroid, head and neck cancers.

Soy preparations are widely available in pharmacies and are very often taken by menopausal women. However, there is not really a need for such preparations, as scientific reports show that such supplements can accelerate the development of breast cancer in laboratory mice with low oestrogen levels.