Soya and Cancer

Soy products have received a lot of interest in the past few years.  Food products made from Soybean have long been touted as healthy additions to the western diet. Tofu, Soy Milk and other soy products work to promote healthy cholesterol levels and have been said to help protect from certain types of cancer, including breast, colon and prostrate cancer.

Claims have been made that eating foods made from Soya beans can help prevent breast cancer or help treat it once it has been diagnosed.  There are also claims that it can replace hormone replacement therapy in menopausal women.

However, Soy (Soya) has its dark side: it has a weak estrogen effect, and its long-term effects on breast cancer are not known. Soy may also decrease the absorption of thyroid medication, so the combination of the two should be avoided.

In a nutshell, at least at this time there is no clear answer to the question of soy's potential contribution to, or protection from, breast cancer.  The experts are split on this question. What research does exist on this topic is conflicting and confusing. Hundreds of small studies on isoflavones and breast cancer have found dramatically different results.

Soybeans are a melange of complex chemical components. Their main components are protein, essential fatty acids, and to a lesser degree what are known as isoflavones. While isoflavones are found in other legumes, the versions in soybeans are also phytoestrogens: plant-derived weak estrogens, chemically similar to the female hormone estrogen. Because isoflavones behave like estrogen, in certain situations, they could stimulate the growth of estrogen-dependent.

Research data, however, is far from conclusive, and some studies show just the opposite: that under some conditions, soy may help prevent breast cancer.

Some physicians caution breast cancer patients against eating too much soy for fear it could promote tumour growth in women whose disease is sensitive to estrogen. In addition, health agencies of New Zealand, Australia, and Great Britain have voiced concern about the safety of soy-based infant formula for fear that it might spark reproductive or thyroid problems in babies in later life. 

In 1999 the Food and Drug Administration allowed food manufacturers to claim that soy-based foods help lower the risk of heart disease.

Here is a couple of links I found on the net on Soya. The links explain both sides of the story:

Soy cancer warning

Soya breast cancer link dismissed

Conclusion : I am not a Doctor to give sound medical advice. My knowledge is based on reading. It will take many years before enough research is completed and we know whether soy products have any effect on cancer.  In the meantime, it probably isn’t a good idea to eat large amounts of them if you have been diagnosed with cancer.