The report though is quite clear: "traditional Japanese soy-based foods on a regular basis".

Traditional soy foods are fermented for up to 18 months. According to tradition non-fermented soy is not easily digestible. The prized soy foods are those that have gone through two seasons of fermentation.

Western soy products by and large do not go through that fermentation process. They are chemically treated to make them digestible.

What's wrong with that? We're beginning to learn a lot about fermentation. The east Europeans under communism had a poor diet other than the fact that they ate plenty of naturally preserved (fermetned) foods. And now ferments are being touted as an avian flu preventive.

So by all means eat western soy products but don't expect eastern soy benefits.

The study followed approximately 25,000 women aged between 40 and 69 throughout Japan for an average of 10 and a half years. They found the fermented soy products reduced breast cancer risk by a third.

They warned however that taking supplements could lead to excess levels of the compounds that prevent cancer.