New evidence suggests that eating lots of soya products while pregnant may increase the risk of breast cancer in female offspring.
The study by Dr Mary Enig suggests that the risk is dose dependent and that maternal exposure to genistein a phytoestrogen present in soya is responsible (Oncol Rep, 1999; 6: 1089-95).
More and more research is suggesting that phytoestrogens are not the weak oestrogens they have been promoted to be (see cover story, page 1). The findings of this study confirm studies in vitro and in vivo showing that genistein acts in a similar way to natural oestrogens.
Another study has shown that soya may not be much of a bone healing miracle either at least in animals.
Rats that ate common herbs and vegetables, such as a mixture of garlic, lettuce, tomato, cucumber, arugula, onion and parsley, had significantly less bone loss than those that did not have such a diet. Interestingly, soya beans and soya milk products had no effect on the animals' bones. Future studies need to be done to determine if soya has the same effect on humans (Nature, 1999; 401: 343-4).