Soya foods are a rich source of isoflavones, a major group of phytoestrogens, which act like oestrogen in the body. They also contain high amounts of dietary fibre.
Researchers interviewed 832 women who were diagnosed with endometrial cancer between 1997 and 2001 and were between the ages of 30 and 69 years in Shanghai, China. A further 846 healthy women of the same age were randomly selected as a control group. Soya food intake over five years was measured and current body measurements were taken.
Regular consumption of soya foods was associated with a reduced risk of endometrial cancer, particularly among overweight women.
Rates of endometrial cancer vary more than 10-fold worldwide. Asian women have a lower incidence of endometrial cancer and eat more soya food than their Western counterparts. These findings suggest that dietary factors may play an important role in this international variation, say the authors.
The indication that overweight women may benefit more from increased soya food intake needs to be verified in future studies, they conclude.