From S. BINGHAM, K SETCHELL, AEDIN CASSIDY
The information on pancreatic cancer and raw soya flour in rodents
cited by K. G. Wormsley (Letters, 6 August) was published 10 years ago,
and further data since then has been obtained and extensively reviewed.
There is little epidemiological evidence to support a relationship between
soya consumption and incidence of pancreatic cancer in humans. For example,
age standardised truncated rates for Japanese populations are between 9.1
and 12.6 per 100 000 per year in males and 5.3 to 7.0 in females. This
compares with British rates of 7.3 to 12.2 in males and 5.2 to 8.8 in
females.
Protease inhibitors are under active research. Currently a soya bean
extract, called the Bowman-Birk trypsin inhibitor concentrate, has proved
to have anti-cancer activity in animal models and in in vitro systems. In
consideration of the possible effects of protease inhibitors, we have observed
no biological effects of preparations of soya protein that contained these
inhibitors, but not isoflavones, in our recent animal and human studies.
This included anti-cancer effects, and hormonal effects on the menstrual
cycle.
S. Bingham, K. Setchell, Aedin Cassidy Dunn Nutrition Centre Cambridge
