Positive Health Online

Abstract

POLLARD and LUCKERT, Lobund Laboratory, University of Notre Dame, IN 46556 USA studied the influence of soy protein isoflavones upon development of prostate-related cancers in rats.

Background

Methodology

Lobund-Wistar rats were fed soy protein isolates with high isoflavones (genistein and daidzein ) or low isoflavones to determine their effects upon development of induced PSV tumours in two stages of the tumour process.

Results

Compared with rats fed the same diet but low in isoflavones, in rats fed the high-isoflavone-supplemented soy diet prior to tumour initiation, incidence of induced prostate-related cancer was reduced and the disease-free period was 27% longer . In rats fed the same diets started after initiation, results were suggestive but less consistent than the above. Incidence rates were of marginal significance, suggesting that the high intensity of the active induced disease may not represent the character of the slower-growing spontaneous (natural) disease. The delay of disease onset is clinically significant.

Conclusion

: The isoflavones genistein and daidzein appear to reduce prostate tumour incidence and prolong disease-free period.

References

Pollard M and Luckert PH. Influence of isoflavones in soy protein isolates on development of induced prostate-related cancers in L-W rats. Nutr Cancer. 28(1): 41-5. 1997.