Title: Null effect of dietary restriction on prostate carcinogenesis in the Wistar-Unilever rat.
Authors: McCormick, David L; Johnson, William D; Haryu, Todd M; Bosland, Maarten C; Lubet, Ronald A; Steele, Vernon E
Published In Nutr Cancer, (2007)
Abstract: Chronic dietary restriction inhibits carcinogenesis in several sites in laboratory animals. To determine the effects of dietary restriction on prostate carcinogenesis, prostate cancers were induced in male Wistar-Unilever rats by a sequential regimen of cyproterone acetate (50 mg/day; 21 days); testosterone propionate (100 mg/kg/day; 3 days); N-methyl-N-nitrosourea [MNU; 30 mg/kg; single dose]; and testosterone (subcutaneous implants of 2 pellets containing 40 mg each). Dietary restriction (0% [ad libitum control], 15%, or 30%) was initiated 2 wk post-MNU, and continued until study termination at 12 mo. Dietary restriction induced a rapid suppression of body weight gain but conferred no protection against prostate carcinogenesis. 74% of carcinogen-treated ad libitum controls developed accessory sex gland cancers, versus cancer incidences of 64% and 72% in groups restricted by 15% and 30%, respectively. Similarly, 44% of dietary controls developed cancers limited to the dorsolateral/prostate, versus incidences of 45% and 53% in groups restricted by 15% and 30%. The results of the present study do not support the hypothesis that prostate carcinogenesis can be prevented by reducing caloric intake. Reducing mean body weight by up to 25% through chronic dietary restriction has no effect on the induction of prostate cancers in the Wistar-Unilever rat model.
PubMed ID: 17571953
MeSH Terms: Animals; Carcinogens/toxicity*; Cyproterone Acetate/toxicity; Diet, Reducing*; Dose-Response Relationship, Drug; Humans; Male; Methylnitrosourea/toxicity; Prevalence; Prostatic Neoplasms/chemically induced; Prostatic Neoplasms/epidemiology; Prostatic Neoplasms/prevention & control*; Rats; Rats, Wistar; Testosterone Propionate/toxicity; Testosterone/blood; Testosterone/toxicity; Treatment Outcome; Weight Gain/drug effects*