Thomas J.A. set out to observe the effects that intermittent fasting had on a mouse that had prostate cancer in his experiment. Thomas began his abstract presentation by acknowledging that caloric restriction (CR) has been shown to have anti-cancer properties. “However, CR may be difficult to apply in humans secondary to compliance and potentially deleterious effects.”
Thomas presents an alternative to CR; intermittent caloric restriction. However, in “extreme cases” intermittent fasting is a better alternative. 100 male mice, impaired with severe combined immunodeficiency (all of these mice were 7-8-week-old), were injected with approximately 1 x 105 LAPC-4 prostate cancer cells.
Mice were randomly assigned to either an ad libitum Western Diet (44% carbohydrates, 40% fat and 16% protein) or an ad libitum Western Diet consisting of twice-weekly 24-hour fasts (IF). The measurements of tumor volume and mouse bodyweight were conducted twice weekly. “Mice were killed when tumor volumes reached 1000 mm3.”
The collection of both serums and tumors were done for an analysis of the insulin/insulin-like growth factor 1 (IGF-1) hormonal axis. There was no difference in the survival of the mice or the tumor volumes between groups. The mice that intermittent fasted experienced “significantly higher serum IGF-1 levels and IGF-1/IGFBP-3 ratios at killing (P<0.001).” However, a difference in the serum insulin, IGFMP-3, and tumor phospho-Akt levels were not detected.
In this study, intermittent fasting did not improve the survival rates of the mice, nor did it delay prostate growth. “This may be secondary to metabolic adaptations to the 24h fasting periods. Future studies are required to optimize CR for application in humans,” remarked Thomas J.A.
- Thomas, J.A., 11, et al. “Effect of intermittent fasting on prostate cancer tumor growth in a mouse model.” Prostate Cancer and Prostate Diseases, vol. 13, no. 4, 2010, p. 350+.Academic OneFile, Accessed February 2018.