Caloric Restriction Inhibits While Obesity Fuels Cancer Growth
Findings by Diovanni, et al indicate that a caloric restrictive diet inhibits the growth of
cancer in mice. Mice studies further indicated that obesity in mice enhanced the signaling through pathways that stimulated the growth of papilloma formation. Papillomas are known precursors to cancer.
The study used four diets, two representing calorie reductions of 30 percent and 15 percent, a control diet containing ten percent of calories from fat and an obesity inducing diet containing 60 percent calories from fat. Agents were then given to the mice to induce papilloma formation. Those mice on the calorie restricted diet had statistically significant inhibition of papilloma formation compared with the other two diets.
In a separate experiment, it was demonstrated that the development of carcinomas and the effect of dietary energy balance on conversion of the papilloma lesion to cancer was evaluated. It was found that energy balance determines the number of carcinomas found through its effects on the number of premalignant lesions but does not affect the rate of malignant conversion.
Calorie restriction and obesity both affect the activation of epidermal growth factor and insulin-like growth factor receptors. These receptors are involved in such molecular pathways as Akt and mTOR.
It is not a new finding that obesity increases the incidence of some cancers and this study, recently reported to American Association for Cancer Research, backs up other epidemiological findings between energy balance and the development of cancer.
The conclusion of this study is that the Akt and mTOR pathways are known to be important for skin tumor development in this model system. In addition, increased Akt and mTOR signaling are linked to the growth, proliferation and survival of many human cancers. “These findings provide the basis for future translational studies targeting Akt/mTOR pathways through a combination of lifestyle and pharmacological approaches to prevent and control obesity- related epithelial cancers in humans.”
Source: University of Texas M.D. Anderson Cancer Center
About the Author
Kathy Shattler received her Master of Science degree from Michigan State University in E. Lansing Michigan in Human Nutrition. Her twenty-two years of practice includes holding positions as a Lecturer, Chief Clinical Dietitian and Program Manager. Kathy is the Founder of Nutri-Care Consulting and is currently the Nutrition Director of www.CEU4U.COM, an online continuing education management company for Registered Dietitians and Dietetic Technicians.
