Researchers with the UNC Lineberger Comprehensive Cancer Center examined whether weight loss for four different diets was linked to reduced tumor growth in laboratory models of breast cancer. While tumor size did not differ between obese mice and obese mice that returned to a normal weight on a low-fat diet, they did find that obese mice lost significant amounts of weight on three calorie-restricted diets had smaller tumors.
“Based on our results, it appears that the degree of calorie restriction, and hence the amount of weight lost, matters more than the specific dietary changes used to generate the weight loss,” said Laura Bowers, PhD, a postdoctoral fellow in the UNC Lineberger Cancer Control Education Program. “Our findings are too preliminary to make any kind of recommendation for people. The overall message is that the breast cancer-promoting effects of chronic obesity may not be easily reversible with moderate weight loss, but more severe weight loss diets may be effective regardless of whether carbohydrate or fat is restricted.” This is an issue of increasing importance as the obesity epidemic in the United States and throughout the world is increasing the prevalence of obesity-related cancers, and obesity also makes cancers more deadly,” Hursting said. “We are working to identify mechanism-based interventions in our experimental models that can reverse the adverse effects of chronic obesity on cancer burden.”
Bowers works in the lab of Stephen Hursting, PhD, MPH, a UNC Lineberger member and professor in the UNC Gillings School of Global Public Health and the UNC Nutrition Research Institute. The study is part of the research effort by Hursting’s laboratory to understand, and potentially reverse, the cancer-promoting effects of obesity.
“This is an issue of increasing importance as the obesity epidemic in the United States and throughout the world is increasing the prevalence of obesity-related cancers, and obesity also makes cancers more deadly,” Hursting said. “We are working to identify mechanism-based interventions in our experimental models that can reverse the adverse effects of chronic obesity on cancer burden.”