MMC/VICC Partnership : Research
Energy Balance Intervention for Colorectal Cancer Prevention
CO-LEADERS
- Meharry Co-Leader
Maciej S. Buchowski, Ph.D., CNS – Professor Medicine & Director, Energy Balance Laboratory
Maciej.Buchowski@Vanderbilt.edu - Vanderbilt Co-Leader
Charles E. Matthews, Ph.D., M.S. - Assistant Professor of Medicine
Charles.Matthews@Vanderbilt.edu
Lifestyle determinants of energy balance have been associated, independently and in combination, with reduced risk for both adenomatous polyps and colorectal cancer (CRC). Substantial reductions in risk have been noted among individuals reporting both a high physical activity energy expenditure and a low energy intake, suggesting that CRC risk may be reduced by the combination of increased expenditure and reduced energy intake. However, the specific molecular mechanisms underlying these associations, and the type and dose of intervention needed to obtain benefit, remain unknown. Controlled clinical trials that carefully modify and measure energy balance in humans are needed to extend our understanding of the biologic mechanisms through which energy balance influences CRC risk. Such work is critical for the translation of epidemiological and basic science findings into safe effective evidence-based preventive strategies for CRC. The long-term objective of this proposal is to systematically develop a collaborative research program that leverages the strengths of investigators within the Meharry Medical Center-Vanderbilt Ingram Cancer Center (MMC/VICC) Partnership in order to develop and test hypotheses based on energy balance interventions to reduce CRC risk in adults at risk for the disease. In the proposed pilot study, we will test the feasibility of energy balance interventions for adults at increased risk for CRC based on their weight status and level of physical activity by completing the following specific aims:
- conduct a 16-wk randomized trial comparing four different energy balance conditions (n=20/condition); a) physical activity only (+2000 kcal/wk); b) dietary energy restriction only (-2000 kcal/wk); c) combined physical activity / dietary energy restriction (+1000 /- 1000 kcal/wk); and d) wait-list control;
- quantify changes in circulating biomarkers proposed to mediate the anti-carcinogenic effects of energy restriction in response to the intervention conditions; and,
- quantify changes in tissue markers of cell proliferation, survival (TUNEL), and inflammation (prostaglandin-E2) obtained from rectal biopsy in response to the intervention conditions.
The research collaboration outlined in this proposal will establish the feasibility and acceptability of these interventions in our target population, and enable the development of realistic sample-size estimates for the interventions. Formal tests of the effectiveness of different amounts and methods of achieving negative energy balance will be proposed in future R01 proposals (Phase II trials) that will be supported by these preliminary studies.
