Malnutrition and dietary interventions in colorectal cancer patients

There is strong evidence for the link between diet and the risk of developing colorectal cancer (CRC). The role of diet after diagnosis remains unclear. Moreover, CRC patients may experience nutritional problems leading to malnutrition and depletion of fat-free mass (FFM). PG-SGA is one of a few nutritional assessment tools targeting all dimensions of malnutrition, including depletion of muscle. However, the knowledge about its ability to identify low FFM is scarce. The overall aims of this thesis were to develop and establish a randomized controlled trial (RCT) with individualized nutrition intervention and to evaluate the ability of the PG-SGA to identify low FFM. The CRC-NORDIET study was established in 2012. In this study, we investigate whether a diet in accordance with the Norwegian food-based dietary guidelines will improve long-term disease outcomes and survival in CRC patients, through dampening of inflammation and oxidative stress. The intervention group (n=250) receives an intensive dietary intervention lasting for 1 year, whereas the controls (n=250) receives standard care. Both groups receive general advice on physical activity. Patients are followed up 15 years after baseline. The thesis included data from the ongoing CRC-NORDIET study. Nutritional status was assessed with PG-SGA, and FFM was analyzed by the use of bioelectrical impedance analysis (BIA) and Dual energy x-ray absorptiometry (DXA). Low FFM was identified in 29 % of these patients. Interestingly, only half of the patients with low FFM were evaluated as “malnourished” by PG-SGA. The remaining were evaluated as “well nourished”. Estimation of FFM by BIA showed good agreement compared to the reference method DXA. Our findings indicate that PG-SGA did not identify the patients with low FFM with sufficient sensitivity, and that the method should be accompanied by BIA. The ongoing CRC-NORDIET study will contribute with novel knowledge regarding the role of diet for CRC patients