Purpose: To review the literature focusing on the effects of dietary behavioural changes on cancer patients' health-related quality of life (HRQOL).
Methods: Relevant databases were searched for studies that report the relationship between dietary changes and HRQOL of people with cancer and synthesized and systematically reviewed the available evidence. Papers were assessed for methodological quality, and the themes identified were summarized.
Results: The selected studies included only randomized control trials, which target changes in diet. Twelve studies were identified, which focus on the association between lifestyle changes that included changes in diet and HRQOL among cancer patients. Results have been mixed, and dietary changes have been shown to partly affect HRQOL, but other factors seem to be important as well in defining that relationship. Moreover, cancer groups with higher survival rates (prostate, breast, colorectal) seem to benefit more from dietary changes, while different HRQOL constructs are affected with no clear indication of directional benefits on physical or mental health.
Conclusions: Even though there are some indications of a direct relationship between dietary changes and HRQOL, further research should establish which areas of HRQOL are directly affected. Perhaps, nutritional changes in future interventions can be isolated in order to identify a potential direct relationship with HRQOL.