Summary
This study found that Dutch participants with higher intakes of processed meat and ultra-processed foods during 24 months post-treatment of colorectal cancer had more chemotherapy-induced peripheral neuropathy (CIPN) symptoms. For those that did not receive chemotherapy, there was still an association between processed red meat consumption and CIPN-like symptoms. The researchers also investigated other dietary habits such as fast-food and alcohol consumption and found that a more “healthy” diet was generally associated with better health and quality of life outcomes post cancer treatment. Among the strengths of this study are the use of 7-day protocols and home visits to assess food intake as well as the high follow-up rate, meaning most participants who started the study completed it. A limitation of this study is the low initial response rate of people who completed cancer treatment, which could have led to a biased sample. Another limitation is the possibility of false-positive statistical results due to multiple statistical comparisons made in the study. In conclusion, the authors highlight the association between a high intake of ultra-processed foods and processed meat with increased symptoms of chemotherapy-induced peripheral neuropathy, but also mark that it is not possible to infer causality.
Unhealthy dietary habits can contribute to the development of colorectal cancer (CRC). Such habits may also be associated with post-treatment symptoms experienced by CRC survivors. Therefore, we aimed to assess longitudinal associations of post-treatment unhealthy dietary habits, i.e. intake of ultra-processed foods (UPF), red and processed meat, alcohol and sugar-sweetened drinks, with health-related quality of life (HRQoL), fatigue and chemotherapy-induced peripheral neuropathy (CIPN) in CRC survivors from 6 weeks up to 24 months post-treatment. In a prospective cohort among stage I-III CRC survivors (n 396), five repeated home visits from diagnosis up to 24 months post-treatment were executed. Dietary intake was measured by 7-d dietary records to quantify consumption of UPF, red and processed meat, alcohol and sugar-sweetened drinks. HRQoL, fatigue and CIPN were measured by validated questionnaires. We applied confounder-adjusted linear mixed models to analyse longitudinal associations from 6 weeks until 24 months post-treatment. We applied a post hoc time-lag analysis for alcohol to explore the directionality. Results showed that higher post-treatment intake of UPF and sugar-sweetened drinks was longitudinally associated with worsened HRQoL and more fatigue, while higher intake of UPF and processed meat was associated with increased CIPN symptoms. In contrast, post-treatment increases in alcohol intake were longitudinally associated with better HRQoL and less fatigue; however, time-lag analysis attenuated these associations. In conclusion, unhealthy dietary habits are longitudinally associated with lower HRQoL and more symptoms, except for alcohol. Results from time-lag analysis suggest no biological effect of alcohol; hence, the longitudinal association for alcohol should be interpreted with caution.