Effects of 12-Week Dietary Inflammatory Index-Based Dietary Education on Frailty Status in Frail Patients with Colorectal Cancer: A Randomized Controlled Trial

<b>Background</b>: Frailty is common in colorectal cancer (CRC) patients and is associated with poor prognosis and increased mortality. Anti-inflammatory dietary education is a promising and cost-effective strategy for frailty improvement. <b>Methods</b>: A prospective, assessor-blinded, two-arm randomized controlled trial was conducted to assess the effects of a 12-week dietary inflammatory index (DII)-based anti-inflammatory dietary education program on frailty in frail CRC patients. Participants in the intervention group received a DII-based anti-inflammatory dietary education, while the control group received a routine health education. Outcome measurements included the Fried frailty phenotype (FP), DII, plasma inflammatory biomarkers, body mass index (BMI), nutritional status, and quality of life (QoL), which were all assessed at baseline and post-intervention. <b>Results</b>: A total of 86.4% (57/66) of participants completed the follow-up. No statistically significant baseline differences were observed between groups. After the intervention, the intervention group showed significant improvements in DII (<i>p</i> = 0.029), BMI (<i>p</i> = 0.012), mini nutritional assessment (MNA) scores (<i>p</i> = 0.027), and QoL (<i>p</i> = 0.014) compared with the control group. Within-group comparisons revealed significant decreases in frailty status (<i>p</i> = 0.031), DII (<i>p</i> = 0.008), and interleukin (IL)-6 (<i>p</i> = 0.003), and significant increases in IL-10 (<i>p</i> = 0.021), MNA scores (<i>p</i> = 0.010), and QoL (<i>p</i> < 0.001) in the intervention group, with no significant changes in the control group. <b>Conclusions</b>: DII-based anti-inflammatory dietary education can improve the frailty, nutritional status, and QoL of frail CRC patients by modulating systemic inflammation. Given its acceptability and utility, this strategy may be incorporated into routine cancer health education.