A 12-Week Structured Antioxidant-Focused Dietary Intervention Improves Cognitive Function and Oxidative Stress Biomarkers in Lung Cancer Patients with Cancer-Related Cognitive Impairment: A Randomized Controlled Trial

Patients with lung cancer are at increased risk of developing cancer-related cognitive impairment (CRCI), and oxidative stress may contribute to its development. We conducted an assessor-blinded randomized controlled trial to evaluate whether a 12-week antioxidant-focused dietary intervention improved cognitive function, oxidative stress biomarkers, and quality of life (QoL) in lung cancer patients with CRCI. One hundred participants were randomized to standard dietary counseling or an antioxidant-focused dietary intervention. Continuous outcomes were assessed at baseline and week 12 and analyzed using linear mixed-effects models under the intention-to-treat principle. The mean age was 66.10 ± 5.39 years, and 78.0% of participants were male. Ninety-one participants completed the week-12 assessment. Participants receiving the intervention demonstrated greater increases in Montreal Cognitive Assessment scores (β = 2.626; 95% CI: 0.825, 4.427; p = 0.005), dietary oxidative balance score (β = 2.292; 95% CI: 0.656, 3.928; p = 0.006), and physical and mental QoL component scores than those in the control group (p < 0.05). In the complete-case analysis (n = 91), the proportion meeting CRCI criteria was lower in the intervention group (60.0% vs. 93.5%; p < 0.001). Biomarker analyses showed increases in glutathione and superoxide dismutase and a reduction in malondialdehyde in the intervention group (p < 0.05). The intervention demonstrated a large effect on cognitive function (Cohen's d = 0.84), supporting antioxidant-focused dietary intervention as a promising supportive-care strategy for managing CRCI in lung cancer patients.