Adherence to the Mediterranean Diet Mitigates Inflammation and Hospital Stay in Frail Elderly Patients: A Moderation Analysis

Abstract

Understanding the interaction between dietary patterns and nutritional status in influencing health outcomes is crucial, especially in vulnerable populations. Our study investigates the impact of adherence to the Mediterranean diet (MD) and nutritional status on inflammatory markers (CRP) and the length of stay (LOS) in hospitalized frail elderly patients. Methods: We conducted two-way ANOVA and multiple regression analysis to evaluate the effects of nutritional status and MD adherence on the CRP levels and LOS in a cohort of 117 frail elderly patients aged 65 years or older. Patients with cancer or acute infection were excluded. Adherence to the MD was assessed using the 14-item PREDIMED questionnaire. Results: Significant interactions were found between nutritional status and MD adherence for both the CRP and LOS. The patients with low-level MD adherence and a poor nutritional status exhibited higher CRP levels and longer hospital stays compared to those with high MD adherence. Specifically, a statistically significant interaction was observed for the CRP (F (1, 113) = 7.36, p = 0.008) and LOS (F (1, 113) = 15.4, p < 0.001), indicating the protective effect of high-level MD adherence. Moderation analysis confirmed that high-level MD adherence mitigates the adverse effects of malnutrition on both the inflammatory response and LOS. Conclusions: These findings highlight the importance of promoting the MD, particularly in malnourished elderly patients, to improve health outcomes and reduce hospitalization duration. Further longitudinal studies are warranted to establish causality and explore the underlying mechanisms.