Lack of Adherence to the Healthy Eating Index and its Association with Frailty in the Elderly: A Systematic Review and Dose-Response Meta-Analysis of Epidemiologic Studies with GRADE Assessment

Context: Adherence to the Healthy Eating Index (HEI) diet is considered a dietary pattern that can improve overall health. Objective: Numerous studies have attempted to assess the relationship between adherence to the HEI diet and frailty. In this review, a dose-response meta-analysis of epidemiological investigations was conducted to evaluate the relationship between HEI adherence and frailty. Data Sources: Following the PRISMA guidelines, a systematic literature search was conducted in EMBASE, the Institute for Scientific Information (ISI), MEDLINE (PubMed), Scopus, and Google Scholar to September 2024. The quality of the available evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. Data Extraction: Eight observational studies examining the association between HEI and frailty were identified for inclusion. Data Analysis: Analysis of 8 observational investigations (3 cohort and 5 cross-sectional) with 89 860 individuals and 13 242 cases of frailty revealed that highest vs lowest adherence to HEI was significantly associated with a 34% reduced odds/risk of frailty in the elderly (OR = 0.66; 95% CI: 0.54, 0.81; I-2: 93.9%, PQ-test < .001). Subgroup analysis based on physical activity adjustment showed a significant decline in both subgroups of studies, both with adjustment (OR = 0.61; 95% CI: 0.38, 0.98) and without adjustment (OR = 0.62; 95% CI: 0.42, 0.90). Sensitivity analysis revealed that excluding 1 investigation from the analysis could resolve between-studies heterogeneity in the cohort (OR = 0.68; 95% CI: 0.53, 0.87; I-2: 47.1%, PQ-test = .15) and cross-sectional studies (OR = 0.51; 95% CI: 0.38, 0.69; I-2: 32.3%, PQ-test = .22). Dose-response analysis revealed that each 25-point increment in HEI adherence was related to an 8% decline in frailty odds/risk (OR = 0.92; 95% CI: 0.88, 0.96). A significant nonlinear association was additionally found; the declining slope of the curve was relatively steeper for HEI scores above 45. The evidence certainty was rated as high. Conclusion: Higher adherence to HEI was inversely associated with odds/risk of frailty in the elderly, in a dose-response fashion. Systematic Review Registration: PROSPERO registration No. CRD42023407984).