Adherence to the Mediterranean diet and incident frailty: Results from a longitudinal study

Objectives: The aim of the current prospective study was to examine the relationship between adherence to the Mediterranean diet and incident frailty.

Study design: 1075 Greek community-dwelling older adults from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD) were included in the present longitudinal analysis.

Main outcome measures: Adherence to the Mediterranean diet was evaluated through the MedDietScore, calculated from the information participants provided on a validated food frequency questionnaire. Frailty was assessed using two multidomain tools: the Frailty Index (FI) and the Tilburg Frailty Indicator (TFI). Analysis of the incidence of frailty as a function of the baseline MedDietScore was performed using Cox proportional hazards models. Additionally, Generalized Estimating Equations (GEE) models were used to explore whether the baseline MedDietScore was associated with the change in the total number of frailty criteria met by participants over time. In testing for a dose-response association between Mediterranean diet and frailty, the MedDietScore was treated either as a continuous variable or as tertiles of low, medium and high adherence to MeDi.

Results: 176 and 131 participants developed incident frailty, as measured with the FI and TFI respectively. Each unit of MedDietScore was associated with a 5% (ΗR 0.95, 95% CI 0.91-0.99, p = 0.012) and 10% (ΗR 0.90, 95% CI 0.86-0.95, p ≤ 0.001) decrease in the risk of incident frailty when measured with the FI and TFI respectively. Compared with participants reporting low adherence to the Mediterranean diet (lowest tertile), those with high adherence (highest tertile) had a 41% (ΗR 0.59, 95% CI 0.38-0.91, p = 0.017) and a 57% (ΗR 0.43, 95% CI 0.27-0.70, p ≤ 0.001) lower risk of incident frailty as measured with the FI and TFI respectively. After excluding from the analyses participants diagnosed with dementia at baseline or follow-up, the same results were obtained: each unit of MedDietScore was associated with a 5% (HR 0.95 CI 0.91-0.99, p = 0.023) and a 10% (HR 0.90 CI 0.86-0.94, p ≤ 0.001) decrease in the risk of incident frailty as measured with the FI and TFI respectively.

Conclusions: The present longitudinal study showed that non-frail community-dwelling older adults with high adherence to the Mediterranean dietary pattern had a significantly lower incidence of frailty.