Diet Quality and Incident Frailty in Adults 65 Years or Older: The Israeli Longitudinal Study on Aging

Objective: To prospectively examine the association between diet quality and frailty incidence in the oldest-old age group. Methods: We studied an older adult (65+ years) cohort participating in the Israeli National Health and Nutrition Survey of Older Adults in 2005-2006 (T1 [N=1799]). Survivors of T1 were contacted, and between 2017 and 2019, an extensive interview and a functional assessment were conducted (T2) of 604 past participants. A 24-hour dietary recall, assessed at T1, was used to calculate the Healthy Eating Index (HEI-2015) score. A frailty index based on an accumulation of deficits, including clinical, functional, and cognitive measures, was computed. Frail participants at T1 were excluded from the analysis. Logistic regression models were constructed to assess the association of HEI-2015 score with frailty incidence. Inverse probability weighting was used to minimize selection bias due to attrition. Results: Of the 479 T2 participants analyzed (mean [SD] age, 84 [5] years; 50% women), 225 (46%) were classified as frail. Frail participants were older, were less educated, and had a lower household income and a higher comorbidity burden at baseline than non-frail participants. After adjustment for sociodemographic and lifestyle factors, a higher HEI-2015 score was associated with decreased odds of incident frailty (odds ratio, 0.57 [95% CI, 0.35 to 0.91] for the upper tertile and 0.66 [95% CI, 0.42 to 1.06] for the middle tertile compared with the lower tertile; P_trend=.02). Conclusion: In this cohort study of oldest-old participants, improved diet quality was inversely associated with frailty incidence in a dose-dependent manner.