Prospective Associations of Diet Quality With Incident Frailty in Older Adults: The Health, Aging, and Body Composition Study

OBJECTIVE: To examine associations of diet quality indicators with 4-year incidence of frailty in community-dwelling older adults. DESIGN: Prospective cohort study. SETTING: Health, Aging, and Body Composition Study, United States. PARTICIPANTS: Community-dwelling men and women, aged 70 to 81 years in 1998 to 1999 (first follow-up, present study's baseline; n = 2154). MEASUREMENTS: At first follow-up, dietary intake over the preceding year was assessed with a food frequency questionnaire. Indicators of diet quality include the Healthy Eating Index (categorized as poor, medium, and good), energy intake, and protein intake (a priori adjusted for energy intake using the nutrient residual model). Frailty status was determined using Fried's five-component frailty phenotype and categorized into “robust” (0 components present), “pre-frailty” (1 - 2 components present), or “frail” (3-5 components present). Cox proportional hazards analysis was used to examine associations of the diet quality indicators with 4-year incidence of (1) frailty and (2) pre-frailty or frailty. Competing risk analysis was used to examine associations with frailty by accounting for competing risks of death. RESULTS: During the 4-year follow-up, 277 of the 2154 participants, robust or pre-frail at baseline, developed frailty, and 629 of the 1020 participants, robust at baseline, developed pre-frailty or frailty. Among the robust and pre-frail, after adjustment for confounders including energy intake, those consuming poor- and medium-quality diets had a higher frailty incidence than those consuming good-quality diets (hazard ratio [HR] = 1.92 [95% confidence interval {CI} = 1.17-3.17] and HR = 1.40 [95% CI = 0.99-1.98], respectively). No associations for energy or protein intake were observed. Competing risk analyses yielded similar results. Among the robust, those with lower vegetable protein intake had a higher “pre-frailty or frailty” incidence (per −10 g/d: HR = 1.20; 95% CI = 1.04-1.39). No other associations were observed. CONCLUSION: Poorer overall diet quality and lower vegetable protein intake may increase the risk of becoming frail in old age. We found no association for intakes of energy, total protein, or animal protein. J Am Geriatr Soc 67:1835–1842, 2019