Association of Dietary Intake with the Transitions of Frailty among Japanese Community-Dwelling Older Adults

Background Frailty is a dynamic process, with frequent transitions between frailty, prefrailty, and robust statuses over time. The effect of dietary intake on frailty transitions is unknown. Objective To examine the association between dietary intake and frailty transitions. Design Survey-based retrospective analysis of the National Institute for Longevity Sciences-Longitudinal Study of Aging data. Setting Areas neighboring the National Center for Geriatrics and Gerontology in Aichi Prefecture, Japan. Participants We included 469 prefrail community dwellers aged 60-87 years who participated both in the baseline (2008-2010) and 2-year follow-up (2010-2012) surveys of the National Institute for Longevity Sciences-Longitudinal Study of Aging. Measurements Transitions of frailty were categorized by changes in status from baseline to follow-up: "deterioration (prefrail to frail)," "persistence (persistent prefrail)," and "reversal (prefrail to robust)." Estimated dietary (nutrients and food) intakes assessed by 3-day dietary records in each frailty transition were analyzed with a multivariate-adjusted general linear model after adjusting for sex, age, education, family income, smoking, and chronic disease. Results At the 2-year follow-up, 28%, 7%, and 65% of participants had robust, frail, and pre-frail status, respectively. Among 13 food groups, only milk and dairy product intake was positively associated with frailty reversal even after adjusting for all frailty criteria at baseline. Despite insignificant differences in the estimated mean intakes, the baseline intake of saturated fatty acids, potassium, and vitamin B-1 tended to be the highest in the reversal group. The estimated mean (standard error) for milk and dairy product intake (g/day) was 79.1 (28.6), 129.3 (19.9), and 161.7 (21.7) for the deterioration, persistence, and reversal groups, respectively (P=0.0036, P-trend=0.0019). Conclusions Daily consumption of dairy products may contribute to frailty reversal and frailty prevention among older community dwellers who consume small amounts of dairy products. Other food groups showed no association with frailty status transitions.