Higher dietary acid load is associated with a higher prevalence of frailty, particularly slowness/weakness and low physical activity, in elderly Japanese women

Objective Epidemiologic evidence on the potential effects of dietary acid load on frailty is lacking. This cross-sectional study examined the association between dietary acid load and frailty. Methods This study was based on self-reported data obtained from 2176 Japanese women aged 65-94 years. Dietary acid load was characterized as potential renal acid load (PRAL) and net endogenous acid production (NEAP), based on information on nutrient intake, obtained from a validated brief diet history questionnaire. Frailty score (0-5) was defined as the sum of slowness/weakness (two points), exhaustion (one point), low physical activity (one point), and unintentional weight loss (one point). A score of >= 3 was classified as indicating frailty. Results The prevalence of frailty was 17.9%. After adjustment for potential confounding factors, higher PRAL and NEAP were associated with a higher prevalence of frailty. Adjusted OR (95% CI) for frailty in the highest compared to the lowest quintiles was 1.59 (1.08, 2.34) for PRAL (P for trend = 0.048) and 1.42 (0.98, 2.06) for NEAP (P for trend = 0.03). PRAL and NEAP also showed positive associations with the prevalence of slowness/weakness and low physical activity (all P for trend = 0.03). PRAL (but not NEAP) was positively associated with the prevalence of exhaustion (P for trend = 0.04). There was no association for unintentional weight loss. Conclusions Dietary acid load was positively associated with the prevalence of frailty, particularly slowness/weakness and low physical activity, in elderly Japanese women.