Nutritional literacy as a potential moderator of the intrinsic capacity–frailty relationship in older adults: a cross-sectional study

Abstract

Abstract Intrinsic capacity (IC) and frailty are two interrelated constructs that shape the functional trajectory of aging. Although both are influenced by multiple lifestyle and health-related factors, limited evidence exists on how nutritional literacy (NL), the nutrition-specific knowledge and skills required making informed dietary decisions, may modify this relationship. This cross-sectional study was conducted in 2024 among 250 community-dwelling older adults aged 60 years and above. Data were collected using validated tools: the WHO ICOPE screening tool for IC, the FRAIL scale for frailty, and the 28-item NL Scale. Descriptive statistics, Spearman correlations, and hierarchical multiple regression analyses were used to examine NL as a potential moderator in the IC–frailty relationship. Participants had a mean age of 67.13 ± 6.23 years, and 59.2% were female. The mean IC score was 3.13 ± 1.16 and the mean frailty score was 2.05 ± 1.16. IC correlated negatively with frailty (r=–0.326, p < 0.001), and NL showed a similar inverse correlation (r=–0.199, p = 0.002). Hierarchical regression indicated that both IC (β=–0.25, p < 0.001) and NL (β=–0.16, p = 0.008) significant associations with frailty. The interaction term (IC × NL) was significant (β=–0.29, p < 0.001), explaining an additional 7% of the variance. Simple slope analysis showed that IC was strongly protective against frailty in participants with insufficient (β=–0.199, p < 0.001) or borderline NL (β=–0.20, p = 0.027), but not in those with sufficient NL (β=–0.076, p = 0.633). These findings are consistent with a pattern where that NL shapes how IC associated with frailty, acting as a compensatory factor when literacy is high and a vulnerability amplifier when it is low. Enhancing NL may therefore strengthen resilience against frailty, especially in older adults with declining IC, offering a low-cost strategy for sustaining functional independence in later life.