The inflammatory potential of diet in older adults: its relationship with sarcopenia components and nutritional status - a multicentre cross-sectional study

Dietary inflammation has emerged as a key modifiable factor influencing age-related conditions such as malnutrition and sarcopenia, which significantly impact functional capacity and quality of life in older adults. This study aims to evaluate the relationship between the Dietary Inflammatory Index (DII) and nutritional status, as well as sarcopenia components such as muscle mass and strength, in older adults. This multicentre, cross-sectional study involved 347 older adults (mean age 70.3 ± 4.09 years, 59.4% women) registered with four educational family health centres in İzmir, Türkiye. Data were collected via face-to-face interviews. Nutritional status was assessed using the Mini Nutritional Assessment-Short Form (MNA-SF) and DII was calculated based on three-day food consumption records. Sarcopenia was assessed according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. Muscle strength was measured using a hand dynamometer and muscle mass using bioelectrical impedance analysis (BIA). Statistical analyses included independent t-tests, chi-square tests, ANOVA, Spearman correlation analysis, and multivariate logistic regression models. All analyses were performed using SPSS version 16.0, and a p-value < 0.05 was considered statistically significant. The prevalence of malnutrition or risk of malnutrition was 20.7%, and the prevalence of probable sarcopenia was 18.4%. The mean overall DII score was −1.7 ± 1.57 (range: −4.79 to 3.30). Participants were divided into four quartiles according to their DII scores: Q1 < −2.73; Q2, −2.73 to −2.14; Q3, −2.14 to − 0.98; and Q4, −0.98 to +3.30. DII scores were significantly higher in individuals who were malnourished or at risk of malnutrition than in those with normal nutritional status (−1.38 ± 1.50 vs. −1.79 ± 1.58), although no significant correlation was observed between DII and MNA-SF scores ( p > 0.05). DII was weakly positively correlated with SARC-F scores and weakly negatively correlated with handgrip strength and muscle mass. The mean DII score was significantly higher in individuals with probable sarcopenia than in those without probable sarcopenia (−1.21 ± 1.67 vs. −1.82 ± 1.52, p = 0.005). In the model adjusted for BMI and smoking status, participants in both the second and third DII quartiles had significantly higher odds of probable sarcopenia compared with those in the lowest quartile (Q2: OR = 2.40, 95% CI: 1.07–5.38, p = 0.033; Q3: OR = 2.38, 95% CI: 1.06–5.32, p = 0.035). Participants in the highest DII quartile also had higher odds of malnutrition or risk of malnutrition (OR = 2.97, 95% CI: 1.20–7.24, p = 0.018). However, these associations were no longer statistically significant after further adjustment for age, sex, marital status, and education. Higher DII scores were associated with poorer nutritional and muscle-related outcomes in older adults, with several associations being more evident among women. However, associations with probable sarcopenia and malnutrition risk were attenuated after further adjustment for sociodemographic factors. These findings suggest that dietary inflammatory potential may be relevant to nutritional and muscle health in older adults. Longitudinal studies are needed to clarify the direction of these associations and their potential clinical implications.