Assessment of the acidifying potential of diet and sarcopenia in individuals 50 years of age or older: a cross-sectional study

A prolonged acid-base imbalance resulting from the diet can exert an influence on the decrease in muscle mass and consequent occurrence of sarcopenia, especially in older adults. Therefore, the aim of the present study was to investigate the potential association between an acidogenic diet and sarcopenia. A cross-sectional study was conducted with individuals of both sexes ≥ 50 years of age. Data were collected on clinical and sociodemographic characteristics and physical activity level. The SARC-F questionnaire was used to assess the risk of sarcopenia. Muscle strength (dynamometry) and muscle function (walking speed test) were also determined, as recommended by the European Working Group on Sarcopenia in Older People. Dietary intake, dietary acid load (potential renal acid load formula-PRAL), and urinary pH were assessed. Anthropometric data were collected. Body composition was estimated using electrical bioimpedance. The variables were compared using the chi-square test, Fisher’s exact test, the Student’s t-test, and the Mann-Whitney test. In multiple comparisons between pairs of groups, p-values were obtained using a two-tailed bootstrap approach adjusted using the Holm method. For the analysis in tertiles, the 33rd and 67th percentiles were calculated. Associations between exposure variables and the presence of sarcopenia were expressed as prevalence ratios (PR) and respective 95% confidence intervals (CI). Eighty-two individuals were analyzed, with a predominance of women (91.5%) and mean age of 64.17 ± 7.42 years. The prevalence of sarcopenia was 30.5%. Higher PRAL tertiles were associated with the risk of sarcopenia (p = 0.009) and body mass index (p = 0.032). Sarcopenia was associated with age ≥ 65 years (p = 0.009), lower consumption of foods that are sources of protein with high biological value (PR = 2.47; 95%CI:1.32–4.63), and acidic urinary pH (PR = 1.94; 95%CI:1.03–3.63). The occurrence of sarcopenia was higher in older adults whose diets had higher acidifying potential and who consumed less protein of high biological value.