Effects of soy protein–rich meals on muscle health of older adults in long-term care: A randomized clinical trial

Abstract

ObjectiveThis study investigated the effects of a soy protein–rich meal intervention on the muscle health of older adults in long-term care facilities. MethodsA 12-week single-center randomized controlled trial with a control-group and open-label design was conducted. Eighty-four older adults from a long-term care facility participated in the study. The chefs at the facility cooked three meals using soy protein–rich recipes designed by dieticians. For 12 weeks, the intervention group participants consumed three meals with 30 g of soy protein (10g/meal) per day, and the control group participants maintained their habitual diets. ResultsThe 84 participants (mean age, 84.9 ± 7.0 years; 61.9% female) were randomly assigned to an intervention group (43 participants) and a control group (41 participants). The intervention group exhibited significant increases in several lean mass indicators, namely soft lean mass (mean, 1.43 kg; 95% confidence interval [CI], 0.20–1.65 kg), skeletal muscle mass (mean, 1.20 kg; 95% CI, 0.43–1.96 kg), appendicular skeletal muscle mass (mean, 0.79 kg; 95% CI, 0.07–1.52 kg), and skeletal muscle index (mean, 0.37 kg/m2; 95% CI, 0.05–0.68 kg/m2) (all p < 0.05). These changes were not observed in the control group (all p > 0.05). Notably, calf circumference decreased significantly in the control group (mean, −0.98 cm; 95% CI: −1.61 to −0.36 cm) but was maintained in the intervention group. The differences in the calf circumference and 6-m walk performance of the two groups were significant (p <0.05). ConclusionsThe 12-week soy protein–rich meal intervention improved the muscle mass and 6-m walk performance of older adults in a long-term care facility.