A Pilot Study on the Effects of Medium-Chain Triglyceride-Enriched Oral Nutritional Supplementation on Nutritional Status, Physical Function, and Cognitive Function in Older Facility Residents

Background Malnutrition is associated with increased morbidity and all-cause mortality, and the proportion of undernourished individuals tends to increase with age. The Global Leadership Initiative on Malnutrition (GLIM) proposed a consensus in 2019 defining malnutrition based on criteria including weight loss, reduced muscle mass, and low body mass index (BMI). The purpose of this study was to evaluate whether daily supplementation with medium-chain triglycerides (MCTs), provided in the form of snacks, improves or maintains nutritional status in older adults who are malnourished or at risk of malnutrition, and to compare changes in muscle strength and physical function between the MCT-supplemented group and the control group. Additionally, this study aimed to assess the feasibility of incorporating MCT supplementation into routine nutritional care at long-term care facilities. Materials and methods The study's participants were older residents of long-term care health facilities. The design was a pre-post comparison at a single facility. Participants were divided into a medium-chain triglycerides (MCT)-supplemented group (intervention group) and a group receiving regular meals (control group). The intervention group consumed a snack containing MCTs (135-136 kcal, 0.4 g protein) in addition to the diet provided at the facility. BMI, anthropometric measurements, the type of diet being consumed, grip strength, nutritional indicators, and cognitive function were also measured before initiation, 3 months after intake, and 5 months after intake. Results In the intervention group, BMI increased from 18.8 ± 2.2 kg/m² at baseline to 19.7 ± 2.3 kg/m² after 5 months (t=-3.629, p=0.002, 95% CI (-1.468 - -0.381)); BMI increased in 14/16 participants (87.5%). In the control group, BMI decreased slightly from 20.5 ± 2.8 kg/m² at baseline to 20.2 ± 2.7 kg/m² at 5 months (t=-0.767, p=0.476, 95% CI (-0.780 - 1.559)). Grip strength in the intervention group increased from 9.9 ± 3.9 kg at baseline to 11.1 ± 5.2 kg after 5 months (t=2.192, p=0.049, 95% CI (0.033 - 2.342)).MNA-SF scores improved in both the intervention group (from 7.4 ± 1.6 to 9.7 ± 1.4) and the control group (from 7.2 ± 2.1 to 9.6 ± 1.6), making it difficult to determine group-specific effects on nutritional status. No significant changes were observed in cognitive function in either group. Conclusion This study showed that providing one snack containing MCTs (10 g/day) daily for 5 months, in addition to regular meals, led to improvements in BMI and grip strength in undernourished older adults residing in long-term care facilities. Although MNA-SF scores also improved, the similar degree of improvement observed in both the intervention and control groups made it difficult to determine the specific contribution of MCT supplementation to overall nutritional status. Cognitive function did not show significant changes, which may be due to the short intervention period and limited sample size. Nevertheless, the observed improvements in physical function suggest that MCT-containing snacks may be a useful nutritional strategy for supporting the health of older adults. Further large-scale studies are needed to clarify the effects on cognitive function and to better distinguish the independent impact of MCT supplementation on nutritional outcomes.