The combined supplementation of medium-chain triglycerides (MCTs), l-leucine-rich amino acids, and cholecalciferol was previously shown to increase muscle strength and function in frail elderly individuals.

We examined whether treatment with MCTs alone is sufficient to increase muscle strength and function and activities of daily living (ADL) in such individuals.

We enrolled 64 elderly nursing home residents (85.5 ± 6.8 y) in a 3-mo randomized, controlled, single-blinded intervention trial. The participants were randomly assigned to 3 groups: the first group received supplemental l-leucine (1.2 g) and cholecalciferol (20 μg) enriched with 6 g/d of MCTs (LD + MCT group) as a positive control, the second group received 6 g/d of MCTs (MCT group) as a target, and the third group received 6 g/d of long-chain triglycerides (LCT group) as a negative control. Changes in muscle mass, strength, function, and ADL were monitored 4 times: at baseline, at 1.5 and 3 mo after initiation of the intervention (intervention), and 1.5 mo after termination of the intervention (washout).

The 64 participants randomly assigned to the 3 groups were included in an intention-to-treat analysis. Forty-eight participants completed the study and were included in a per-protocol analysis. At 3 mo, participants in the MCT group had a 48.1% increase in 10-s leg open and close test performance [intention-to-treat adjusted means: MCT 2.28 n/10 s (1.37, 3.19) compared with LCT -0.59 n/10 s (-1.52, 0.35), P < 0.05], a 27.8% increase in a 30-s repetitive saliva swallowing test [MCT 0.5 n/30 s (0.1, 1.0) compared with LCT -0.5 n/30 s (-0.9, 0.0), P < 0.05], and a 7.5% increase in Functional Independence Measure score, a questionnaire for assessing ADL [MCT 5.6 points (1.3, 9.9) compared with LCT -6.6 points (-11.3, -2.0), P < 0.05].