Dietary supplementation with the amino acid leucine increased muscle volume and strength, lowered inflammation and improved the overall well-being of patients with moderate to severe cerebral palsy (CP), a study has found.
The study, “Leucine Supplementation Increases Muscle Strength and Volume, Reduces In ammation, and Affects Wellbeing in Adults and Adolescents with Cerebral Palsy,” was published in The Journal of Nutrition.
Studies suggest that feeding problems, lower physical activity levels, and low-grade inflammation in those with CP contribute to the impaired capacity of muscle cells to make new proteins. Over time, this may lead to shrinkage (atrophy) and loss of muscle tissue.
Taking the amino acid leucine — one of the building blocks of proteins — has been shown to stimulate protein production and enhance muscle mass. In those with CP, leucine supplementation can boost the body’s metabolism, potentially minimizing health risks associated with being sedentary and muscle atrophy.
However, to the researchers’ knowledge, there haven’t been any studies on how leucine supplementation might affect the well-being of CP patients.
To address this, these researchers in the U.K. and Australia conducted a clinical study to determine if daily leucine supplementation for a period of 10 weeks would improve muscle function and the well-being of patients with moderate to severe CP.
The study (NCT03668548) enrolled 24 adolescents and young adults with CP who were randomly divided into two groups: a leucine supplementation group and a control group.
Those in the leucine supplementation group received daily L-leucine (192 mg/kg) dissolved in a mixture of water (300 ml) and fruit concentrate to mask the taste, while those in the control group received the same drink without leucine. To control for external sources of leucine, all participants were asked to keep a diet diary.
Muscle strength (elbow flexor muscle contraction), muscle volume, the levels of C-reactive protein (CRP) in the blood (a marker of inflammation) and patient well-being (assessed by a self-reported questionnaire) were evaluated before and after the 10-week supplementation period.
Three of the 24 participants withdrew from the study due to personal reasons, inability to take the supplement, and non-compliance with the protocol. In total, 10 participants in the leucine group and 11 in the control group completed the study.
Food diary analysis from 19 study participants (eight from the leucine and 11 from the control group) showed that the total macronutrient and energy intake was similar between both groups, excluding the interference of other diet components.
After 10 weeks, those receiving leucine supplementation had a significant increase in muscle strength (25.4%) and muscle volume (3.6%). In contrast, no significant changes in muscle strength or volume were found among those in the control group.
Leucine supplementation also decreased inflammation, lowering the levels of CRP in the blood by 59.1% (from 4.7 to 1.9 mg/L). No significant changes in the levels of CRP were found among patients from the control group.
No changes in metabolism, rest energy spending, or body fat composition were seen in any of the groups.
Patients in the leucine supplementation group reported improvements in mood and general well-being, as well as a decreased muscle soreness and stress.
Overall, leucine supplementation “provided a variety of benefits to young adults and adolescents with moderate to severe CP,” the researchers wrote.
“The improved well being of the CP group that consumed leucine also highlights its alternative roles and capacity to improve the quality of daily living,” they added.