A six-month pilot study compared BCAA supplementation with soy protein intake to assess the effects of amino acid intake on physical (muscle) strength and mental health parameters.
BCAA was reported to improve knee muscle strength, although there was no change in skeletal mass, and was associated with reduced depressive states by stimulating the production of tryptophan, a precursor to serotonin. Meanwhile, soy protein reduced low-density serum lipoprotein concentrations, leading to significant improvements in muscle strength.
Sign up nutrients, the authors comment: “Findings may be valuable for improving muscle function and managing co-morbidities in older individuals with T2D.”
Sarcopenia is characterized by decreased skeletal muscle mass, muscle strength, and physical performance due to insufficient dietary protein. These symptoms are exacerbated in patients with T2D, where up to 20% exhibit lower knee extension strength and are at risk for an accelerated decline in lower muscle strength, the authors explain.
“About 30-50% of community-dwelling older adults consumed less than the recommended amount of protein, as did older people with diabetes. In addition, it is difficult for the elderly to change dietary habits to achieve the recommended dietary protein intake.”they say.
Boosting protein synthesis through BCAA supplementation is key to improved muscle function, as shown in a number of studies and therapeutic treatments, but few studies have assessed the results on skeletal muscle in elderly patients with T2D.
Thirty-six elderly participants (aged 65 to 80 years) with T2D were recruited from an outpatient clinic for the 24-week randomized study and assigned to the BCAA or soy protein (comparator) group.
The BCAA group consumed an amino acid supplement containing 4g leucine, 2g valine and 2g, isoleucine and 36 kilocalories (kcal) of energy. The soy protein formula contained 7.5 g of protein and 40 kcal of energy, although the Japanese manufacturer (Meiji Co.) would not disclose the amino acid content.
Participants were required to perform aerobic exercise and “comprehensive” resistance training, including stretching, two sets of 10 reps of thighs for each leg, and two sets of 10 squats at least three times a week.
A Clinical Research Coordinator (CRC) was assigned to monitor supplement intake once a week and ensure compliance with the exercise program.
Primary outcomes were changes in skeletal muscle mass, while secondary outcomes focused on knee muscle and grip strength, glucose metabolism, lipid metabolism, neuropsychological performance, depression and motivational states, tryptophan metabolites, renal function, and urinary albumin excretion (UAE).
Physical and Mental Results
Participants in the BCAA group”showed a tendency” to increase knee extension muscle strength and this result improved significantly after soy protein intake. There was no improvement in skeletal muscle mass and no changes in glycemic control or insulin resistance.
A remarkable, but unexpected finding, showed that BCAA significantly reduced knee extension muscle endurance – possibly due to reduced response of peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1a) – despite increases in muscle strength. of knee extension, although there was no change in endurance with soy protein.
“That is a new finding in terms of amino acid or protein supplementation and skeletal muscle endurance in the elderly,” state of the authors.
They add that “the cause of the varying effects of BCAA or soy protein supplementation on knee extension strength and endurance remains to be elucidated”.
BCAA supplementation significantly increased serum tryptophan levels and improved depressive symptoms. The researchers hypothesize that supplements may have a decreased serum kynurenine and kynurenine-to-tryptophan ratio, inhibit kynurenine uptake, and/or increase glutamine or glutamic acid in the brain.
Finally, supplementation with both products was considered acceptable for the demographic group of participants (elderly patients with T2D).
Study limitations include the absence of a control group, possible effects of COVID-19 on participants’ activity (although done was detected), non-adherence to uncontrolled resistance training, and homogeneous groups, which may have influenced the results.
Nevertheless, the findings identified favorable results with amino acid supplementation on muscle strength in the elderly with T2D and demonstrated safety with regard to insulin resistance and renal function.
‘Effects of branched-chain amino acids on skeletal muscle, glycemic control and neuropsychological performance in the elderly with type 2 diabetes mellitus: an exploratory randomized controlled trial’
Takaaki Matsuda, Hiroaki Suzuki 1, Yoko Sugano 1, Yasuhiro Suzuki, Daisuke Yamanaka, Risa Araki, Naoya Yahagi, Motohiro Sekiya, Yasushi Kawakami, Yoshinori Osaki, Hitoshi Iwasaki, Koichi Hashimoto, Shin-Ichiro Takahashi, Yasushi Hada and Hitoshi