Researchers, who conducted a meta-analysis of eight randomized controlled trials, have claimed oral administration of beta-hydroxy beta-methylbutyrate (HMB), a metabolite of leucine, promotes increased lean muscle mass in older adults,. The review, published in European Geriatric Medicine, concluded HMB supplementation is beneficial for improving body composition in older people.
“This review is timely given the growing healthy aging market segment. There is a very strong need among consumers and healthcare practitioners for more information on maintaining muscle mass and function in healthy older adults,” said TSI Group President Larry Kolb.
The review authors, representing the Department of Geriatric Cardiology, The Second Affiliated Hospital of Chongqing Medical University, said when compared with resistance training, dietary interventions for age-related muscle loss appear to be a safe and effective method for alleviating muscle atrophy in older adults with limited mobility or who are at high risk of fall-related injuries. “HMB supplementation is expected to be an important class of these dietary interventions,” they wrote.
They evaluated eight articles including nine randomised, placebo-controlled trials involving participants with a mean age of 65, which used HMB or a combination of substrates with HMB as a primary intervention for no fewer than four weeks, and measured fat-free mass at baseline and post-intervention.
Doses of HMB ranged from 1.5 g/day to 3 g/day. Where used, substrates included combinations of L-arginine, L-glutamine, lysine, ascorbic acid and a carbohydrate. Four of the nine studies included exercise intervention. While most of the studies’ participants were healthy older adults, one involved older adults diagnosed with stage four cancer, another involved healthy older adults who had been on bed rest for 10 days, and one described participants as “ambulatory.”
The researchers’ conclusions were based on the entirety of the scientific evidence evaluated. “The results of the meta-analysis showed that oral HMB supplementation could effectively increase muscle mass, but the change in fat mass was not significant,” they determined. “The increase in muscle mass is due to the net positive balance of protein renewal in the skeletal muscle caused by HMB through stimulation of protein synthesis and attenuation of protein degradation.”