In a randomised, double-blinded placebo-controlled trial among older women, scientists at the University of Texas have found that supplementing the diet with essential amino acids can increase lean body mass and muscle protein synthesis, which could counteract the incapacitating effects of sarcopenia.

Aging can cause a loss of muscle mass, which is known as sarcopenia. This is a disease that is frequently found in the elderly and associated with frailty and disability. This randomised, crossover trial has found that supplementation of essential amino acids (leucine, lysine, isoleucine, valine, threonine, cysteine, histidine, phenylalanine, methionine, thyrosine and tryptophan) can help to increase and maintain muscle mass in elderly people with sarcopenia.

Muscle loss in later life leads to an increased risk of falls, fractures and eventually a loss of independence. This study shows that muscle protein synthesis after consuming essential amino acids is delayed in the elderly, in comparison with younger people. However, the combination of resistance exercise and increasing the intake of essential amino acids can still be a useful strategy to combat sarcopenia.

As people age they experience a gradual decline in muscle mass, strength and function. The aim of this study was to determine whether taking a supplement of essential amino acids regularly could reverse this decline. The study ascertained that supplementation of the diet with essential amino acids (leucine, lysine, isoleucine, valine, threonine, histidine, phenylalanine and methionine) and arginine can improve muscle mass and strength in the elderly.

Branched chain amino acids account for about 35% of the essential amino acids contained in muscle protein. This study shows that endurance exercise at even a moderate intensity can increase the breakdown of muscle protein. However, muscle damage is reduced when branched chain amino acids and arginine are consumed before exercising.