Fat free mass is inversely associated with mortality. This relates in part to the fact that as people age muscle mass naturally decreases, which is in part caused by the natural reduction in hormones including growth hormone, testosterone and insulin like growth factor, that occurs with ageing. Therefore the older someone becomes the closer they are to death, and therefore the lower their muscle mass is likely to be. In addition, the elderly are more likely to become ill than the young, and illness can cause a decrease in muscle mass and this strengthens the positive association between the two factors. That being said, improvements in skeletal muscle mass in the elderly have been shown to improve the quality of life because improvements in body composition bring health benefits including improved flexibility, improved mobility, improved endurance as well as changes to many biochemical parameters. Strategies to improve skeletal muscle and physical strength are therefore of interest to nutritional and health researchers.
Improving the body composition in the elderly has important health consequences. In particular, improvements in skeletal muscle mass can bring real World improvements in the quality of life. Physical activity is important in this process, but improvements in strength, flexibility and other beneficial physiological changes can be accelerated with improved nutrition. In particular, higher protein diets that posses adequate amount of essential amino acids, may work synergistically with physical activity. Vitamin D is an important consideration because the elderly have been identified as an at risk group who have an increased risk of a poor vitamin D status. The elderly are much more likely to be institutionalised or confined inside, than younger individuals, and this may explain the poor vitamin D status of the elderly in general. Vitamin D supplements may provide this group with adequate vitamin D intakes without the need for increasing exposure to sunlight. Adequate intakes of vitamin D may have important downstream hormonal effects that facilitates skeletal muscle growth.
High protein diets may have particular benefits at increasing fat free mass in the elderly. For example, in one study researcher administered 22 gram of whey protein, 10.9 grams of essential amino acids including 4 grams of leucine, as well as 2.5 μg of vitamin D (100 IU) to sarcopenic elderly subjects. There was also a physical activity programme. The results showed that the subjects consuming the supplements had 1.7 kg greater increases in fat free mass compared to those performing the physical activity but not taking the supplements. The increase in fat free mass was made up in part by an increase in skeletal muscle, and this was accompanied by improvements in the ability to perform daily tasks. In the supplement group there was also an increase in handgrip strength, a decrease in inflammation and an increase in insulin like growth factor. Taken as a whole these results suggest that protein and vitamin D may cause a significant increase in anabolism, which results in the generation of skeletal muscle mass.
Eat Well, Stay Health, Protect Yourself
RdB
