Low-calorie diet rejuvenates aging muscles
A low-calorie diet is being studied as an effective method of increasing the life expectancy of model organisms. A number of studies have demonstrated its ability to reduce the risk of developing diseases of the cardiovascular system and some other diseases, as well as improve overall health. In their latest work, Taiwanese researchers from Chang Gung University demonstrated that a low-calorie diet has a beneficial effect on the condition of muscle tissue, improving its metabolism and muscle mass in middle age, which is a very important period for the body.
It is believed that a low-calorie diet has a protective effect on muscle cells, improving their ability to use antioxidants and avoid damage caused by free radicals, as well as improving the functioning of these cells. Although studies on animals of different ages devoted to the study of the effects of a lifelong low-calorie diet have brought contradictory results, the data obtained in recent studies indicate that age can influence the effect that a low-calorie diet has on individuals. The authors hypothesized that, given the ability of a low-calorie diet to trigger the reprogramming of metabolism, the greatest positive effect can be obtained when exposed to aging muscles, which are characterized by metabolic disorders at the cellular level.
They devoted their work to the study of two signaling mechanisms that ensure energy production in muscle cells – glycolysis (rapid incomplete breakdown of carbohydrates) and mitochondrial oxidative phosphorylation (complete breakdown of nutrient molecules). To do this, the authors observed the condition of young rats and middle-aged animals kept on a normal or low-calorie diet. During a 14-week study, the diet of rats on a low–calorie diet was cut by 10% during the first week, by 25% during the second week and by 40% during the remaining 12 weeks. At the end of 14 weeks, the researchers analyzed changes in the muscle tissue of the animals.
The obtained results demonstrated the dependence of the effects of a low-calorie diet on age. While young animals kept on a low-calorie diet had a decrease in muscle mass, in middle-aged animals, a decrease in the nutritional value of the diet improved the metabolism of muscle tissue and normalized muscle mass. This was due to a slowdown in the rate of glycolysis in muscles and an increase in the dependence of muscle cells of middle-aged rats on oxidative phosphorylation.
Article by Chiao-nan (Joyce) Chen et al. Late-onset Caloric Restriction Alters Skeletal Muscle Metabolism by Modulating Pyruvate Metabolism is published in the American Journal of Physiology – Endocrinology And Metabolism.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the American Physiological Society:
Caloric Restriction: A Fountain of Youth for Aging Muscles?
23.04.2015