How does age affect human muscles?
In old age, the human body breaks down, which leads, for example, to the weakening of muscles and cognitive functions. Researchers have now found that the previously inevitable appearance of muscle weakness in old age can be prevented.
The researchers at Manchester Metropolitan University found in their investigation that muscle weakness occurring at an advanced age can be prevented. The doctors published the results of their study in the journal "Journal of Physiology".
Muscle weakness can lead to dangerous falls
In their current investigation, the experts found out what causes muscle weakness to occur in older people. This knowledge can apparently be used to stop the process. Most people's leg muscles get smaller as they get older, which means that the legs are no longer able to support the weight of the person concerned. This can lead to serious falls or various everyday restrictions. Until now, however, it was not known why this process occurs or how it can be slowed down or stopped.
Older people have fewer nerve connections
People aged 75 and over have 30 to 50 percent fewer nerves that control the muscles in their legs. As a result, large parts of the muscle remain separated from the nervous system, which acts as a communication link to the brain. Without this connection, the muscle areas atrophy and die.
Results confirm older study
Previous research showed similar results in a small group of people who appeared to have only a few surviving nerves that affected the foot muscle, explains study author Dr. Mathew Piasecki, who has now started a job at the University of Nottingham. The results were then found in old women and many medical professionals were very skeptical. However, similar effects have now been observed in many men. Some very old muscles were identified that only had a few dozen nerves. In young adults, there are hundreds of nerves in these muscles, the experts explain.
Doctors use MRI scans and electromyography
The researchers used MRI scans to examine muscle tissue in more than 200 men more closely. Electromyography was then performed to detect the electrical activity through the muscle. The number and size of the surviving nerves of the muscle fibers should be estimated. The MRI scans showed how muscles break down with age when nerve connections die, the scientists say. The researchers also found that the nerves in healthy muscles can create new branches to save muscles with few nerve connections. Regular training can support this process, the doctors suspect.
Results could help people with muscle weakness
The challenge now is to find ways to increase the success of nerve branching. In this way, muscle fibers can be saved and the number of older people who suffer from low muscle mass and muscle weakness is reduced, explains study author Professor Jamie McPhee from Manchester Metropolitan University.
More research is needed
The results of the study help explain why the muscles decrease with age. This understanding could help in the search for effective countermeasures in the future. For example, researchers at King’s College London and the University of Birmingham recently discovered that cycling slows down aging and boosts the immune system. These results contradicted the assumption that age automatically leads to inevitable physical breakdown. Movement is still the best medicine. (as)