For muscle strength to be maintained with age, the 'garbage' in the cells must be shed, says a new study.
Researchers arrived at their conclusions by examining mice, which lacked a gene required for degradation and recycling inside cells, a process known as autophagy. The mice showed considerable muscle atrophy and muscle weakening that deteriorated as they aged.
Marco Sandri from the University of Padova, Italy said: "If there is a failure of the system to remove what is damaged, and that persists, the muscle fiber isn't happy."
Damaged and misfolded proteins, dysfunctional mitochondria, distended endoplasmic reticulum and free radicals keep on adding up inside the cells. In the end, some of these muscle cells degenerate and "the muscles become weaker and weaker with age."
Sandri said the muscle atrophy seen in mice showed some similarity with some forms of some muscle-wasting diseases.
He added: "We thought if you reduced autophagy it might protect against atrophy...Instead, it's the opposite. We realized, OK, of course, if you don't remove the damage, it triggers weakness."
The researchers believe similar treatments may help in fighting aging sarcopenia.
The study has been published in the December issue of Cell Metabolism, a Cell Press journal.