Here's why our muscles weaken as we age, and how the body fights these effects

The aging process is an ongoing struggle our bodies wage against the ravages of time.

Scientists from the Wellcome Sanger Institute and Sun Yat-sen University have recently made a major breakthrough in understanding this battle by creating the first map of aging human muscle cells. Their study, recently published in Nature Ageing, opens up promising perspectives for the development of therapeutic strategies aimed at promoting healthier aging for future generations.


Veronika Kedlian, a member of the research team, explains that their innovative approach, combining different types of sequencing, has revealed previously unknown cellular mechanisms involved in muscle aging. This breakthrough also provides avenues for future studies.

Using cellular and nuclear sequencing techniques, along with advanced imaging methods, researchers were able to analyze samples of human skeletal muscles. These muscles, which are attached to bones, perform many essential functions such as movement, posture maintenance, body temperature regulation, and nutrient storage. However, with age, these muscles undergo detrimental changes, including sarcopenia, a loss of muscle mass and function associated with aging.

Samples were taken from 17 individuals aged 20 to 75. By comparing the results, researchers identified numerous underlying processes related to age-related muscle changes. Notably, they observed a decrease in the activity of genes controlling ribosomes, the structures responsible for protein production, in the muscle stem cells of older samples. This inactivity reduces the cells' ability to repair and regenerate.

Additionally, researchers noted an increase in the population of non-muscle cells producing a pro-inflammatory molecule called CCL2, thus attracting immune cells to the muscles and exacerbating the muscle degradation process associated with aging.

Conversely, the study also revealed previously unknown compensatory mechanisms. For instance, increased regeneration of certain remaining muscle fiber subtypes was observed, as well as the identification of specialized nuclear populations within the muscle fibers, helping to rebuild declining nerve connections.

Professor Hongbo Zhang, co-lead author of the study, stresses the significance of this research in the context of an aging global population. "Our understanding of the aging process is still limited, but we are beginning to see how muscles strive to maintain their function despite the effects of time," he explains.

Dr. Sarah Teichmann, co-author of the study and co-founder of the Human Cell Atlas, highlights the potential impact of these discoveries. "With this new insight on muscle aging, researchers around the world can now explore ways to combat inflammation, foster muscle regeneration, preserve nerve connectivity, and much more," she states.

This pioneering study offers an unprecedented glimpse into the underlying mechanisms of human muscle aging. Its implications extend far beyond the laboratory, offering new perspectives for the development of therapies aimed at improving muscle health and quality of life as we age.