Your muscles aid in the most basic of activities, such as walking.

Healthy muscles enable you to move throughout life and support the rest of your body. Without functioning muscles, your body would have trouble stabilizing itself and would be more prone to slipping and falling.

Muscles also help to keep your joints in good shape, allowing you to enjoy playing sports, dancing, walking your dog, and the everyday tasks of making the bed, cooking, and carrying groceries. Whatever we do, physical strength plays a vital role in our daily life. By understanding why our muscles age over time, we can find solutions for slowing our biological aging.

The involuntary loss of muscle strength, mass, and function as we age is termed sarcopenia. Its cause has not yet been understood by modern medicine as it is a multifactorial problem. Scientists are still researching it, but several mechanisms have been proposed, which include a reduction in endocrine function, inactivity, and inadequate nutrition.

In aging, there is an overload of proteins including serine palmitoyltransferase (SPT), a key player in the regulation of transcription, which is the process of copying a segment of DNA into RNA. SPT is needed to convert fatty acids and amino acids into ceramides. This means that as we age, proteins involved in the production of ceramides such as SPT increase. Ceramides, commonly used in skin care products, are sphingolipids, a class of fat molecules that are used to perform various tasks in the cell other than producing energy. Ceramides are the basic structural units of all sphingolipids, which are formed through the union of long-chain fatty acids with sphingosine. Sphingolipids participate in tissue development, cell recognition, and adhesion, act as receptors for toxins, and much more.

A team of scientists at the Swiss Federal Institute of Technology in Lausanne recently conducted research on mice. The purpose of this research was to identify the cause of aging muscle. Mice age similarly to humans, becoming inactive and losing muscle mass and strength. It was discovered that as mice aged, their muscles became packed with ceramides. According to Dr. Pirkka-Pekka Laurila, the lead author of this study in Lausanne, sphingolipids and ceramides are complex and interesting classes of fat that can perform diverse functions. The author also pointed out that there is a high potential to further study ceramides’ role in aging, suggesting that ceramide and sphingolipids have a greater impact on muscle decline than we currently know.

To observe the effect of increased ceramides in our muscles, Laurila’s team experimented to see whether reducing ceramide overload would prevent muscle-function decline. Old mice were treated with ceramide blockers such as myriocin and Takeda-2, and adeno-associated viruses were used to block the production of ceramides in muscle. The ceramide blockers resulted in the prevention of muscle-mass loss during aging, increased the mice’s strength, made them able to run a longer distance, and improved their coordination.

To go deeper, scientists set out to measure every known gene product in the muscle using RNA sequencing. “It turned out that blockade of ceramide production activates muscle stem cells, making muscles build up more protein and shifting fiber type towards fast-twitch glycolytic to produce larger and stronger muscles in aged mice,” said Dr. Martin Wohlwend, the study’s main collaborator.

After conducting the mice experiment, scientists wanted to see whether or not ceramides in muscle could also be beneficial in humans. Thousands of older men and women between the ages of 70 and 80 from Helsinki were examined. Twenty-five percent of them were discovered to possess a particular form of a gene that reduces the gene products of the sphingolipid production pathway in muscles, meaning that those who have this gene can naturally block the production of ceramide in muscles. Those who had the ceramide-reducing gene form walked longer, were stronger, and were better able to stand up from sitting.

These findings indicated those with the ceramide-reducing gene aged better, similar to how the mice treated with ceramide blockers aged.

Much more needs to be studied regarding the impact ceramides have on the aging of muscle, but given the results of this study, ceramide inhibitor supplements may be a good way to maintain optimal muscle strength as we age.