A study in mice has found that cooperation between molecular circadian clocks in the brain and muscle tissue is essential to keep muscles functioning and healthy. Altering feeding times could enhance the internal clock’s function and promote healthier aging in people. Circadian rhythms are controlled by a number of clock genes that can become dysregulated by altering sleep-wake cycles, especially in older individuals. Disruptions to these rhythms can lead to a variety of health consequences, as shown in studies of shift workers.
The study, published in Science, revealed that rather than being controlled entirely by a brain clock, circadian rhythms rely on cooperation between molecular clocks in the brain and muscle tissue to maintain muscle health and function daily. Manipulating these clocks through altering eating times may help protect muscle function in older individuals. By restoring rhythmic gene expression in muscles through time-restricted feeding in old adult mice, researchers were able to prevent the deterioration of muscle function, suggesting a potential way to reinstate the functioning of circadian clocks in the brain and muscles to promote healthier aging.
As people age, changes in the sleep-wake cycle and loss of muscle mass are closely related. Aging is typically accompanied by a shift in sleep to earlier hours, with waking up earlier in the morning and going to bed earlier in the evening. However, older individuals, particularly those with neurodegenerative disorders, may experience disrupted and irregular sleep patterns. Animal studies have shown a reduction in the expression of clock genes in the brain’s suprachiasmatic nucleus as animals age, leading to circadian rhythm disruption. These findings shed light on some of the physiological changes that occur as we age and how time-restricted eating might help correct them, although further research is needed to confirm these effects in humans.
Time-restricted eating, or intermittent fasting, has metabolic benefits such as weight loss and positive effects in nonalcoholic fatty liver disease, cancer, and cardiovascular disease. The study’s findings suggest that aligning food intake with circadian rhythms may help prevent muscle aging in older individuals. While restricting food intake to the active period in old adult mice partially restored central clock function and enhanced the skeletal clock, more research is needed to determine if time-restricted eating could be beneficial for older people in general or for age-related disease. These results provide a starting point for exploring the effects of meal patterning on aging and the potential impact on circadian clock functioning.
Overall, the study highlights the importance of circadian rhythms in maintaining muscle health and function. By cooperating with molecular clocks in the brain and muscle tissue, strategies such as altering feeding times could potentially promote healthier aging in people. Further research is needed to fully understand the underlying biological pathways and implications for human health. While the findings offer valuable insights into the relationship between circadian rhythms, muscle aging, and time-restricted feeding, human trials are necessary to confirm these effects and determine the potential benefits for older individuals and age-related diseases.
