Maintaining a structured meal schedule, with prolonged fasting periods between meals, regulates the circadian rhythm of muscle cells, according to international research led by the Pompeu Fabra University (UPF) and the Institut de Recerca Biomèdica (IRB) in Barcelona that is presented today in the journal Science. This, in turn, prevents muscle deterioration with age and possibly helps slow the aging of the entire body.
The research is part of a project started eight years ago to understand how the different organs and tissues of the body, which must be active at different times of the day, regulate their circadian rhythms. The ultimate objective of the project is to apply this knowledge to improve people's health.
Previous research had shown that the central clock of the human body is located in the suprachiasmatic nucleus of the brain, which receives information about ambient light directly from the retinas and tells the entire body what time it is at any given moment. IRB and UPF research now shows that organs such as skin and muscles also receive information from the environment that helps them adjust their particular clocks.
In the event that the signal from the brain's central clock deteriorates, as often occurs in older people, peripheral clocks can compensate for this deterioration and restore an appropriate circadian rhythm. In experiments with mice whose central clock is damaged, regulating the times at which they are allowed to eat is enough for muscle cells to recover a correct circadian rhythm.
“The older we get, the more important it is that we take care of the stimuli that set the peripheral clocks,” declares Salvador Aznar-Benitah, Icrea researcher at the IRB and co-director of the project.
In addition to structured meal times, other habits that help maintain healthy circadian rhythms include exposing yourself to sunlight during the day, avoiding short-wavelength lights at night (such as those emitted by many screens), maintaining good sleep hygiene and practicing physical activity, declares Pura Muñoz-Cánoves, who co-directed the research at UPF and currently works at the company Altos Labs in San Diego (USA).
Poor regulation of the body's biological clocks leads to premature aging, researchers have found. In the muscles, the adequate production of proteins is altered, the mitochondria that provide energy to the cells function worse and sarcopenia appears, that is, the deterioration of the muscles that occurs with age and is characterized by a loss of mass. , strength and quality of the fabric. In the body as a whole, mice that have damaged the central clock in the brain die at an age equivalent to 40 years for a person, which is indicative of accelerated aging.
“Cells must oscillate between periods of activity and inactivity. "If we expose ourselves to blue light and eat when it is already night, they interpret that it is still daytime and they function worse," explains Aznar-Benitah, a specialist in chronobiology, who says that "personally I eat every day at the same time, at one o'clock." , and at home we have dinner at eight, no later.”
Although the research has been based on experiments with mice, the results can be extrapolated to people because the mechanisms that regulate the body's biological clocks are the same in both species, the authors of the work point out.
Previous studies have already established that a structured meal schedule is beneficial for health. The IRB and UPF research discovers that it provides this benefit by acting on the peripheral clock of the muscles in a way that compensates for the dysfunctions of the central clock.
As part of the project, the researchers have also studied the relationship between the peripheral clock of the skin and the central clock of the brain. As occurs in muscles, the skin modulates the time signal it receives from the brain from external stimuli. The results of the skin study are published today in Cell Stem Cell, coinciding with those of the muscle in Science.
“We have discovered that the body's clocks work in a federated manner. From now on we can explore how the different organs of the body synchronize with each other”, which can have important implications for taking care of health, highlights Aznar-Benitah.
Using the biological clock study technology they have developed, researchers plan to study whether reestablishing proper circadian rhythms in peripheral organs can slow aging. “It is a question we have asked ourselves since we started this project; Now we have the tools to investigate it,” explains the IRB scientist.
“Muscles represent 50% of the volume and weight of the body, and they secrete a large amount of proteins that have effects on other tissues,” explains Muñoz-Cánoves. “It is possible that if muscle function improves, other organs will also improve.”
