Sleep, Circadian Rhythm, and Antiaging Medicine: Circadian Rhythm and Antiaging

The circadian rhythm is a physiological function that maintains the homeostasis of living organisms through adaptation to environmental cycles. The circadian clock, which controls the circadian rhythm, is also commonly referred to as the biological clock and is widely present in vertebrates including humans, as well as in insects, plants, and even photosynthetic bacteria such as cyanobacteria. The origin of the circadian clock is thought to begin with the assimilation of the Earth’s rotation period, i.e., the relationship with the sun, into the basic order of life phenomena within cells. It is a function that was created as one of the adaptation mechanisms to the Earth’s environment. This is an important basic concept when considering the relationship between the circadian rhythm and aging or antiaging. In other words, when there is a mismatch between the day-night cycle of the natural environment and one’s own life rhythm, a failure of the circadian clock inherent in each cell occurs, which disrupts the order of cellular functions, including metabolism. In mammals, the suprachiasmatic nucleus (SCN) in the hypothalamus synchronizes the circadian clocks throughout the body and controls the individual function rhythm as the central circadian rhythm. In recent years, the impact of this circadian rhythm control system on aging and lifespan has been suggested, and attention is being paid to the relationship between the circadian rhythm and antiaging.