उम्र के साथ शरीर की लय भी बदल जाती है : डॉ. पी.डी. गुप्ता
Body Rhythms Shift with Age 

Author : Dr. P. D.GUPTA

(Former Director Grade Scientist, Centre for Cellular and Molecular Biology, Hyderabad, India)


Who wakes us up and who orders us to sleep at the set timings, every day at the same time... how does our biological timekeeping actually work? It turns out that nearly every cell in the human body keeps time by its own means. From the hair cells and skin to the muscles and even kidneys, there are trillions of cellular clocks everywhere in the body.

The relationship between circadian clock, aging, and multiple mental abilities, such as,  learning, thinking, reasoning, remembering, problem solving, decision making, and attention. Aging is associated with a decrease in the activity of the circadian system.  This decrease can contribute to aging and age-related changes in sleep quality, memory, and mood. Neurodegeneration is also associated with aging, affecting sleep quality and circadian clock functions; disruption of sleep and these circadian rhythms will affect cognitive functions.  It is possible that the circadian clock is involved in the control of neurodegeneration.

These tiny clocks, all over the place, keep everything running smoothly in a coordinated way. One can disturb these clocks forcefully and get sick, for example do not sleep during sleeping hours and short or long sleep and face body ache or dull feeling whole day. If we travel from one time zone to another time zone we suffer with jet lag.   

The SCN dictates rhythms in peripheral tissues and physiological activities, such as locomotor activity, sleep-wake cycle, blood pressure, and heart rate. Light, food, and feeding regimens affect either the central clock in the SCN or the peripheral clocks.

It is interesting to note that when these clock reset by themselves due to aging we do not get sick for example Newborns sleep up to 17 hours a day, while teens need more like 10. Teens also tend to stay up later and sleep in longer. As you move into adulthood, you typically settle in to 7 to 9 hours of sleep a night. And after age 65, you might see other shifts, like waking up earlier.  This is because the changes are gradual, with circadian rhythm shifting by approximately half an hour every decade4 beginning in middle age. Research also shows that circadian rhythm timing in older adults is more delicate, leading to fitful sleep if they don't sleep within certain times.

The master clock shots and drives our circadian rhythm in our brain that works 24-hour cycle.  This, addition to sleep-wake cycle, also controls things like body temperature and, hunger. And that clock is wired directly to your eyes, so light has a big effect on it. (The author has his own study and views)