Once you disrupt your sleep patterns, for example on vacation, it can be difficult to return to a normal schedule.
This is caused by circadian rhythms.
Let’s find out what they affect and if they can be adjusted.
Circadian rhythms are 24-hour cycles in the human body that run in the background and maintain basic functions.
They are just one of the varieties of biorhythms that accompany living organisms on the planet.
Some of them may be tied to lunar phases, some – to the features of a particular organism.
Their cyclic may be based on seconds or many years.
Among others, one of the most important biorhythms that sustain life is the heart rhythm.
The cycle of sleep and wakefulness is considered the most obvious example of these processes.
But this is not the only cycle to which we are subject.
In fact, almost all the work of the internal organs is subject to certain cycles.
This includes the release of hormones, the change in body temperature during the day, and the acceleration and deceleration of the digestive system.
The existence of fluctuations in nature, which are associated with the change of day and night, were guessed at the time of Alexander the Great.
However, circadian rhythms did not become seriously discussed until the 20th century, when Seymour Benzer and Ronald Konopka discovered that a breakdown in a certain gene in a living organism can disrupt this biological clock.
The gene they found was called the period gene – Per.
Since 1984, scientists Jeffrey Hall, Michael Rosbash and Michael Young have been working on studying the processes by which circadian rhythms function.
As a result, they isolated two more genes, timeless and double time, and several proteins that all together activate the Per gene and allow natural light to trigger necessary cycles in living organisms.
They were awarded the Nobel Prize in 2017 for this discovery.
What circadian rhythms affect
In the morning and afternoon it is easier for us to concentrate, in the evening we are drawn to sleep, we see worse, reactions slow down, it becomes more difficult to digest food.
All this is not a matter of habit, but the work of our circadian rhythms, which affect not only sleep patterns, but also many other processes.
- Sleep and wakefulness
This cycle is influenced by daylight, which signals our brain to produce the hormones necessary for wakefulness.
In the evening, when the sun has already set, our body produces melatonin, a sleep hormone that helps to fall asleep and restore the body during a night’s rest.
- Objectives.
Nutritionists don’t recommend eating in the evening.
Not so much because people move less at night, but because the production of enzymes and substances responsible for feelings of hunger and digestion are also tied to circadian rhythms.
Simply put, during the day, the liver, and pancreas synthesize substances that regulate glucose levels and affect fat and carbohydrate metabolism. - Mental State.
The relationship between circadian rhythms and a stable mental state is based on the production of cortisol, which occurs in the first half of the day.
The most important hormone responsible for resisting stress and cognitive abilities is released in the morning.
Disruption of this process can negatively affect brain function, causing the development of depression, neurodegenerative diseases and dementia.
- The immune system.
Immunity is a complex set of physiological processes that protect the body from foreign elements such as pathogens.
Like many systems, they are subject to circadian rhythms, as immune cells are produced according to these cycles.
This includes the daily synthesis of cytokines, chemokines and cytolytic factors.
An effective immune response depends on the correct functioning of the biological clock.
For example, studies show that circadian rhythms have a positive effect on the effectiveness of anticancer drugs.
- Body temperature.
Thyroid gland and hypothalamus also respond to circadian fluctuations, they insignificantly change the body temperature of a person.
The lowest temperature is recorded at night, between 4 and 6 a.m., and the highest temperature may be recorded in the afternoon, around 6 p.m.
The difference, at first glance, is insignificant 0.5-1 degrees, but necessary for metabolic processes, which are also based on circadian rhythms.
Diagram of circadian rhythm
Diagram of circadian rhythms
What happens in the body in 24 hours and what time it is for:
4:00 p.m. — The time at which, on average, the sun rises and daylight begins.
At this point, the body begins to prepare for awakening.
Sleep becomes shallow.
Cortisol is released. By 6:45, blood pressure rises.
8:00 – It is better to wake up between 7:30 and 8:30 am, this is the time when melatonin secretion stops and intestinal peristalsis increases.
9:00 a.m. — Testosterone production reaches its peak.
10:00 – 18:30 – The time of the highest concentration, the brain perfectly perceives and processes information, reactions are fast, a high tone of cardiovascular muscles.
19:00 – Body temperature increases, blood pressure peaks.
21:00 – Melatonin begins to be produced, the body prepares for sleep.
22:30 – Peristalsis slows down.
2:00 – The Deepest sleep.
4:30 – Body temperature drops.
