The Impact of Circadian Rhythms on Longevity
Balanced sleep/wake cycle may slow down ageing process
Eberhard Grossgasteiger
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Over the past decade, research has increasingly demonstrated the subtle relationship between circadian rhythms and aging. We now know not only what unbalances rhythms, but also how various lifestyle practices can reset the circadian clock and thus promote health and longevity. But what is a circadian rhythm anyway? And what makes it so meaningful?
What are circadian rhythms?
Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes react primarily to light and darkness and affect most living things, including animals, plants, and microbes. Chronobiology deals with circadian rhythms, which are located in a small region of the brain called the hypothalamus. This evolutionarily preserved mechanism of measuring time enables organisms to synchronize internal processes with time information from the environment and thus ensure optimal adaptation of the organism.
An example of a light-related circadian rhythm is sleeping at night and waking during the day.
Circadian rhythms are primarily controlled from within, but they also react to exposure to light. A structure in the hypothalamus, the so-called suprachiasmatic nucleus (SCN), reacts particularly strongly to light. Almost 80% of SCN neurons show increased activity when exposed to light. Essentially, the light tells our SCN that it is daytime so that the rhythm can be adjusted accordingly.
How do circadian rhythms affect health?
Circadian rhythms can influence important functions in our bodies, such as eating habits and digestion, hormone release, and body temperature.
• Hormones
However, most people notice the effects of circadian rhythms on their sleep patterns. The SCN controls the production of melatonin, a hormone that makes us drowsy. It receives information about incoming light from the optic nerves, which transmit the information from the eyes to the brain. When there is less light — at night, for example — the SCN tells the brain to produce more melatonin to make you drowsy.
Cortisol, on the other hand, increases alertness. In the morning, the hypothalamus activates cortisol production, which gradually decreases throughout the day.
• Screen time
A common trigger for disrupting circadian rhythms is screen time before bed. Blue light in particular causes a very strong response from the SCN, which can persist long after the devices have been removed. This activity impairs melatonin production in the body and can make it difficult to achieve deep sleep.
• Body temperature
The hypothalamus is responsible for maintaining a certain temperature in the body. When it's hot outside, the hypothalamus sends activating signals to the sweat glands to cool the body. On the other hand, when it is cold, it stimulates the muscles and makes them tremble so that the movement keeps the body warm.
Body temperature also fluctuates during our daily cycle. Melatonin actively cools us to promote sleep, which is why our body temperature is lowest at night.
• Metabolism regulation
Metabolism is a chemical process in which food and drinks are converted into energy. The metabolic reactions, particularly those involved in digestion, follow circadian rhythms.
5 - 15% of genes in digestive tissue vary in their expression in accordance with circadian rhythms. Several of these genes are involved in the metabolism of sugar and fats. When looking forward to a meal, the stomach releases the hunger hormone ghrelin, which signals the hypothalamus to stop fat metabolism and stimulate appetite.
How do circadian rhythms affect the aging process?
These rhythms are crucial as they prepare our bodies for food, physical activity and sleep, among other things. When these processes are irregular, the organism is surprised and is sometimes unable to adapt. This can mean that you are constantly hungry or unable to sleep.
Without regular sleep and a healthy diet, sleep quality and digestion suffer. Poor sleep quality and irregular food intake are known to accelerate the aging process and trigger epigenetic changes. (More about epigenetics and aging here.)
While constant circadian rhythms promote health and longevity, disrupted rhythms are associated with age-related diseases such as cancer, cardiovascular disease, and metabolic disorders.
How do circadian rhythms influence biological age?
Circadian rhythms influence our epigenome, and this in turn affects our biological age. When our circadian rhythms become irregular, our lifestyle changes. It is known that irregular sleep and lack of sleep influence our epigenetics and increase our biological age.
How can the circadian rhythm be restored?
Medication, stress, jet lag, irregular sleep patterns, eating or drinking late at night, and other factors can disrupt circadian rhythms. With these tips, you can get your inner clock back under control:
- If possible, maintain a routine every day.
- Stay outside during daylight hours to increase alertness.
- Do enough exercise daily - 20 minutes or more (endurance exercise is generally recommended).
- The sleeping environment should be conducive to recovery, i.e. darkened, cool and noise-free.
- Avoid alcohol, caffeine and nicotine in the evening.
- Switch off screens in good time before going to bed and do activities such as reading or meditating.
- Avoid midday and afternoon sleep.
The circadian rhythm is the body's natural way of keeping its internal 24-hour clock and helps it function according to a balanced sleep/wake cycle. A healthy, active lifestyle that promotes appropriate rest periods helps maintain this important component of our body. Resetting the circadian clock can promote longevity and reduce biological age.
References
- De Nobrega, A.K., Luz, K.V. & Lyons, L.C. (2020). Resetting the Aging Clock: Implications for Managing Age-Related Diseases. Advances in Experimental Medicine and Biology, 193—265. https://doi.org/10.1007/978-3-030-42667-5_9
- Drouyer, E., Rieux, C., Hut, R.A. & Cooper, H.A. (2007). Responses of Suprachiasmatic Nucleus Neurons to Light and Dark Adaptation: Relative Contributions of Melanopsin and Rod Cone Inputs. The Journal of Neuroscience, 27(36), 9623—9631. https://doi.org/10.1523/jneurosci.1391-07.2007
- Van Drunen, R. & Eckel-Mahan, K. (2021). Circadian Rhythms of the Hypothalamus: From Function to Physiology. Clocks & Sleep, 3(1), 189—226. https://doi.org/10.3390/clockssleep3010012
- Tong, J. & D'Alessio, D.A. (2015). Ghrelin and hypothalamic development: too little and too much of a good thing. Journal of Clinical Investigation, 125(2), 490—492. https://doi.org/10.1172/jci79187
- Froy, O. (2011). Circadian Rhythms, Aging, and Life Span in Mammals. Physiology, 26(4), 225—235. https://doi.org/10.1152/physiol.00012.2011
- Acosta-Rodriguez, V.A., Rijo-Ferreira, F., Green, C.A. & Takahashi, J.S. (2021). Importance of circadian timing for aging and longevity. Nature Communications, 12(1). https://doi.org/10.1038/s41467-021-22922-6
Publiziert
2.11.2024
Kategorie
Health
Experte
Over the past decade, research has increasingly demonstrated the subtle relationship between circadian rhythms and aging. We now know not only what unbalances rhythms, but also how various lifestyle practices can reset the circadian clock and thus promote health and longevity. But what is a circadian rhythm anyway? And what makes it so meaningful?
What are circadian rhythms?
Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes react primarily to light and darkness and affect most living things, including animals, plants, and microbes. Chronobiology deals with circadian rhythms, which are located in a small region of the brain called the hypothalamus. This evolutionarily preserved mechanism of measuring time enables organisms to synchronize internal processes with time information from the environment and thus ensure optimal adaptation of the organism.
An example of a light-related circadian rhythm is sleeping at night and waking during the day.
Circadian rhythms are primarily controlled from within, but they also react to exposure to light. A structure in the hypothalamus, the so-called suprachiasmatic nucleus (SCN), reacts particularly strongly to light. Almost 80% of SCN neurons show increased activity when exposed to light. Essentially, the light tells our SCN that it is daytime so that the rhythm can be adjusted accordingly.
How do circadian rhythms affect health?
Circadian rhythms can influence important functions in our bodies, such as eating habits and digestion, hormone release, and body temperature.
• Hormones
However, most people notice the effects of circadian rhythms on their sleep patterns. The SCN controls the production of melatonin, a hormone that makes us drowsy. It receives information about incoming light from the optic nerves, which transmit the information from the eyes to the brain. When there is less light — at night, for example — the SCN tells the brain to produce more melatonin to make you drowsy.
Cortisol, on the other hand, increases alertness. In the morning, the hypothalamus activates cortisol production, which gradually decreases throughout the day.
• Screen time
A common trigger for disrupting circadian rhythms is screen time before bed. Blue light in particular causes a very strong response from the SCN, which can persist long after the devices have been removed. This activity impairs melatonin production in the body and can make it difficult to achieve deep sleep.
• Body temperature
The hypothalamus is responsible for maintaining a certain temperature in the body. When it's hot outside, the hypothalamus sends activating signals to the sweat glands to cool the body. On the other hand, when it is cold, it stimulates the muscles and makes them tremble so that the movement keeps the body warm.
Body temperature also fluctuates during our daily cycle. Melatonin actively cools us to promote sleep, which is why our body temperature is lowest at night.
• Metabolism regulation
Metabolism is a chemical process in which food and drinks are converted into energy. The metabolic reactions, particularly those involved in digestion, follow circadian rhythms.
5 - 15% of genes in digestive tissue vary in their expression in accordance with circadian rhythms. Several of these genes are involved in the metabolism of sugar and fats. When looking forward to a meal, the stomach releases the hunger hormone ghrelin, which signals the hypothalamus to stop fat metabolism and stimulate appetite.
How do circadian rhythms affect the aging process?
These rhythms are crucial as they prepare our bodies for food, physical activity and sleep, among other things. When these processes are irregular, the organism is surprised and is sometimes unable to adapt. This can mean that you are constantly hungry or unable to sleep.
Without regular sleep and a healthy diet, sleep quality and digestion suffer. Poor sleep quality and irregular food intake are known to accelerate the aging process and trigger epigenetic changes. (More about epigenetics and aging here.)
While constant circadian rhythms promote health and longevity, disrupted rhythms are associated with age-related diseases such as cancer, cardiovascular disease, and metabolic disorders.
How do circadian rhythms influence biological age?
Circadian rhythms influence our epigenome, and this in turn affects our biological age. When our circadian rhythms become irregular, our lifestyle changes. It is known that irregular sleep and lack of sleep influence our epigenetics and increase our biological age.
How can the circadian rhythm be restored?
Medication, stress, jet lag, irregular sleep patterns, eating or drinking late at night, and other factors can disrupt circadian rhythms. With these tips, you can get your inner clock back under control:
- If possible, maintain a routine every day.
- Stay outside during daylight hours to increase alertness.
- Do enough exercise daily - 20 minutes or more (endurance exercise is generally recommended).
- The sleeping environment should be conducive to recovery, i.e. darkened, cool and noise-free.
- Avoid alcohol, caffeine and nicotine in the evening.
- Switch off screens in good time before going to bed and do activities such as reading or meditating.
- Avoid midday and afternoon sleep.
The circadian rhythm is the body's natural way of keeping its internal 24-hour clock and helps it function according to a balanced sleep/wake cycle. A healthy, active lifestyle that promotes appropriate rest periods helps maintain this important component of our body. Resetting the circadian clock can promote longevity and reduce biological age.
Experte
Referenzen
- De Nobrega, A.K., Luz, K.V. & Lyons, L.C. (2020). Resetting the Aging Clock: Implications for Managing Age-Related Diseases. Advances in Experimental Medicine and Biology, 193—265. https://doi.org/10.1007/978-3-030-42667-5_9
- Drouyer, E., Rieux, C., Hut, R.A. & Cooper, H.A. (2007). Responses of Suprachiasmatic Nucleus Neurons to Light and Dark Adaptation: Relative Contributions of Melanopsin and Rod Cone Inputs. The Journal of Neuroscience, 27(36), 9623—9631. https://doi.org/10.1523/jneurosci.1391-07.2007
- Van Drunen, R. & Eckel-Mahan, K. (2021). Circadian Rhythms of the Hypothalamus: From Function to Physiology. Clocks & Sleep, 3(1), 189—226. https://doi.org/10.3390/clockssleep3010012
- Tong, J. & D'Alessio, D.A. (2015). Ghrelin and hypothalamic development: too little and too much of a good thing. Journal of Clinical Investigation, 125(2), 490—492. https://doi.org/10.1172/jci79187
- Froy, O. (2011). Circadian Rhythms, Aging, and Life Span in Mammals. Physiology, 26(4), 225—235. https://doi.org/10.1152/physiol.00012.2011
- Acosta-Rodriguez, V.A., Rijo-Ferreira, F., Green, C.A. & Takahashi, J.S. (2021). Importance of circadian timing for aging and longevity. Nature Communications, 12(1). https://doi.org/10.1038/s41467-021-22922-6
Publiziert
2.11.2024
Kategorie
Health
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