Have you ever felt sleepy mid-day for no reason at all, or experienced extreme jet lag? Our internal, biological clocks regulate our sleep and drive our circadian rhythms. These are consist of typical 24-hour cycles of physical, mental and behavioral changes. Most people are unaware of just how important our master clocks are and how detrimental it can be to our health if not in-check.
What exactly does our circadian rhythms do?
Our circadian rhythms consist of groupings of interacting molecules in cells throughout the body.
“A ‘master clock’ in the brain coordinates all the body clocks so that they are in synch.” (National Institute of General Medical Sciences)
This “master clock consists of a group of nerve cells called the suprachiasmatic nucleus or SCN. The SCN contains about 20,000 nerve cells, located in the hypothalamus which is an area of the brain that is located just above the optic nerves from the eyes cross.
Sleep is regulated by two body systems: sleep/wake homeostasis and the circadian biological clock.
The SCN controls the production of melatonin, the hormone that makes you sleepy. Since it’s located just above the optic nerves, which relay information from the eyes to the brain, it receives information about incoming light.
What can your circadian rhythm affect?
Other important bodily functions
Circadian Rhythms are also known to be associated with…
Seasonal affective disorder
A normal circadian rhythm regulates the genes needed to form the signaling substance VEGF, which is necessary for blood vessel growth- hence the health issues involving weight.
Interestingly, research has also shown that in teens, melatonin levels in blood naturally rise later at night than in most children and adults. Since teens have a tough time going to bed early, it’s important to keep the lights dim as bedtime approaches.
Advancements in research & technology…
Understanding circadian rhythms may help researches to improve treatments for sleep disorders, jet lag, depression and even cancer.
Because some cancer drugs target DNA repair systems, the drugs might be more effective if given earlier in the day, when the body is less active in repairing damaged cancer cells.
The circadian timing system, or CTS, has been shown to be involved in the coordination of almost every physiological and psychological system that has been evaluated thus far. Therefore, it is safe to say that maintaining synchronized circadian rhythms is of vital importance to our health and well-being.
NASA hypothesizes that long-term spaceflights significantly affect the synchronization of the circadian rhythm in humans due to: changes in body composition, reduced physical activity and/or changes of heat transfer, thermoregulation, and non-24-hour light-dark cycle in space. With this knowledge, NASA is now aiming to investigate the changes of core temperature profiles in humans during long-term spaceflight.
“Usually, 36-hour rectal temperature profiles are used to determine any changes associated with the CTS. However, such long-lasting continuous rectal temperature recordings are quite inconvenient for the subjects being investigated, especially during daily exercise and hygiene activities. Therefore, we recently introduced the double sensor, a new non-invasive heatflux method for determining body core temperature. The double sensor is located at the forehead and at the sternum/chest and allows continuous body core temperature measurements for extended periods of time.”
how to get more “in-tune” with your circadian rhythm?
certain changes to one’s sleep schedule can dramatically alter their circadian rhythms. Luckily, research has aided in finding ways to get back in-tune with your master clock.
travelers & jet lag: A short nap at a specific time of day can help you overcome jet lag. This specific time will depend on the time zone you are in.
rotating shift workers: Delay when you go to bed and wake up by one or two hours the last few days of an evening shift. This way, when your night shift begins, you are already almost adapted to your new schedule!
circadian rhythm disorders: bright light therapy may help to shift the circadian system and reset the body’s clock. Properly timed bright light can help advance or delay the sleep cycle.