Image credit: https://www.liveli.com/blogs/the-wave/circadianrhythm
A circadian rhythm or circadian cycle is a natural, internal process that regulates the physical, mental, and behavioral sleep–wake cycle and repeats roughly every 24 hours. These natural processes respond primarily to light and dark and affect most living things, including animals, plants, and microbes.
Circadian rhythms are controlled by a series of “biological clocks”. Biological clocks are organisms’ natural timing devices. They’re composed of specific proteins that interact with cells throughout the body. In vertebrate animals, a “master clock” in the brain coordinates all the other biological clocks, keeping them in sync. In humans, the master clock is a group of about 20,000 nerve cells (neurons) that form a structure called the suprachiasmatic nucleus, or SCN. The SCN is in a part of the brain called the hypothalamus and receives direct input from the eyes. When deprived of light, humans adapt to a cycle that is slightly longer than 24 hours. This is the reason why morning exposure to light is so important. Without regular exposure to light, our master clock can become less in tune to the 24-hour cycle.
Circadian rhythms can influence important functions in our bodies, such as:
- Hormone release
- Eating habits and digestion
- Body temperature
Most people notice the effect of circadian rhythms on their sleep patterns. The SCN controls the production of melatonin. It receives information about incoming light from the optic nerves, which relay information from the eyes to the brain. When there is less light—for example, at night—the SCN tells the brain to make more melatonin so you get drowsy.
Factors that can Change Circadian Rhythms
Changes in our body and environmental factors can cause our circadian rhythms and the natural light-dark cycle to be out of sync. For example:
- Mutations or changes in certain genes can affect our biological clocks.
- Jet lag or shift work causes changes in the light-dark cycle.
- Light from electronic devices at night can confuse our biological clocks.
These changes can cause sleep disorders, and may lead to other chronic health conditions, such as obesity, diabetes, depression, and seasonal affective disorder.
How Daylight Savings Time Affects Sleep
Humans and other mammals are guided by circadian rhythms, which are largely dependent on light exposure. In order to reset each day, they must be synchronized with natural light-darkness cycles in order to ensure healthy, high-quality sleep.
The transition between DST and Standard Time has darker mornings and more evening light. This can essentially “delay” your sleep-wake cycle, making you feel tired in the morning and alert in the evening. Circadian misalignment can contribute to sleep loss, as well as “sleep debt,” which refers to the cumulative effect of not getting enough sleep on a regular basis.
Humans are most vulnerable to sleep deprivation in early March, as they transition from Standard Time to DST. One study found that the average person receives 40 minutes less sleep on the Monday after “Springing Forward” compared to other nights of the year.
Major sleep disruptions are less likely to occur in November when DST ends and Standard Time begins. In fact, gaining an extra hour of sleep often leaves people feeling more refreshed following the end of DST. People may experience some moderate effects such as difficulty adjusting to a new wake-up time.
While many people adapt to time changes, some studies have suggested the human body never fully acclimates to DST. Rather, their circadian misalignment may become a chronic or permanent condition. This can lead to more serious health problems, especially for those who experience “social jet lag” because their demands at work or school take precedence over a full night’s sleep. Social jet lag has been linked to a higher risk of obesity, depression, and cardiovascular disease.
The beginning of DST in March is associated with so many negative outcomes and risk factors that some experts advocate for abandoning the system altogether in favor of a year-round time. They argue a permanent standard time is more in line with human circadian rhythms, and that this schedule would carry benefits for public health and safety. People in favor of DST argue that at least 70 countries around the world observe DST as it decreases energy consumption, reduces costs, and protects the environment. There is also evidence that crime rates decrease with the use of DST due to the decrease in dark hours.
In preparation for the change from Standard Time to Daylight Savings Time, gradually alter your bedtime. Sleep experts recommend waking up 15-20 minutes earlier than usual for two or three days prior to the time change. Then, on the Saturday before the time change, set your alarm clock back by an additional 15-20 minutes. Adjusting your wake-up time can help the body make a smoother transition when the time change occurs.
Practice good sleep hygiene. Sleep hygiene refers to practices that can influence sleep for better or worse. In order to ease the transition of the time change, you should refrain from consuming alcohol before bed. While drinking can cause you to feel sleepy initially, alcohol also causes sleep disruptions and leads to poor sleep quality. Heavy dinners and snacks before bedtime can also negatively affect how well you sleep that night.
Establish a consistent sleep routine. Going to bed and waking up at the same time each day – including the weekends – is a healthy sleep hygiene practice that can also prepare you for time changes. Make sure you get at least seven hours of sleep each night before and after transitioning to or from DST.
Spend time outdoors. Since natural light is a driving force behind our circadian rhythms, exposure to sunlight can alleviate feelings of tiredness during the day that often accompany time changes. Spending time outside during the day also suppresses the production of melatonin.
Nap in moderation. People who experience sleep debt as a result of DST may find some relief by taking short naps during the day. These naps should never exceed 20 minutes in length; otherwise, you may wake up feeling groggy. Rather than adjusting your wake-up time on Sunday morning immediately following a time change, consider a nap that afternoon instead.
At Satori Integrative Medicine, our services include integrative medicine, ketamine and lidocaine infusions, IV supplements, and medical acupuncture. We encourage our patients to incorporate lifestyle practices into daily life as part of a comprehensive treatment plan for: major depression, the depressed phase of bipolar disorder (bipolar depression), postpartum depression, anxiety, post-traumatic stress disorder (PTSD), obsessive compulsive disorder (OCD), pain syndromes such as fibromyalgia and complex regional pain syndrome (CRPS), also known as reflex sympathetic dystrophy (RSD), and addiction.
If you or someone you know suffers from any of these conditions and this approach to health and wellness resonates with you, please contact us for more information.