Through the ages, human beings have been accustomed to waking up and sleeping at a specific time, thanks to the presence of light and darkness, in other words, day and night. Nevertheless, have you ever wondered what happens to your body when your circadian rhythm is influenced by external factors like jetlag, stress, or lack of exposure to sunlight?  Simply put, it takes a toll on your body.

Disrupting your circadian rhythm has serious consequences on the mind and body. That’s why it is important to take care of your body by sleeping and waking up at regular times. Irregular sleep schedules, exposure to sunlight travelling across different time zones, alcohol, and excessive use of caffeine can all affect your body’s internal clock, also known as the circadian rhythm. 

The circadian rhythm is mediated by an area in the brain called the hypothalamus. This section of the brain coordinates the release of hormones like dopamine, which affects body temperature and blood pressure. Dopamine also makes us sleepy in the morning, while cortisol, another hormone, restores our alertness and increases blood pressure.

If your body’s internal clock is mismanaged, you can experience sleeping problems, fatigue, difficulty focusing on tasks, and other health issues like obesity, diabetes, and mood disorders.

Why is the Body’s Internal Clock Important? 

Checking in at a hospital is necessary when you experience a health emergency. Nevertheless, did you know that hospitals are among the worst environments imaginable for maintaining your circadian rhythm? That’s because hospitals have little or no natural light in most rooms. Other factors that can make the situation worse are that patients are constantly interrupted by noise and other procedures that take place at night. 

Research has shown that premature babies who are born in hospitals and get 12 hours of light followed by 12 hours of darkness are usually discharged earlier than those who are exposed to near-constant darkness or light. That’s why, for the circadian rhythm to work effectively, our bodies must be exposed to proper light and darkness.

In order for your metabolism and digestive process to work effectively, your body has to be exposed to proper light. After all, the circadian clock regulates the metabolic process. Metabolism isn’t just about the digestion of food. It is also about how the cells work collaboratively and use energy to perform the tasks that keep us alive and functioning. 

Research suggests that patients with chronic diseases like heart disease and other degenerative diseases that cause mental decline might experience remarkable improvements in their health by changing their behavior to synchronize their internal clock. Doctors agree that our body’s internal clock can work effectively when we figure out the optimal time to eat or exercise, for example. That alone could change our behaviour not only to minimize harm, but also to maximize the health benefits of activities like exercise.

If you want to control and regulate your weight, you must also take note of your body’s internal clock. Aligning your eating habits with your body’s natural circadian rhythm may help with weight loss. Research suggests that having a large breakfast, a medium lunch, and a small dinner can lower your blood sugar level and lead to greater weight loss compared with sizing the meals in reverse order during the day.

It is obvious that the circadian rhythm affects more than just our sleep. It also influences various other bodily functions like hormone release, appetite, body temperature, and even cognitive functions like alertness and attention. 

How Light Affects the Circadian Rhythm 

According to research conducted by Scott Killgore, a professor at the University of Arizona, light plays a crucial role in how our bodies react and behave, thus affecting our circadian rhythm. In the study, Killgore explored light as a treatment for military veterans who have post-traumatic stress disorder (PTSD). His research revealed that exposure to blue light, a proxy for sunlight in the morning, improved his subjects’ sleep patterns remarkably.

Morning blue light, for example, helped people recover from brain injuries and concussions by allowing them to fall asleep an hour earlier, which equates to a better time of night for brain repair. Most of the people in the study had better balance and did better on MRI tests that were conducted because they were exposed to proper light throughout the day. Their visual attention and communication between the neurons in the brain also improved dramatically. 

On the other hand, people who were exposed to light while their bodies were supposed to be resting had an adverse reaction. A study conducted by a neurologist at Northwestern University revealed that one night of moderate light exposure during sleep by leaving the bedroom shades open to streetlights, for example, had a harmful effect on the participants in the study. Not only did it impair the glucose and cardiovascular regulation of the healthy young adults in the study, but it also increased the risk of heart disease and diabetes.

The study conducted revealed that any nighttime exposure to light during sleep led to a substantial and increased risk of obesity, diabetes, and hypertension in adults. The findings in the study support a host of other research initiatives that have shown that exposure to light during sleep can lead to an increased risk of obesity.

According to research by CAREX, 12 per cent of working Canadians, or roughly 1.8 million Canadians, work night shifts. This means that they have to sleep during the day and be active for part of the week. Most likely, they would be exposed to daylight while they should be resting. Working shifts at night and sleeping during the day can adversely affect their health, leading to a wide range of disorders.

In essence, working at night and sleeping during the day goes against the body’s fundamental biology. That’s why researchers and doctors believe that people who work shifts need to eat, exercise, and get the needed light at proper times to offset the health risks they face. 

The Circadian Rhythm and Time

When our circadian rhythm or internal clock is misaligned, it can throw our psychological functions out of order. That’s why when we travel across time zones, for example, we experience chaos as our sleeping and eating habits change. 

If you think about it, time wasn’t invented by humans. Yet, humans invented units like hours, minutes, and seconds to keep track of it. As we go through life, we chart our progress through time using clocks, wristwatches, and calendars; if we give more attention to it, we realize that time significantly impacts our bodies as well!

David Messiha | Staff Writer