Why Do We Need Sunlight?​

Created By RISC | 6 days ago

Last modified date : 6 days ago

Plants need sunlight for photosynthesis. Without it, they wither and die. ​But we need it too. How? Let's find out.​

We sleep at night and wake up in the morning with help from a hormone called melatonin. Melatonin helps regulate our sleep-wake cycle so we wake up refreshed. But this procedure relies heavily on light, particularly sunlight. The pineal gland in our brain generates more melatonin at night, making us sleepy. Melatonin levels drop when the sun rises and we’re exposed to sunlight, making us feel alert and ready to face the day.​

This "Circadian Rhythm" corresponds to the day-night cycle. Several other hormones contribute. Cortisol levels, for example, rise during the day, keeping us alert. This rhythm regulates serotonin, which controls mood, and even activities such as digestion, so we know when to eat or rest. ​

​So what if we don’t get enough sunlight?​

​The primary result is that the body's processes are disrupted. Without sunlight to regulate our internal clock, melatonin may not be released at night and cortisol may not be activated throughout the day. We may struggle to fall asleep at night and feel tired throughout the daytime. This disruption also has an impact on other processes such as digestion and metabolism, causing us to feel hungry at unusual times, such as late at night, or not at all throughout the day. These imbalances can cause additional health concerns.​

Aside from the physical repercussions, a lack of sunlight can harm our mental health. People who live in places with long winter nights, such as regions of Europe, are more likely to suffer from Seasonal Affective Disorder (SAD). Reduced sunlight exposure throughout the day, along with chilly weather, causes serotonin levels to drop, resulting in sadness or anger. ​

​RISC hopes that this post inspires you to get outside, enjoy a little sunlight, and re-energize yourself for the day ahead.​

​Story by Nattapat Tanjariyaporn, Senior Researcher in Brain Computer Interface, RISC​

​References:​
1. The Impact of Sleep and Circadian Disturbance on Hormones and Metabolism​
2. Circadian Rhythms and Hormonal Homeostasis: Pathophysiological Implications​
3. Circadian rhythm disruption and mental health​
4. The Impact of Sleep and Circadian Disturbance on Hormones and Metabolism​