Sunlight and Sleep

- and how they’re interconnected!

Sunlight in the morning is one of the simplest and most effective biohacks. The simple act of waking up and getting sunlight on your eyes and skin has numerous health benefits and can really affect the quality of your life.

I've seen the benefits of sunlight exposure in my life when I started waking up at 6 in the morning and stepped out for a walk. It had a profound effect on the quality of my day. 

How sunlight works!

When you are exposed to sunlight first thing in the morning, a series of processes are initiated throughout your body. It be

gins when photosensitive cells in your eyes are activated with light which then sends signals to the brain.

These signals travel to the suprachiasmatic nucleus (SCN) in the hypothalamus, the region where the brain's master clock for circadian rhythm resides. 

Circadian Rhythm

Circadian rhythm is your body's natural 24-hour clock which orchestrates a symphony of biological processes, affecting your sleep-wake cycle, hormones, digestion, and body temperature. To know more, I highly recommend a book called "The Circadian Code" by Dr. Satchin Panda. 

What happens next is that the production of melatonin is suppressed which is the "sleep hormone" and your body prepares for wakefulness. Production of cortisol, often referred to as the “stress hormone” is stimulated in the adrenal glands, which are located on top of your kidneys and help regulate your energy levels, metabolism, and alertness.

By experiencing sunlight in the morning, you're essentially sending a strong signal to your brain, which then synchronizes various bodily functions including hormone production and optimizing your sleep-wake cycle.

Serotonin - The Feel-Good Hormone

Now comes the fascinating part where exposure to sunlight triggers the production of serotonin. Serotonin is a neurotransmitter and hormone that carries messages between your brain and body. It plays an important role in regulating your mood which is why it’s called the “feel-good hormone”.

Apart from regulating your mood and keeping you focused and emotionally stable, it also plays an important role in digestion, wound healing, bone health, and surprisingly, even sleep. Sleep is where Serotonin really shines. Just 10 to 15 minutes of sunlight boosts not only the serotonin levels but also your Vitamin D levels which is great as many people suffer from Vitamin D deficiency. Regular exercise also helps increase serotonin levels.

The Essential Amino Acid - Tryptophan

But how does the body make serotonin? Serotonin is made from Tryptophan which is an essential amino acid. Essential amino acids are proteins that your body cannot make and therefore must be obtained from the food you eat. Interestingly, 90% of serotonin is produced in the gut and only 10% is made in the brain.

How can you ensure that you are getting enough tryptophan from the foods you eat? Tryptophan is available from in a vast number of foods including meat, poultry, and dairy products. 

From a vegan/vegetarian perspective, nuts such as almonds, cashews, and peanuts, seeds such as pumpkin seeds, sesame seeds, and chia seeds, grains such as oats, quinoa, and buckwheat as well as lentils, legumes, and beans are all good sources of tryptophan. The key here is to obtain this essential amino acid from a variety of sources.

An important point to consider is to consume some carbohydrates such as fruits, vegetables, and whole grains with your protein sources as they help the absorption of tryptophan. A well-planned diet can provide sufficient tryptophan for healthy serotonin production.

Serotonin and Melatonin

I mentioned earlier that in the morning, sunlight suppresses the production of melatonin, the sleep hormone. However, there is a very interesting link between serotonin and melatonin. Serotonin happens to be the precursor or the building block for melatonin.

Enzymes in the body convert tryptophan into serotonin and other enzymes convert some of this serotonin into melatonin in the pineal gland, which is a tiny endocrine gland located deep in the center of your brain.

Now imagine this, as evening falls and daylight fades, serotonin production increases setting the stage for the production of melatonin. As darkness falls, the production of melatonin rises which in turn promotes sleepiness and prepares the body for slumber.

Serotonin and melatonin have a symbiotic relationship and healthy levels of both are essential for regulating your mood and sleep-wake cycle. It was interesting to discover how these hormones and neurotransmitters are connected to each other, and how we can take mindful steps in our daily lives to optimize their functions.

How can you apply this in your life?

When you wake up in the morning, step outside, go for a walk, and get some sunlight, even if it’s for 10-15 minutes. It will have an outsized impact on your mood, metabolism, alertness and will greatly improve the quality of your sleep. Quality sleep is the secret ingredient to a healthy and happy life.