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How a lack of light impacts our brain

In winter, we are often lacking light exposure, especially in the Northern hemisphere. This lack of light can put us in a gloomy, even depressed mood, but what you might not know is that it will actually impact our melatonin production and hence our sleep quality and brain inflammation levels ….

Well and then you know right? Once we have brain inflammation that can impact our appetite for junk food, our ability to focus and concentrate, our hormone production and cause headaches and migraines.

But why is melatonin so important for migraineurs?

“many diseases have been found to associate with melatonin, including migraines. Therefore, melatonin's therapeutic potential for migraine is drawing attention.” Source

Melatonin is a hormone made in the body. It regulates your sleep-wake cycles. It’s what makes us fall asleep and can also have an impact on sleeping through the night as it will help keep our cortisol levels low throughout the night.

But melatonin is also getting more and more attention for its anti-inflammatory properties, especially supporting our brain to detox during the night. Yes that’s right: when we are in deep sleep, our brain is cleaning out the waste (that’s also why we need to have enough of that deep sleep!)

If the brain can’t detox, well the accumulated toxins will stay inside and cause inflammation. This can put you at risk for diseases like Alzheimer’s but also cause brain fog, memory issues, increase your chances of migraine attacks & will cause hormone problems.

It detoxes through your GLYMPHATIC system specific to the brain. This was actually just recently discovered, that our body not only has a lymphatic system to detox but that our brain uses a similar pathway which is now called the glymphatic system. When activated, it drains the brain's junk down into the lymph system of your neck to be carried away.

But let’s go back to why our melatonin production is compromised if we’re not getting enough light exposure in the morning…

As I said above, melatonin is regulating your body’s circadian rhythm or (wake & sleep cycle):

Your circadian clock causes highs and lows of sleepiness and wakefulness throughout the day. Typically, most people feel the sleepiest between 2 and 4 AM (that’s also when we’re usually in our deep sleep phase), and also between 1 and 3 PM (also known as the afternoon slump). Getting enough sleep each night will have a balancing effect on your afternoon slump, but it will also have a positive effect on your blood sugar balance and (non) appetite for junk food during the day.

There’s an area in our brain or hypothalamus (remember I like to call this our computer centre that’s directing all hormone production with our body systems (pancreas, thyroid, adrenal glands, ovaries/testes…), the SCN (suprachiasmatic nucleus) that reacts to signals of dark and light. The optic nerve in your eyes senses the morning light. Then the SCN triggers the release of cortisol and other hormones to help you wake up. Then, when it gets dark at night (well right now in Belgium, there’s no real difference between 9AM or 5PM *sigh*) the SCN sends messages to the pineal gland (another gland located in the brain but outside of the hypothalamus). This gland triggers the release of melatonin at night to help us sleep.

So this is how it should be ideally:

  • In the morning, your cortisol will rise (and be at its highest) to wake you up and give you that energetic “ready to start your day” kind of feeling

  • 20-30 minutes after waking, you’ll be exposed to 30 minutes of bright sunlight to reset your circadian clock and stimulate melatonin production for the night - you see the importance of sufficient light in the morning for sleep?

  • Your cortisol levels will naturally ebb off during the day or towards the end of the day, making you more tired and naturally preparing for sleep

  • Your pineal gland will secrete melatonin at night to make you sleepy so you can go to bed without trouble falling asleep

What DISTURBS your circadian clock:

  • Coffee in the morning is usually fine for most people, but it can of course be a migraine trigger for some. I recommend drinking your coffee AFTER breakfast so it will not impact your blood sugar levels. Consider that caffeine has a 6 hour lifetime, so if you drink it in the afternoon, your cortisol levels will be perturbed and stay higher than they should be. You should also know that caffeine will block the production of Adenosine in our brain, which acts as an inhibitory neurotransmitter. Adenosine will help us sleep.

  • Don’t eat when you’re supposed to sleep and have your meals at the same time

  • Melatonin levels rise about 2 hours before your usual bedtime. In order not to neutralize your melatonin secretion, avoid bright lights and screen lights when it’s dark outside: use screen dimmers or night mode and blue blocking glasses in the evening to avoid stimulation of your brain

Disrupting our circadian rhythm can have a profound effect on your wellbeing: eating late, not getting enough light in the morning or during the day, keeping your brain in hyperactive mode by working on your computer or looking at your phone screen at night, watching TV without blue light protection can all impact your sleep quality, inflammation levels in your brain, blood sugar balance and mood.

So what can you do if you are not able to live in a sunny state during winter?

  • Get a light therapy lamp (I got mine years ago from amazon: Beurer TL40 10.000lux) and use it in the morning to prepare your melatonin production for the night

  • Use blue blocking glasses (can be found widely on the Internet, the main brand being true dark) and wear them once it’s dark outside and you're exposed to screen lights

  • Avoid working after 8PM and put away your phone, tablet etc at least 1 hour before going to bed

  • Make sure your bed room is completely dark

  • Take supplemental melatonin 30 minutes before bed (best is to get your melatonin levels tested before and work with a practitioner to determine dose and duration of taking this)*

*Do not use melatonin if you are pregnant or breastfeeding or have an autoimmune disorder, a seizure disorder or depression. Talk to your health care provider if you have diabetes or high blood pressure or take hypertension medications.


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