Updated: Sep 6
Ever heard the saying “I’ll sleep when I’m dead”? Whoever said that was literally making a fatal error. Sleep is so important for your health, including your longevity. Sleep helps you to perform important metabolic processes like cleaning up toxic proteins in the brain, REM sleep, where your brain is busy consolidating short-term memories into long-term memories, and even digestion.
Lack of sleep has been associated with many health issues, including increased inflammation, impaired focus, difficulty losing weight, lowered testosterone production, and GI symptoms such as bloating, constipation, and diarrhea.
Getting enough good quality sleep is essential for your well-being and can help you to perform better, reduce risk of disease and make life more enjoyable! This blog will review some of the things that can disrupt your sleep and can help your sleep, as well as discuss the relationship between poor sleep and your gut symptoms.
What can disrupt your sleep
Light helps regulate the human biological clock - The Circadian Rhythm.
The Circadian Rhythm is an internal clock which is set on a 24 hour cycle, that regulates biological processes in all animals, plants, fungi, and even some bacteria. It tells us when it’s daytime, nighttime, when we should have energy, when we should feel sleepy and when it’s food time, and time for activity.
You can finely tune your own circadian rhythm so that you have a healthy, predictable and dependable routine.
While sunlight helps to stimulate the rise of cortisol, we can keep cortisol levels unnaturally high through uncontrolled stress, exposure to sun-mimicking light from computers, phone and TV screens and caffeine. When cortisol levels are elevated into the night this prevents melatonin levels from rising, which prevents us from naturally becoming ready for rest. This pattern continues into the morning when we find it more difficult to wake as melatonin is still in our system. The lack of sleep, chronically elevated cortisol levels and exhaustion can lead to poor digestion, weight gain, difficulty losing weight, stress and illness.
So if you have to use electronics before bedtime, consider installing a program that gradually reduces blue light from the screen after sunset. Fortunately, more and more devices come with such a program preinstalled (e.g.,Night Shift on iPhones and Macs). F.lux is a free app that can be installed on laptops and computers. Also consider the lighting in your house after dark. Do you often have all the lights on? What tone light bulbs do you use? Consider switching for dimmable or yellow tone bulbs, and using side lamps instead of bright overhead lights.
But what if you can’t easily adjust the color balance of your screen? Or if the blue-light source is a lighting fixture in a room you share with other people? In such instances, consider wearing blue-light-blocking glasses a couple of hours before bedtime. Remember, however, that though blue light is the main offender, you should avoid any bright lights in the hours leading to sleep.
Finally, light doesn’t just impact your ability to fall asleep, it can also impact your quality of sleep. If you live in an area where light pollution is a concern, consider installing blackout curtains or using a sleep mask.
I want to preface this section by letting you know that I’m not telling you that you need to give up beloved caffeine in order to get a good night's sleep. Caffeine has it’s benefits and can be consumed on a regular basis without disrupting sleep, as long as you allow enough time for its effects to wear off before bedtime.
Speaking of caffeine's effects - Caffeine can block different adenosine receptors in the brain, with varying effects. By blocking the A1 receptor, which promotes sleepiness when activated, caffeine can increase alertness. By blocking the A2A receptor, caffeine can increase dopamine levels, with stimulating and mood-enhancing effects.
The A1 receptor doesn’t seem to get desensitised, which may be why caffeine doesn’t lose its awakening effect. The A2A receptor does get desensitised, however, which is why regular coffee drinkers often don’t feel true stimulation even after drinking several cups. Because they no longer feel stimulated, it is often assumed that caffeine won’t affect sleep. Even if you find it easy to fall asleep after many cups of coffee throughout the day, caffeine can still make you more alert and your sleep more shallow. For that reason, caffeine should be avoided within the six hours before bedtime.
Similar to light, noise can impair the quality of your sleep. Not all sounds will have the same impact, and everyone has different sensitivity levels to sounds and how much they will impact their sleep.
If you find you’re a light sleeper, and find yourself often waking up to noise, or you notice that noise makes it more difficult for you to fall asleep (maybe your partner snoring or a busy road outside your window), and you’re not a parent, consider using earplugs.
Although alcohol can make you fall asleep faster, because it is a depressant of the central nervous system, research shows that it doesn't improve the quality of sleep, and in fact can have a negative impact.
Alcohol causes relaxation by binding to GABA receptors in the brain, which can help you to unwind, but this effect fades off after a few days if you keep drinking close to bedtime, and right from the beginning it will impair the quality of your sleep.
What can improve your sleep
A consistent sleep routine
Inconsistent sleep routines can disrupt your body clock (circadian rhythm). As mentioned previously, your circadian rhythm follows a 24-hour schedule, influenced by factors such as temperature and light. It can be easily thrown off if you’re following an inconsistent sleeping schedule, which can impact the quality of your sleep and ability to fall asleep. Going to be around the same time every night and waking up around the same time in the morning can help to keep your body clock in check and improve your sleep.
To take things a step further, following a bedtime routine can help to signal to your body that it’s going to be time to lie down and sleep soon. This routine can be as simple as showering then brushing your teeth. Adding in other activities that can help you relax like mediating or spending time reading can be beneficial. Try to avoid any activities that stimulate your senses like playing games or watching horror movies. Don’t forget that light plays a role, so make sure your devices have apps installed that will automatically block blue light once the sun goes down, and to turn off any bright overhead lights in your house.
Magnesium plays an important role in the brain and calming the nervous system, and a lack of magnesium can result in abnormal neuronal excitations leading to impaired sleep. Supplementing magnesium can help to promote a more restful sleep, especially in those prone to magnesium deficiency such as the elderly, people impacted by chronic stress or anxiety, and those who tend to sweat a lot through intense exercise or hot climates.
Just keep in mind when supplementing magnesium that certain times can cause diarrhea in some people. This can be helpful for those who suffer with constipation, but not so helpful if you have normal bowel movements, or already have diarrhea.
Magnesium L-threonate and magnesium glycinate are best for avoiding intestinal discomfort. If you suffer from constipation, you might want to try magnesium citrate, which can help to promote bowel motions but is also well absorbed and can help improve sleep quality.
Regular exercise is associated with better sleep quality, mood, bowel motility and overall health. It is important to point out that when it comes to exercise, more intense forms and over exercising can be detrimental, especially if you have IBS type symptoms.
However, many types of exercise, such as yoga, aerobic exercise, and resistance training have the potential to improve sleep quality, as well as mood and overall health, and regular exercise is consistently associated with better quality sleep.
When the sun sets at night, this signals your body to produce melatonin, which in turn signals your body that it’s time to sleep. This is why it’s important to avoid blue lights (which mimic sunlight) two hours before bedtime. If you do this and still have trouble falling asleep, you may benefit from taking a melatonin supplement.
Relationship between poor sleep and GI distress
Sleep isn’t only important for better performance, mental clarity, metabolism and longevity. For those who suffer with gut issues, your sleeping habits could even be contributing to your symptoms.
One way this dysfunction can occur is via the circadian rhythm. Most people with healthy circadian rhythms and digestive systems will poo at the same time everyday, like clockwork, and this is because the circadian system not only controls when you feel awake and when you feel sleepy, but more recently it was discovered that cells in the intestine also undergo circadian rhythms, influencing gastrointestinal digestion, absorption, motility, hormones, barrier function and the gut microbiota. Disturbance of the circadian rhythm caused by abnormal sleep/wake cycles renders intestinal cells more vulnerable to injury.
So as you can imagine, if your circadian rhythm is dysfunctional and impacting your ability to get enough deep and restful sleep, it could also be impacting your body’s ability to digest, absorb and have regular bowel movements.
The circadian rhythms in the gut are not limited to intestinal cells. The gut microbes also play a key role in the regulation of circadian rhythms. The collection of microbes that resides in your gut undergoes its own circadian rhythms every 24 hours. These circadian rhythms involve changes in the location of gut microbes within the intestine, fluctuations in their adherence to the intestinal wall, and variations in their production of metabolites such as short-chain fatty acids, which modulate gene expression and biochemical pathways both locally in the gut and systemically throughout the body. Through these cyclical mechanisms, the circadian rhythms of gut microbes ultimately affect our own circadian rhythms, which regulate our sleep/wake cycles, hormone release, and metabolism. In addition, our circadian rhythms provide feedback to our gut microbes.
While light exposure and temperature are the primary cues that affect the body clock, intestinal and gut microbe circadian rhythms are primarily influenced by the timing of food intake and composition of the diet. Diet-induced dysbiosis and erratic meal consumption disturb both intestinal cell and gut microbe circadian rhythms and have systemic effects on the body.
Eating a high-fat, high-carb diet loaded with polyunsaturated fats and processed sugars (Standard American Diet) can lead to significant disruption to intestinal and gut microbe circadian rhythms. Erratic eating patterns, such as skipping meals, can also disrupt intestinal cell and gut microbe circadian rhythms. Time-restricted feeding, a practice in which eating is only allowed during a certain window of time each day, has been found to normalise gut microbe rhythms and reverse some of the negative effects associated with circadian disruption.
Finally, lack of sleep can influence digestion and GI related symptoms simply because it’s a stressor to your body. Ever had a bad sleep and woken up the next morning feeling hungover, even though you didn’t touch any alcohol? Trying to stay awake and get on with your usual daily duties is perceived as a stress by your body, triggering the ‘fight or flight’ nervous system. This means that digestion is no longer a priority, and usual digestive processes are disrupted, which can result in symptoms like nausea, reflux, abnormal motility and bloating.
In summary, the importance of good quality sleep goes far beyond better daily performance.
To optimise your sleep, avoid the factors that can impair it, exercise regularly, go to bed at the same time every day, and make sure your diet contains enough magnesium, or consider supplementing. If you suffer from GI issues and also struggle to get a good nights sleep, consider reducing processed foods in your diet and focusing on whole foods, and try to eat at similar times each day and avoid grazing.