If you tried to sleep on an empty stomach, you probably know the strong link between your gut and your ability to sleep.
Hunger can keep you awake for a long time until you finally decide to go to the fridge and grab a snack. The same happens if you experience heartburn, which is typically worse when you lay down. Not being able to sleep is a common problem when you have digestive symptoms, but what is the source of this connection?
As you will see next, your gut is associated with your mind in many levels. It is not a coincidence, and has a psychological and biological explanation to it. We typically see examples where gut problems cause sleep issues, but can sleep deprivation trigger or worsen gastrointestinal issues?
Sleep and the gastrointestinal system
Sleep disorders affect millions of people worldwide, and the majority do not reach the recommended 7-9 hours of sleep every night. We can have several health problems if we don’t sleep properly, including hypertension, stroke, diabetes, and heart attack. So, it won’t be surprising to find out that the same happens with the gastrointestinal tract.
Sleep and the gastrointestinal system physiology share a few key elements. There’s a gut-brain axis that connects both organs, sending signals to change intestinal permeability, hormone release, and release of fluids to the gut. This connection goes through the sympathetic and parasympathetic nervous system (also known as autonomic nervous system). There’s also an enteric nervous system that makes things a bit more complicated, but the basic relationship between sleep and the gut comes from the autonomic nervous system.
When we sleep, the autonomic nervous system tells your gastrointestinal tract to behave a bit differently. Your saliva production decreases, the frequency of bowel movements becomes reduced, swallowing rate is also reduced, and so it happens with the acidity of the stomach (pH levels go slightly up).
The connection can be psychological as well, because we know how important is our psychological state to maintain proper bowel function. Again, through the autonomic nervous system, you can experience constipation when you’re stressed, and regain your bowel movements when you feel relax and calmed.
Gastrointestinal diseases and sleep deprivation
The relationship between the gastrointestinal system and sleep is mediated through the gut-brain axis. Then, what happens when we go through sleep deprivation periods?
Here’s a list of health conditions associated with poor sleep:
- Gastroesophageal reflux: It is usually detected by symptoms such as heartburn, a metallic taste in the mouth, nausea, and others. These symptoms are mostly nocturnal because they are triggered by lying down in bed, especially if you don’t have appropriate neck support. A significant proportion of people with GERD also have sleep problems because of heartburn, but the association goes in both directions. Sleep apnea and obesity are common links, causing sleep dysfunction and gastroesophageal reflux at the same time. According to statistics, people with GERD have a higher chance of complications (Barrett’s esophagus) if they also have a poor sleep pattern.
- Peptic ulcers: In this regard, studies are not very conclusive, and there are only a few. But there appears to be a connection between sleep and peptic ulcers. According to one study that evaluated day workers versus shift workers, people who work at night were twice as likely to have peptic ulcers compared to day workers. Work stress and meal timing can be possible causes, but sleep dysfunction is not ruled out as a possibility.
- Irritable Bowel Syndrome: It is often felt as abdominal pain and discomfort, sensitivity to certain foods, early satiety, bloating, and a sensation of heaviness after eating. Similarly, a lot of studies show that people with IBS are more likely to report poor sleep patterns. Researchers say it is likely that poor sleep triggers an activation of the immune system and inflammation in the bowel. This causes more symptoms and a disrupted sleep in a never-ending vicious cycle.
- Colorectal cancer: Sleep is not a direct cause of colorectal cancer. However, there is an 50% increase of colorectal adenoma risk in people who sleep less than 6 hours compared to those who sleep 7 hours or more every night. Sleeping too much and not sleeping enough is associated to obesity, which is also linked to a higher risk of colorectal cancer. Additionally, it is known that for each hour of sleep deprivation, we can have as much as 8% increase of inflammatory mediators in the blood. They cause systemic inflammation and increase the risk of colorectal cancer and other inflammatory diseases.
What can we do?
Sleep deprivation is sometimes a difficult foe to go against. It is never easy to deal with insomnia, and sometimes we feel very tired but can’t get asleep. If this happened to you, thinking about gastrointestinal problems because you’re not sleeping won’t help. It will only make you more anxious, and make you want to sleep harder. And ironically, the harder you try to sleep, the more difficult it gets.
So, instead of forcing yourself to sleep and turning your bed into a focus of anxious thoughts, adopt a few habits that will slowly make you regain your sleep quality:
- Do not stay in bed for hours trying to sleep. After 20 minutes lying down, go to the next room, read a book, listen to some music, meditate. As soon as you feel that itching in your eyes, go back to sleep again.
- Turn off screens at least one or two hours before bedtime. That includes your laptop and mobile device. You can also turn the night filter on, which reduces the blue light reflection and helps you recover your circadian rhythm.
- Wake up at the same hour every day, even weekends. If you can take a walk round the block or do an outdoor activity, it will also help your body adjust your internal clock through sunlight exposure.
- Create a bedtime habit, something you do every night to calm down and relax before sleep.
- Stop using your bed to watch movies or work in your laptop. Save your bed for only two things: sex and sleep.
Khanijow, V., Prakash, P., Emsellem, H. A., Borum, M. L., & Doman, D. B. (2015). Sleep dysfunction and gastrointestinal diseases. Gastroenterology & hepatology, 11(12), 817.
Chakradeo, P. S., Keshavarzian, A., Singh, S., Dera, A. E., Esteban, J. P. G., Lee, A. A., … & Swanson, G. R. (2018). Chronotype, social jet lag, sleep debt and food timing in inflammatory bowel disease. Sleep Medicine, 52, 188-195.
Hyun, M. K., Baek, Y., & Lee, S. (2019). Association between digestive symptoms and sleep disturbance: a cross-sectional community-based study. BMC gastroenterology, 19(1), 34.
Thapa, R., & Subedi, S. (2018). Social Media and Depression. Journal of Psychiatrists’ Association of Nepal, 7(2), 1-4.
Lei, W. Y., Chang, W. C., Wong, M. W., Hung, J. S., Wen, S. H., Yi, C. H., … & Chen, C. L. (2019). Sleep disturbance and its association with gastrointestinal symptoms/diseases and psychological comorbidity. Digestion, 99(3), 205-212.