Sleep and digestion share a specific requirement: they require your body to relax. Once you relax, your digestive processes kick in to maximize the uptake of essential nutrients in your diet.
Relaxation also ensures you get the sleep you need for optimal deep (slow-wave) sleep. Without this crucial component of sleep, your ability to store memories and think clearly suffers within a few days.
Your sleep position can not only ensure adequate deep sleep, but it can also help your digestion. When your sleep position triggers a relaxed state, you can help your nervous system and its ability to digest food and absorb it while you’re sleeping.
The Science Behind Sleep and Digestion
Your brain and digestive system are highly connected. While the gut has its own “nervous system” called the enteric nervous system (ENS), it is tied to the brain’s central nervous system (CNS) through the autonomic nervous system.
When your brain is relaxed through optimal sleep, you send a signal to your digestive system to optimize peristalsis, take up nutrients, and avoid excessive permeability (leakiness) of the gut membrane.
This connection between your brain and gut is bidirectional because the GI tract can also send back signals to the brain to regulate mood, behavior, and thinking.
The autonomic system (ANS) relays the signal from the cortical brain structures through the brainstem nuclei and to the digestive system. Optimal digestion happens best when the parasympathetic “rest and digest” portion of the ANS dominates over the sympathetic “fight or flight” system. Sleeping properly can ensure that this dominance happens.
Connection Between Sleeping Positions and Digestive Processes
Common digestive issues that may be affected by your sleep position include acid reflux (heartburn), bloating, gas pains, and constipation. There are several reasons why sleep position can impact these digestive issues:
- Sleep position can affect how relaxed you are. If you’re relaxed, your autonomic nervous system can promote improved GI tract function.
- Sleep position can alter your swallowing pattern and salivary tract function, which in turn affects stomach peristalsis.
- Sleeping in certain positions can help gravity, enhancing stomach emptying in those with acid reflux.
Multiple scientific studies have demonstrated the interconnection between sleep positions and gastrointestinal disorders.
- Khanijow, et al. (2015) discussed the interplay between sleep quality and GERD (gastroesophageal reflux disease). Poor sleep equates to reduced salivation and peristalsis, triggering nocturnal reflux (backup of stomach acid). This problem causes heartburn at night, wheezing, and even worsened sleep.
- Schuitenmaker, et al. (2022) used sleeping on the left side to help reduce reflux disease and promote peristalsis for the management of constipation. They noted that side sleeping on the right means that the stomach is above the esophageal opening, promoting acid reflux. By switching to the left side, you may resolve the problem.
- Shepherd, et al. (2013) discussed sleeping on one’s back and its effect on air-swallowing and bloating. Individuals who have sleep apnea or who use CPAP are at risk for worsened bloating when lying supine (on one’s back).
Best Sleeping Positions for Digestion
The three main sleep positions include supine (on one’s back), prone (on one’s belly), and side-sleeping. Sleeping on your side can mean you sleep on your left or right side.
The Left-Side Position
Sleeping on your left side is one of the best sleep positions for heartburn. Your stomach lies on your left side, so when you sleep on the left side, you allow gravity to keep stomach acid in the stomach.
You will also sleep more deeply because of reduced air-swallowing and a lower chance of having sleep apnea. Deeper sleep means better motility of your gut so that digestion is optimized during the night.
Try sleeping on your left side anytime you are constipated or have heartburn. Food and waste will move more easily through your intestinal tract, making the morning bowel movement easier and more spontaneous.
Side-sleeping is used as positional therapy to help those who have a risk of acid reflux during the night. Sleeping on the left is preferred to sleeping on the right side.
The Fetal Position
The fetal position is also excellent for digestion, particularly if you snore.
When in the fetal position, you are less likely to roll onto your back and snore. You can also ease muscle tension in your abdomen and relax into a more dominant parasympathetic nervous system state to allow maximal peristalsis and movement of waste in the gut.
Sleeping Upright
Sleeping upright is not generally comfortable; however, it is excellent for reducing active heartburn symptoms.
Sleeping upright generally means you raise the head of the bed to allow gravity to keep stomach contents in the stomach. You do not need to sleep entirely upright to have reduced heartburn symptoms. You can choose to sleep in a recliner or on a triangular bed pillow that raises your entire torso and not just your head.
Back Sleeping
Back sleeping or sleeping “supine” may help or hurt digestion. If you have back pain interfering with sleep, lying on your back may improve your sleep quality and enhance your parasympathetic nervous system to aid the movement of waste through your intestinal tract.
If you have sleep apnea, however, supine sleeping may worsen digestion. Many with sleep apnea quit breathing more often and swallow more air when sleeping on their back. This can cause bloating and poor digestion both during the night and after awakening.
Tips for Enhancing Digestion Through Sleep
There is clear evidence that sleep position plays a strong role in nocturnal digestion; however, there are other things you can do to ensure optimal digestion at night. These general tips can ensure the best digestion while sleeping (regardless of sleep position).
- Avoid eating before bedtime – Avoid snacking before bedtime and eat your largest meal at noon. Heavy meals before bed only increase the pressure inside your abdomen. This can worsen sleep quality, particularly if it leads to heartburn. Digestion is poorer when you are sitting still after a meal and better with the light activity that can come after a noon meal.
- Avoid high-fiber or high-fat meals before bed – Fat and fiber contribute to a slowing of the stomach emptying time. Instead, eat meals with carbohydrates that are low in fiber or protein-containing foods that do not cause such a slow-down in the transition of stomach contents out of the stomach. Such a change should reduce heartburn.
- Elevate your head – Elevate the head of your bed using an adjustable bed or pillows or by placing a block under the head of your bed. This allows you to sleep in ways that help gravity to keep stomach contents in the stomach while sleeping. Heartburn symptoms are particularly improved when you do this.
- Eat light – If you need to eat before bedtime for other reasons, do not load up on high-volume foods. Eat something that will not add bulk to the inside of your stomach. Eating smaller volumes of food can reduce bloating and heartburn during the night.
- Avoid alcohol – Alcohol lowers the efficiency of the sphincter that keeps food in the stomach rather than in the esophagus. While your perception might be that alcohol helps you sleep, the reality is that you are more likely to awaken during the night with heartburn symptoms.
- Create a comfortable sleep space – Enhance your entire sleep experience by reducing screen time before bed, lowering the lights, and reducing ambient noise at night. Make sure to sleep on a comfortable mattress and in a room that is kept cool so as to optimize your sleep.
Perspectives From the Pros: Professional Views and Expert Standpoints
Jeroen Schuitenmaker, a gastrointestinal medicine researcher, writes about the management of reflux (GERD) using sleep positioning: “Experimental studies have suggested that sleep position plays a role in the occurrence of reflux and the left lateral decubitus position is most favorable. Interventions that aim to promote the left lateral decubitus sleep position might alleviate nocturnal reflux symptoms.”
While the back or supine position is best for back pain, it may not be best for digestive problems made worse by sleep apnea, including bloating and reflux. Mayo Clinic sleep doctor Loise Krahn indicated this about supine sleeping: “Sleeping on the back means that your tongue and jaw can fall down and crowd your airway,”
Personalizing Your Sleeping Position
Finding the right sleep position for your digestive issues may take some time as well as trial and error. Start with your left side because most digestive problems are helped using this sleep position; however, try other positions to find what works best for you. Pay attention to your symptoms and listen to what your body is telling you about your optimal sleep position.
Conclusion
Sleep and digestion happen best when you are relaxed and allow your parasympathetic nervous system to dominate over your stressed-out sympathetic nervous system. Other factors to consider before deciding on an optimal sleep position for your digestive patterns include:
- Which symptoms are affecting you the most (heartburn, acid reflux, bloating, or constipation)?
- Which sleep positions allow you to rest more easily?
- Which sleep positions are best for you and allow you to make use of gravity to optimize your gastrointestinal tract function?
Most people can find a sleep position to help their particular stomach or digestive concern with a little practice.
Be sure to read all you can about sleep positions and digestion, particularly if digestion is an issue for you. The references below provide some good information and are based on recent research on sleep positions and digestion.
There is truly an intricate link between sleep and digestion. By going over the practical advice in this article, you can now make an informed choice about your sleeping position and overall digestive health.
