This Is the #1 Best Sleep Position for Preventing Cognitive Decline, According to Neurologists
As we get older, it can be harder to concentrate, solve problems, focus and perform other cognitive tasks. What a bummer (at best)! If you’ve experienced this, you’re not alone: Cognitive decline affects everyone eventually, to some degree.
You may have already heard about (or even tried) some practices that can prevent cognitive decline. For example, there’s cardiovascular exercise, which is associated with lower odds of dementia. Plus, not smoking and taking B vitamins are other tips to help keep your mind going strong. But did you know that sleep position is another contributing factor?
Yep, according to neurologists and research studies, the way you lie in bed affects more than just your comfort level. Your sleeping position can affect your body’s daily functions, which, in turn, affect brain things, like memory. But which position is the best position—and which is the worst one—for staying mentally sharp as you age?
The Best Sleep Position For Preventing Cognitive Decline, According to Neurologists
Dr. Chris Allen, MD, sleep science advisor at Aeroflow Sleep, board-certified sleep medicine physician and pediatric neurologist, says “Sleeping on your side, particularly the left side, is considered beneficial for several reasons, especially in relation to cognitive health.”
The jury is still out on the exact degree to which this practice is helpful since the research is ongoing, he continues, but studies have shown notable associations.
“While exact human data is pending, animal studies indicate that side sleeping can boost brain waste clearance by up to 25 percent compared to other positions," says Dr. Steve Laureys, MD, PhD, a neurologist, neuroscientist and brain expert at Moonbird. “This improvement suggests that side sleeping may play a crucial role in promoting long-term cognitive health.”
At the same time, remember that research findings can be a “correlation does not mean causation” situation.
“It’s important to note that this is not a direct cause-and-effect relationship, but rather a potential association that needs further research to evaluate this possibility fully,” says Dr. Peter Gliebus, MD, director of cognitive and behavioral neurology at Marcus Neuroscience Institute, a part of Baptist Health South Florida.
But assuming the findings are true, these doctors share a few possible explanations as to why side-sleeping may be key.
Your body can clear toxins more efficiently
Studies show the glymphatic system (aka the brain’s waste clearance system) is responsible for removing beta-amyloid, a protein fragment that's associated with Alzheimer’s disease.
Dr. Gliebus says the clearance process happens primarily at night, and he explains how it happens. “Researchers have found that sleeping position can impact the movement of blood and cerebrospinal fluid through the brain,” Dr. Gliebus says. “They have also discovered that sleeping on the side can improve cerebrospinal fluid clearance.”
These findings are based on animal studies, Dr. Laureys says, but they still "suggest that side sleeping could enhance brain detoxification and reduce the risk of cognitive decline."
It's a possible connection, though, not a fact. “There is no firm data to say whether this association, let alone causation, is actual,” Dr. Gliebus adds.
Side sleeping reduces the likelihood of sleep apnea…
Sleep apnea is basically when someone’s breathing randomly starts and stops. This reduces oxygen supply to the brain, and is therefore linked to cognitive decline, says Dr. Allen.
…and enhances blood flow
Sleeping on your side makes it easier for blood to flow as it should too, Dr. Allen says, which is necessary for brain health and function.
What’s the Worst Sleeping Position for Brain Health?
You can’t always control what position you sleep in because, well, you’re sleeping. But being mindful when you can (and without waking yourself up) may be helpful.
After all, the two other main positions aren’t doing you tons of favors. Dr. Allen says sleeping on the back can increase the risk of obstructive sleep apnea, and that’s no good for your sleep quality or cognitive function.
Additionally, a 2023 study in Sleep Advances found a “relatively strong” association between sleeping on your back and the neurodegeneration found in many cognitive conditions, such as Alzheimer’s, Parkinson’s and other impairments.
Sleeping on your stomach—while perhaps more comfortable, and beneficial if you’re trying to not snore—can cause strain on the neck and spine, he says, and may not be as effective in promoting glymphatic clearance.
“These positions don’t directly cause cognitive decline, but are less efficient in removing brain waste, potentially leading to a greater build-up of harmful substances over time,” Dr. Laureys says.
Your head’s positioning matters too—not only your body’s. He points to a study in the IOS Press Open Library that found head position can significantly impact the brain’s ability to clear neurotoxins, in which side-sleeping is more beneficial for patients with neurodegenerative diseases.
But again, these tips aren’t necessarily foolproof or 100% empirically true—yet. “All of these associations must be tested,” Dr. Gliebus says. “The science on this topic is still very young, so valid conclusions or recommendations cannot be drawn.”
Other Sleeping Tips for Cognitive Health
While the science behind preventing cognitive decline through side-sleeping hasn’t been totally confirmed, doctors do see a strong connection between cognition and sleep generally. “What we do know is that getting enough sleep is crucial for optimal cognitive functioning,” Dr. Gliebus says. “Restorative sleep plays a key role in memory consolidation and managing the metabolic effects involved in ‘brain waste’ management.”
A good night’s sleep also allows for brain restoration and repairs, other forms of cognitive performance, brain development and emotion regulation.
So, how can you make this “good night’s sleep” happen? Ahead, check out the sleep advice provided by these brain and sleep pros.
Maintain a consistent sleep schedule
While it’s no fun to wake up on Saturday morning at the same time as you would for your 9-5, it may be what your body needs—at least most of the time. “Go to bed and wake up at the same time every day to regulate your body’s internal clock,” Dr. Allen encourages.
Not everyone works a 9-5, though, or goes to bed at the same time. Whatever sleep schedule works best for you, stick with it.
Know what to avoid
More specifically, Dr. Laureys encourages skipping out on afternoon or evening caffeine, as well as alcohol, heavy meals and screen time before bed. These things can make it harder to fall asleep and get a restful seven to eight hours.
Prepare your environment for sleep
A quality sleeping space is often cool, dark, comfortable and quiet, Dr. Allen says, encouraging comfortable bedding and blackout curtains.
If you need some sort of noise to help you fall asleep (relatable!), a white noise machine is one of his suggestions. Another option—and quite an unforgettable one, at least for us Swifties—is Mama Kelce’s new gig as a sleep story narrator. Lastly, if you need a mix of noise and cool air to settle down, a portable fan may be the ticket.
Related: Wait, What’s the Difference Between White Noise and Brown Noise? Experts Sound Off
On the note of keeping the room dark, it’s especially important to limit blue light exposure, or the type of light that comes from screens. “Blue light can interfere with the production of melatonin, a hormone that regulates sleep,” Dr. Allen explains.
Engage in mind relaxation techniques
Meditation, deep breathing exercises and reading are all great go-tos, per Dr. Allen’s advice. These activities can calm your mind and make it easier to "turn your brain off." As far as reading, how about one of the 125 best romance books?
Related: Why Alternate Nostril Breathing Should Be Part of Your Nightly Routine
Also, as mentioned earlier, Dr. Laureys works on the Moonbird device team. A Moonbird is a small, handheld breathing assistant that provides breathing exercises to promote relaxation, improve sleep quality and manage stress. It may be what you need to catch some solid Zzzs.
See a professional when necessary
No matter how long you sleep, still wake up feeling unrefreshed? Or maybe you know exactly what the problem is behind your lack of sleep, but don’t know how to address it? Those are some signals that a trip to the doctor’s office might be warranted.
Dr. Laureys says healthcare professionals can treat potential underlying causes, such as psychogenic insomnia, sleep apnea, restless legs and pain. “Studies show that treating these issues can significantly enhance well-being and promote healthy aging,” he says.
At the end of the day—literally and figuratively—remember that quality sleep is important in multiple ways. “Understanding and optimizing sleep hygiene is crucial, not just for preventing cognitive decline, but for overall health and well-being,” Dr. Allen says. “If you have persistent sleep issues or concerns about cognitive health, it’s advisable to consult with a healthcare provider or sleep specialist for personalized recommendations.”
Next up: The Best Side to Sleep on for Heart Health, According to Cardiologists
Sources
Dr. Chris Allen, sleep science advisor at Aeroflow Sleep, board-certified sleep medicine physician and pediatric neurologist
Dr. Steve Laureys, MD, PhD, a neurologist, neuroscientist and brain expert at Moonbird
Dr. Peter Gliebus, MD, director of cognitive and behavioral neurology at Marcus Neuroscience Institute, a part of Baptist Health South Florida
How aging affects focus, Harvard Health Publishing
Cognitive Decline Eventually Affects Everyone, Just Not to the Same Extent, Atrium Health
Could body posture during sleep affect how your brain clears waste?, Science Daily
The Sleeping Brain: Harnessing the Power of the Glymphatic System through Lifestyle Choices, Brain Sciences
The Effect of Body Posture on Brain Glymphatic Transport, The Journal of Neuroscience
P012 Head Position During Sleep: Potential Implications for Patients with Neurodegenerative Disorders, Sleep Advances
Head Position During Sleep: Potential Implications for Patients with Neurodegenerative Disease, IOS Press Open Library
Why at Least 7 Hours of Sleep Is Essential for Brain Health, University of Utah’s School of Medicine
Aging and Sleep, National Council on Aging