Is the Position You Sleep in Related to Alzheimer’s Disease?

By Darrell Griffin, president of PureAudacity.com

There are sometimes small things we can do to make big improvements in our health. When we think about Alzheimer’s prevention, we often turn to diet, exercise, and mental stimulation. But an unexpected contender is making headlines in neuroscience circles: sleep position. Could the way you sleep really influence your brain’s ability to fend off Alzheimer’s disease? Researchers say yes, and the numbers are beginning to back them up.

 

Sleep and Brain Health: What the Numbers Show

Alzheimer’s disease currently affects over 6.9 million Americans aged 65 and older, according to the Alzheimer’s Association’s 2024 report. With the population aging, this number is projected to more than double by 2050.

The biological connection lies in the accumulation of beta-amyloid and tau proteins, which form damaging plaques and tangles in the brain. But here’s the hopeful twist: the brain doesn’t just sit idly by. During deep sleep, it activates the glymphatic system, a process that flushes out these harmful proteins.

One groundbreaking 2013 study published in Science found that the glymphatic system is 10 times more active during sleep than when awake. That’s not just fascinating—it’s potentially life-changing.

How Sleep Position Comes Into Play

A 2015 study from Stony Brook University used dynamic contrast-enhanced MRI scans to evaluate how sleep position affects this cleansing system. The researchers discovered that lateral sleeping—sleeping on your side—led to significantly better glymphatic transport in rodents compared to sleeping on the back or stomach.

In fact, the side position increased the brain's ability to clear beta-amyloid by up to 25% compared to the supine position in these models.

Why might this be happening? This could be due to improved cerebrospinal fluid flow or reduced compression of brain tissue and blood vessels in the lateral decubitus position. While we need more human studies, preliminary imaging suggests similar patterns.

The Risk of Back Sleeping and Sleep Apnea

Back-sleeping can also contribute to health issues that increase the risk of Alzheimer’s, especially obstructive sleep apnea (OSA). According to the American Sleep Apnea Association, an estimated 22 million Americans suffer from sleep apnea—often unknowingly.

People with untreated OSA experience frequent awakenings and oxygen drops during the night. This isn't just bad sleep—it's a cognitive threat. A 2019 study published in Sleep journal found that individuals with untreated moderate to severe OSA had a 70% higher risk of developing mild cognitive impairment and dementia compared to those without apnea.

Even more concerning: OSA has been associated with a 43% higher beta-amyloid burden in the brain, as measured by PET imaging studies.

The Bigger Picture: Sleep Duration and Quality

It’s not just about how you sleep, but how long and well you sleep. The CDC recommends 7–9 hours of sleep per night for adults. Yet nearly one-third of U.S. adults report getting insufficient sleep regularly.

In a 2018 study published in JAMA Neurology, individuals who averaged fewer than 6 hours of sleep per night showed a 25% higher beta-amyloid accumulation in the brain than those who slept 7–8 hours.

And even short-term sleep loss adds up. A 2017 study from the National Institutes of Health found that just one night of sleep deprivation led to a 5% increase in beta-amyloid buildup.

Circadian Rhythms, Melatonin, and Brain Protection

Your body’s internal clock—the circadian rhythm—regulates hormone production and cellular repair. Melatonin, released at night, not only promotes sleep but acts as a potent antioxidant.

Disruption of this rhythm, whether through irregular schedules or excessive nighttime screen time, can suppress melatonin and reduce the brain’s defenses. Research published in Frontiers in Aging Neuroscience suggests that low melatonin levels are consistently found in individuals with Alzheimer’s disease.

Practical Tips to Support Brain Health Through Sleep

Here’s how you can support your brain while you sleep—both with position and hygiene:

• Aim for 7–9 hours of high-quality sleep each night.
• Favor sleeping on your side—especially the left. Consider a body pillow for comfort.
• If you snore or wake frequently, consult a sleep specialist to test for sleep apnea.
• Keep a regular sleep schedule, even on weekends.
• Minimize screen exposure 1–2 hours before bed to protect your circadian rhythm.
• Limit alcohol and caffeine, both of which interfere with deep sleep cycles.
• Exercise during the day, which has been shown to improve sleep quality and glymphatic function.

Who Should Be Especially Mindful?

• Older adults (glymphatic efficiency declines with age)
• Those with a family history of Alzheimer’s
• People with sleep apnea or snoring
• Anyone experiencing frequent cognitive “fog” or forgetfulness

A Note on Limitations

While the numbers are compelling, most sleep position studies rely on animal models, small sample sizes, or indirect imaging. Large-scale, longitudinal studies in humans are still needed to confirm causality.

Still, given the low risk and other health benefits of side-sleeping (like reduced acid reflux and improved circulation), there’s little downside to adjusting your sleep posture.

Final Thoughts

The emerging science offers a fascinating perspective: something as routine as your sleep position could impact the health of your brain for decades to come. From reducing your beta-amyloid levels to improving breathing and circulation, the lateral sleep position may provide the brain with a more thorough nightly cleaning.

As researchers continue to explore this link, one thing is clear—sleep isn’t just about rest. It’s about restoration, detoxification, and, possibly, protection against Alzheimer’s disease.

So tonight, as you crawl into bed, give your brain the best chance to reboot—try sleeping on your side.

Disclaimer: The content provided in this article is for informational purposes only and does not constitute medical advice. I am not a doctor, and the information presented should not be used as a substitute for professional medical guidance. Always consult with your healthcare provider before making any decisions regarding your health or sleep habits.