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Inconsistent Sleep and Dementia: Understanding Your Sleep Cycle for Better Brain Health

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Cold winter weather and dark mornings may fill you with the desire to put your head back on the pillow, close your eyes and go back to sleep. If you do, it’s understandable, but it’s not a good idea. That’s because irregular sleep patterns disrupt the brain.

According to a new study, going to sleep and waking up at different times each day dramatically increases the risk of dementia.

Today, we'll take a deep dive into how sleep irregularity impacts brain health and what you can do to mitigate your dementia risk-- especially if you have an irregular sleep pattern.

Key Takeaways

  • Inconsistent sleep patterns are linked to a 53 percent increased risk of developing dementia, with irregular sleep contributing to deficits in cognitive functions and impairing the glymphatic system’s efficiency in brain waste clearance.
  • Maintaining a regular sleep-wake schedule and a healthy circadian rhythm is essential for cognitive health, potentially reducing the onset of Alzheimer’s pathology and improving overall well-being.
  • Addressing sleep disorders such as sleep apnea and Restless Legs Syndrome (RLS) is crucial as they are associated with a heightened risk for dementia, and developing consistent sleep hygiene practices and wake times can significantly benefit cognitive function and reduce dementia risk.

The Impact of Inconsistent Sleep on Dementia Risk

Irregular sleep and insufficient sleep is thought to play an essential role in the development of cardiometabolic diseases, a cluster of conditions including heart attack and stroke, high blood pressure, diabetes, and fatty liver disease. Each one of these is a risk factor for dementia.

We’ve previously reported on the work of Professor Matthew Walker, a world-leading neuroscientist and sleep expert who explains that Alzheimer’s is linked to insufficient and low-quality sleep. We've also reported on research that shows how healthy sleep habits can not only save your memory but also help you live longer.

Another emerging aspect of good sleep hygiene is the regularity of the sleep/wake pattern.

The Trouble With Irregular Sleep Patterns

The detrimental impacts of irregular sleep patterns go beyond feeling tired the following day. They can lead to significant deficits in cognitive functions such as attention and working memory. These vital cognitive processes enable us to perform everyday tasks efficiently, from making decisions to processing information.

Consistently going to sleep and waking up at different times may disrupt the circadian rhythm, our internal body clock, and, just as with insufficient or disturbed sleep, this leads to cardiometabolic conditions. Evidence for this comes not only from people engaged in rotating shift work but also from self-reports, sleep diaries, and wearable sleep monitoring devices.

Both acute total sleep deprivation and chronic partial sleep restriction can adversely affect cognitive performance, impacting long-term memory, vigilance, and decision-making abilities. Additionally, sleep deprivation notably obstructs creativity by interfering with the ability to link loosely related ideas, a fundamental component of creative thinking.

Journal Neurology: Recent Study Findings Show 53 Percent Increased Dementia Risk With Inconsistent Sleep

A study in the prestigious medical journal Neurology revealed a startling connection between irregular sleep patterns and dementia risk. Scientists from Monash University in Melbourne, Australia, carried out the study and analyzed data on 88,094 men and women with an average age of 62 who were volunteers in the UK Biobank.

This study used a wrist device to assess sleep regularity over seven days, producing a score from 0 (completely irregular) to 100 (perfect consistency). From this information, the researchers ranked each person’s regularity on a scale – the sleep regularity index (SRI). This calculates the probability of being either asleep or awake at any two time points 24 hours apart, averaged over the seven days. For instance, a person who goes to sleep and wakes up at precisely the same time on each of the seven days would score a maximum of 100 on the index. The score would be zero if it was a different time each day.

Participants were then followed for seven years, during which 480 were diagnosed with dementia.

The results showed that compared to those with an average SRI of 60, the risk of dementia was 53 percent greater for participants in the bottom 20 percent of the index, with an SRI averaging 41. However, those in the top 20 percent, with an SRI averaging 71, did not benefit from a lower risk. Their risk was the same as those averaging 60.

Senior author Matthew Pase explained, “Sleep health recommendations often focus on getting the recommended amount of sleep, which is seven to nine hours a night, but there is less emphasis on maintaining regular sleep schedules.

“Our findings suggest the regularity of a person’s sleep is an important factor when considering a person’s risk of dementia. Effective sleep health education combined with behavioral therapies can improve irregular sleep patterns.

“Based on our findings, people with irregular sleep may only need to improve their sleep regularity to average levels, compared to very high levels, to prevent dementia."

The results underscore the significance of a consistent wake time over the time it takes to fall asleep. These findings suggest that very irregular sleep patterns and disturbances could elevate the risk of neurodegenerative conditions.

Why Sleep Matters: The Importance of Sleep Regularity for Brain Function and Health

Consistent sleep isn’t only about feeling refreshed upon waking; it pertains to overall brain health. A consistent sleep-wake schedule that provides seven to eight hours of sleep per night is critical for maintaining cognitive health and attentiveness.

In fact, when you improve your sleep habits and sleep consistency, research suggests that you can decrease the onset of Alzheimer’s pathology, like tau tangles, in the brain. As we’ll explore in the following subsections, sleep regularity promotes the healthy functioning of the glymphatic system, which clears toxic molecules from the brain, and maintains the circadian rhythm crucial for cognitive function.

Glymphatic System and Cognitive Decline

The glymphatic system plays a significant role in brain health during sleep. It operates predominantly during sleep to eliminate brain proteins and other waste, though its efficiency deteriorates with age.

Irregular sleep patterns and inconsistent sleep may compromise the brain’s housekeeping process, including the clearance of beta-amyloid proteins, potentially leading to memory impairment and a higher risk of Alzheimer’s disease.

This can be a big problem as you age. As you get older, the structure of your sleep changes, and you experience less deep non-rapid eye movement (NREM) sleep, reducing the efficiency of the glymphatic system’s waste clearance.

Circadian Rhythm Disruption

Your body’s internal clock, the circadian rhythm, substantially impacts your cognitive health. The circadian clock governs genetic transcription to prepare the body for expected daily tasks, such as:

  • Improving gene function: Specifically enhancing genes related to synaptic signaling before waking
  • Regulating hormone production throughout the day
  • Influencing sleep-wake cycles
  • Affecting mood and cognitive function

Disruptions to this circadian rhythm can have severe implications for your overall health and your memory. For instance, extended periods of wakefulness disrupt normal processes that contribute to cognitive impairment. For example, shift work can lead to a misalignment of sleep patterns and circadian rhythms, causing metabolic syndrome and cognitive deficits, predisposing individuals to neurodegenerative conditions.

Understanding and maintaining a healthy circadian rhythm and sleep-wake cycle is crucial for overall mental health and well-being.

Strategies for Improving Sleep Regularity

If your inconsistent sleep patterns concern you, don’t lose hope. There are strategies you can adopt to improve your sleep regularity. First, aim for sleeping six to eight hours each night to reduce the risk of developing dementia. You can also utilize consumer technology devices to track your sleep patterns, helping you analyze your sleep regularity and overall sleep health. Avoid excessive daytime napping, which is linked to a higher risk of dementia.

In the upcoming subsections, we’ll detail specific strategies for enhancing sleep consistency, from good sleep hygiene to a steady wake-up time. These non-pharmacological approaches can significantly improve sleep health without the adverse side effects associated with sleeping pills.

Sleep Hygiene

Sleep hygiene involves creating a conducive sleep environment and adopting healthy bedtime habits. Simple things like having an evening cup of chamomile tea, maintaining your bedroom temperature between 60 to 71 degrees Fahrenheit, ensuring proper ventilation and air quality, and reducing clutter can cultivate a conducive sleep environment.

Adopting healthy bedtime habits can also significantly improve sleep quality. The National Sleep Foundation issued a new guideline emphasizing the benefit of consistent sleep schedules. Their multidisciplinary expert panel found that consistent sleep and wake times are important for mental and physical health as well as academic and cognitive performance.

So it’s best to go to bed and get up each morning at the same time, even on weekends. If you have trouble sleeping, the following tips should help:

  • The bedroom should be quiet, dark, and cool at 60 to 71°F.
  • Sleep on a comfortable mattress and use a good-quality pillow.
  • Keep electronic devices out of the bedroom, and don’t use them for at least half an hour before retiring.
  • Avoid big meals, caffeinated drinks, and alcohol in the evening.
  • Get some exercise during the day; tai chi and brisk walking are each proven insomnia fighters.
  • Use white noise machines, soothing music, or pink noise to improve sleep and drown out disruptive noises.
  • Consider aromatherapy with essential oils for relaxation. Studies show that when used at night, it promotes a sharper memory.
  • Try a weighted blanket.
  • Consider sleeping laterally—on your side—which has been shown to help your brain clear away toxins that can kill brain cells.
  • If you have trouble sleeping, consider a natural sleep remedy such as Green Valley Natural's My Sleep Miracle.

These habits can all contribute to achieving normal sleep and ensuring a good night’s rest. If you’re still struggling, talk to your doctor, who may suggest seeing a sleep specialist or visiting a sleep center.

Consistent Wake Time

One of the most effective strategies for improving sleep regularity is maintaining a consistent wake time. Studies have shown that individuals with a consistent wake-up time have better mental health and emotional well-being.

Waking up at the same time every day helps to reinforce the natural sleep-wake cycle, which is beneficial for cognitive function. A consistent wake time aligns with the body’s internal clock, thereby supporting the synchronization of the circadian rhythm, which can help prevent disruptions associated with cognitive decline.

Thumbs-Down to Sleeping Pills if You Want to Avoid Dementia

Sleeping pills are the go-to for millions of people who suffer from poor or restless sleep. We understand the urge but believe there are better choices in many cases. Especially when it comes to the impact of prescription sleeping pills on your brain. The research is clear that prescription sleeping pills dramatically raise your risk of dementia—up to 43 percent in the highest users!

Instead, choose safe, natural sleep aids like Green Valley Natural's My Sleep Miracle. Its efficacy is backed by extensive research, including 22 double-blind, placebo-controlled studies. One key patented ingredient, KSM-66 ashwagandha, resulted in nearly 20 percent longer sleep durations, equating to about an extra hour of sleep each night.

Addressing Sleep Disorders and Their Impact on Dementia Risk

Sleep disorders aren’t simply irritations that interrupt a good night’s sleep; they can drastically heighten your risk of numerous neurological diseases, such as dementia. Patients with sleep disorders like sleep apnea and restless legs syndrome have a heightened risk for multiple neurocognitive disorders, including a whopping 43 percent increased risk for any dementia.

You need to tackle these sleep disorders, not only for sleep quality but also for your cognitive well-being. The research shows that treating primary sleep disorders can slow mental decline and improve symptoms in dementia patients.

In the following subsections, we’ll delve into two common sleep disorders, sleep apnea and restless legs syndrome, their impact on your dementia risk, and what you can do about them.

Sleep Apnea

“Obstructive sleep apnea (OSA) is destroying the health of millions of Americans, and the problem has only gotten worse over the last two decades,” reports Dr. Timothy Morgenthaler, a sleep medicine specialist at the Mayo Clinic. 

For those with the condition, breathing repeatedly stops and starts during sleep and is a leading cause of snoring.

Sleep apnea, a common but frequently disregarded sleep disorder, correlates with a markedly elevated risk of neurodegenerative diseases, especially Alzheimer’s and Parkinson’s disease. A systematic review and meta-analysis have shown hazard ratios indicating higher risks for Alzheimer’s disease and Parkinson’s disease in individuals with sleep apnea.

Interestingly, no significant link has been found between sleep apnea and vascular dementia. This finding suggests that the relationship between sleep disorders and types of dementia is complex and warrants further investigation.

If you consistently have poor sleep due to snoring or other breathing problems, talk to your doctor about the possibility of sleep-disordered breathing or sleep apnea.

Restless Legs Syndrome

Another common sleep disorder, Restless Legs Syndrome (RLS), is linked to an increased risk of all-cause dementia in elderly adults. Alarmingly, the risk of developing vascular dementia associated with RLS is higher than that for Alzheimer’s disease.

While the connection between Restless Legs Syndrome and dementia is clear, the impact of RLS treatment on dementia outcomes is less definitive. Dopamine agonists used for RLS treatment did not exhibit an association with a change in risk for subsequent dementia, suggesting the need for additional research into how medication influences dementia outcomes in RLS patients.

Again, if Restless Legs Syndrome keeps you or a loved one from sleeping well, talk to your doctor. Several treatments are available.

Current and Future Research on Sleep and Dementia

The connection between sleep and dementia, including Alzheimer’s disease, is an emerging research area. Future studies aim to unravel the direct effects of sleep disturbances on Alzheimer’s disease (AD) pathology, and randomized clinical trials are planned to assess the impact of commonly used drugs for clinical sleep problems on long-term cognitive and pathological outcomes.

In the subsequent subsections, we’ll examine the advancements in sleep research and propose potential directions for future studies. These areas of focus will enhance our understanding of sleep and dementia, driving forward our efforts to mitigate dementia risk and improve cognitive health.

Sleep Research Progress

Over the years, sleep research has made considerable progress. Studies have shown that maintaining regular sleep patterns with consistent bedtimes and wake-up times is positively associated with health outcomes in adults, including:

  • Improved cognitive functions
  • Enhanced memory
  • Increased productivity
  • Reduced risk of chronic diseases

These findings highlight the importance of establishing a consistent sleep routine for optimal health and well-being, ensuring the same sleep state and adequate sleep duration each night.

Research tools like the sleep regularity index (SRI) have been developed to measure the probability of being asleep or awake at the same time each day, aiding in the assessment of sleep pattern consistency. These advancements in research techniques and tools have enriched our understanding of sleep and its relationship with cognitive health.

Future Research Directions

Numerous promising avenues exist for future research into sleep and dementia. One key area is the role of sleep apnea in the development of specific dementia biomarkers, which could enhance our understanding of the pathological link between sleep apnea and different types of dementia.

Future research also needs to focus on:

  • Interventions that delay or slow cognitive decline
  • Multimodal approaches that target multiple risk factors to enhance cognitive outcomes
  • Identifying optimal forms of interventions, their doses, delivery schedules, and potential synergies when combined with other interventions

This is a critical area for future research to maximize cognitive outcomes.

Summary

In conclusion, sleep habits play a pivotal role in cognitive health and dementia risk. Irregular sleep patterns and sleep disorders like sleep apnea and Restless Legs Syndrome can significantly increase the risk of developing dementia. On the other hand, maintaining sleep regularity and addressing sleep disorders can mitigate the risk of dementia and slow cognitive decline.

We need to prioritize sleep health, not just for rest and rejuvenation but also for long-term cognitive health. As we’ve seen, a good night’s sleep is more than just a luxury; it’s a crucial component of brain health. So, let’s make every night’s sleep count for your memory and brain health!

Frequently Asked Questions

What is the number one trigger for dementia behavior?

Once a person has been diagnosed with any form of dementia, they'll have good days and bad days. On those bad days, when dementia appears to worsen, research has revealed specific triggers that are at play. The number one trigger for worsening dementia is an overwhelming environment with too much noise or overcrowding, being surrounded by unfamiliar faces, such as having too many caregivers at once. These situations can cause distress and behavioral disturbances in dementia patients, so it's essential to keep this in mind and provide structured and unstructured activities to enhance their quality of life.

What are signs that dementia is getting worse?

Signs that dementia is getting worse include worsening physical state, such as weight loss, loss of mobility, incontinence, and skin infections. These indicate that the body is struggling to function properly.

What are the three stages of vascular dementia?

Vascular dementia typically progresses in three stages: early, middle, and late. These stages can also be categorized as mild, moderate, and severe, based on the impact of symptoms on a person.

What is the middle stage of dementia?

During the middle stage of dementia, the symptoms become more pronounced, including confusion, frustration, and unexpected behavior like refusing to bathe. People in this stage may still be somewhat aware of their condition and need help with daily tasks.

Can irregular sleep patterns increase dementia risk?

Yes, irregular sleep patterns are linked to an increased risk of developing dementia, with participants showing an incredible 53 percent higher likelihood of developing dementia, according to recent studies.


  • VERY IRREGULAR SLEEP LINKED TO HIGHER RISK OF DEMENTIA American Academy of Neurology 12/13/2023
  • Yiallourou SR et al Association of the Sleep Regularity Index With Incident Dementia and Brain Volume Neurology 2024 Jan 23;102(2):e208029 - https://pubmed.ncbi.nlm.nih.gov/38165323/
  • Shenker JI, Singh G. Sleep and Dementia. Mo Med. 2017 Jul-Aug;114(4):311-315. PMID: 30228618; PMCID: PMC6140093. - https://pubmed.ncbi.nlm.nih.gov/30228618/
  • López-García A, López-Fernández RM, Martínez-González-Moro I. Analysis of Sleep Quality in People With Dementia: A Preliminary Study. Gerontology and Geriatric Medicine. 2023;9. - https://pubmed.ncbi.nlm.nih.gov/36726411/
  • Sindi S, Kåreholt I, Johansson L, Skoog J, Sjöberg L, Wang HX, Johansson B, Fratiglioni L, Soininen H, Solomon A, Skoog I, Kivipelto M. Sleep disturbances and dementia risk: A multicenter study. Alzheimers Dement. 2018 Oct;14(10):1235-1242. doi: 10.1016/j.jalz.2018.05.012. Epub 2018 Jul 17. PMID: 30030112. - https://pubmed.ncbi.nlm.nih.gov/30030112/
  • Wong ATY, Reeves GK, Floud S. Total sleep duration and daytime napping in relation to dementia detection risk: Results from the Million Women Study. Alzheimers Dement. 2023 Nov;19(11):4978-4986. doi: 10.1002/alz.13009. Epub 2023 Apr 21. PMID: 37083147. - https://pubmed.ncbi.nlm.nih.gov/37083147/
  • Yiallourou SR, Cribb L, Cavuoto MG, Rowsthorn E, Nicolazzo J, Gibson M, Baril AA, Pase MP. Association of the Sleep Regularity Index With Incident Dementia and Brain Volume. Neurology. 2024 Jan 23;102(2):e208029. doi: 10.1212/WNL.0000000000208029. Epub 2023 Dec 13. PMID: 38165323. - https://pubmed.ncbi.nlm

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