Poor Sleep and Alzheimer’s Disease
I’m sure you’ve experienced periods of poor sleep in your life, perhaps as a new parent or during a time of high stress. Even a single night of sleep deprivation affects hormones and metabolism the next day. You might notice that when you are tired, you feel hungrier and rely more on sugar and caffeine to get you through the day. Or that you feel more brain fog, forgetfulness and other brain symptoms.
The body needs sleep for rebuilding, repair, detoxification and a host of other physiologic processes. We know that sleep problems contribute to obesity, insulin resistance, diabetes and chronic disease. It might not be surprising to discover that sleep disturbance also negatively affects the brain; it’s linked to an increased risk of dementia and Alzheimer’s disease.
This is the topic we are diving into in today’s article. Keep reading to learn more about:
- The connections between sleep, brain health and aging
- What sleep has to do with Alzheimer’s disease
- Simple action steps to take for better sleep (and better health)
Let’s get started!
Sleep, Brain Health and Aging
Lack of sleep and disturbed sleep have consequences to neurology and cognition, including:
- Changes in mood and mental health
- Decrease in cognitive function and cognitive performance
- Slowed motor function
- Decreased alertness
- Decreased brain plasticity, or neuroplasticity (Source 1, 2)
These neurocognitive changes may be exacerbated in shift workers who switch sleep-wake cycle timing for work. (Source 3) In the rest of us, these may be more subtle at first, but accumulate over time. They may not be noticed from day to day as the body slowly adapts to changes in sleep patterns.
Sleep patterns change with age. Importantly, NREM (non-rapid eye movement or deep sleep) slow wave sleep declines from early adulthood to midlife, even as hours of sleep and REM sleep (rapid eye movement sleep) remain steady. (Source 4)
Note: Learn more about the stages of sleep and what normal sleep looks like in my article: Better Sleep.
In older adults, over age 65, it is common to see sleep disturbances and sleep disorders increase. These include:
- Increased early morning awakening
- Increased sleep latency (time it takes to fall asleep)
- Decreased sleep quality
- Difficulty maintaining sleep
These changes in sleep patterns observed with increased age correlate with changes in the brain including decreased plasticity, changes in hormonal levels, memory processing and cognitive performance. (Source 4, 5)
Sleep and Alzheimer’s Disease
Over 47 million people globally have dementia and Alzheimer’s disease is the most common form. These numbers are only projected to rise. Alzheimer’s-related deaths in the United States rose 71 percent from 2000 to 2013 and is the 5th leading cause of death in those over 65 years old. (Source 4, 6)
Alzheimer’s disease is a progressive, neurodegenerative disorder, resulting in the gradual decline of memory and cognition. The disease is characterized by the buildup of beta-amyloid, or amyloid beta, plaques in the brain. (Source 4)
Note: To learn more about Alzheimer’s disease, including risk factors, testing, prevention and treatment strategies, read my article: Causes of Alzheimer’s Disease.
Sleep disturbances are common in people with Alzheimer’s disease and yet sleep abnormalities are one of the earliest biomarkers of dementia. So, which came first? Alzheimer’s or poor sleep?
Emerging and compounding research suggests a bidirectional relationship between sleep and Alzheimer’s disease. Let me explain.
Amyloid beta, or beta-amyloid, is a waste product found in brain plaques related to impaired brain function in Alzheimer’s disease. Interestingly, sleep is important for clearing amyloid beta out of the brain and with disturbed sleep or not enough sleep these amyloid plaques build up. (Source 8)
One study looked at brain scans in participants after a full night of normal sleep and compared to brain scans after one night of sleep deprivation. The beta-amyloid was five percent higher after losing a full night of sleep! (Source 9)
Abnormal amyloid beta may accumulate 15 to 20 years prior to Alzheimer’s symptoms and correlates with the sleep changes that are seen prior to diagnosis. Another Alzheimer’s-related protein, called tau protein, also plays a role. Tau protein correlates with NREM slow wave activity and accumulates as this deep sleep declines. (Source 4)
Both amyloid and tau protein fluctuate along with the sleep-wake cycle. When there is disturbed sleep, and therefore more wakefulness, these proteins increase both because of an increase in production as well as a decrease in clearance. This buildup then leads to disturbed sleep, creating a cycle. (Source 4)
Sleep disturbances affect 25 to 66 percent of people with Alzheimer’s disease and as the disease progresses, sleep problems and sleep disorders become more debilitating. Then, these sleep abnormalities accelerate the Alzheimer’s disease process and cognitive decline. (Source 4, 5)
Sleep changes observed in Alzheimer’s disease include:
- Micro-architectural sleep alterations (changes in structure of sleep stages, such as decreases in time spent in slow wave sleep. Interestingly, similar changes are seen in Parkinson’s disease.) (Source 10)
- Nighttime sleep fragmentation
- Short sleep duration at night
- Increase in daytime napping
- Inversion of the sleep-wake cycle
- Other circadian rhythm disruptions (Source 11)
Another connection between Alzheimer’s disease has to do with obstructive sleep apnea, which affects 24 to 30 percent of older adults and is associated with diabetes and other metabolic disorders. Since sleep apnea affects sleep quality, it’s associated with an increased risk of Alzheimer’s disease and a risk factor for early onset of dementia. (Source 4)
Sleep apnea is also associated with the ApoE4 genotype. ApoE is a main cholesterol carrier in the brain and having the ApoE4 genetic allele is the strongest genetic risk factor for Alzheimer’s disease. (Source 4) Learn more about ApoE4 here.
How To Get Better Sleep
The effect of sleep on our brain cells is clear. Let’s talk about what we can do to improve poor sleep quality and make sure we are getting enough sleep each night.
Lifestyle and medical interventions that target sleep are important for maintaining quality of life with age as well as preventing or slowing cognitive decline.
Here are some sleep habits to implement:
- Get daylight during the day and darkness at night. Our circadian hormones, including cortisol and melatonin, are influenced by the light – or lack of light – that we are exposed to. The idea here is to mimic the natural changes in daylight you’d experience when camping or before electricity allowed us access to bright light after dark.
Then, when the sun goes down, dim indoor lights to mimic sunset and sleep in a cool, dark room. Consider blue light-blocking glasses if you are using screens at night or minimize screen time in the evening and focus on other activities. Darkness at night allows for natural melatonin production and fosters better sleep.
- Exercise. Exercise has so many benefits from physical health to mental health. It also helps to improve sleep. Exercise training has been shown to improve sleep quality in middle age and older adults. (Source 13)
We live in a culture where it’s common to become increasingly sedentary with age, which has negative consequences for health. Start small with walking or a local fitness class. If you already incorporate movement and exercise into your day, continue to make that habit a priority.
But, if you notice that exercise late in the day affects your sleep, make sure to do it in the morning.
- Supplements for improved sleep. If you are having troubled sleep, there are a lot of natural nutrients and other supplements that have been found beneficial for supporting sleep quality and duration.
Learn more about these options in my Guide to Sleep Supplements.
A couple of my favorite sleep supplements, that work in a wide range of cases, include both melatonin and GABA. Declining levels of melatonin, a main sleep-promoting hormone, is seen in the early stages of Alzheimer’s disease and supplementing with melatonin may help to restore sleep. (Source 14)
GABA, gamma aminobutyric acid, is the primary inhibitory neurotransmitter found in the brain and central nervous system. It helps calm down the nervous system and when the nervous system is calm, we can sleep. In Alzheimer’s disease there are alterations in GABA receptors and the enzyme that synthesizes GABA, which may be one mechanism by which Alzheimer’s disease impairs sleep. (Source 15)
Learn more about the role that GABA and melatonin play in sleep, along with more sleep tips here.
Core Med Science’s Liposomal Sleep Formula combines melatonin, GABA and glutathione, the body’s master antioxidant. These ingredients work together to support regular sleep patterns and protect the brain. As an alternative to powdered supplements that may be poorly absorbed, liposomal supplements easily move from the digestive system into the bloodstream and ultimately into cells, including brain cells.
If you are new to liposomal supplements, this sleep formula is a great place to start! You might just be a few pumps away from a good night’s sleep and all the benefits that it provides.