The Connection between a Lack of Sleep and the Increased Risk of Developing Dementia and Alzheimer’s Disease

Description of Alzheimer’s Disease and its Crippling Effects

One of the most feared diseases throughout developed nations is dementia, more specifically Alzheimer’s disease. Alzheimer’s disease is the most common type of dementia accounting for 60 to 80 percent of all dementia cases. Alzheimer’s disease progressively affects memory, thinking and behavior of mostly elderly people. In the early stages patients experience mild memory loss. In later stages of the disease individuals lose the ability to carry a conversation and respond to their environment.

The Connection Between Alzheimer’s Disease and Sleep Deprivation

Studies indicate there is a high correlation between a lack of sleep and whether you will develop Alzheimer’s disease. This study indicates that a persistent short sleep duration (6 hours or less) in midlife (50-60) is associated with an increased risk of developing dementia. Nowadays, people in the developed world have a much longer life span compared to in the previous decade. Additionally, the total average sleep time of the population has decreased significantly. As a result, the cases of Alzheimer’s disease have skyrocketed. Today, over 10 percent of the population over the age of sixty-five suffer from the crippling disease. The escalation of the disease is likely to continue all over the world without advances in diagnosis, prevention and therapeutics.

The Connection Between Diminished Deep NREM Sleep and Alzheimer’s Disease

The quality and amount of deep NREM sleep deteriorates as we age. This is described in detail on the page focused on The Importance of Sleep Throughout our Lives. This is why elderly people experience a significant decline in memory. For a patient with Alzheimer’s disease this disruption of deep sleep is exponentially higher. It also serves as an early warning sign of the condition. This is because significant deep sleep disturbance precedes the onset of Alzheimer’s disease by several years.

Furthermore, recent research illustrates that the disruption of deep sleep interacts with Alzheimer’s disease as a self-fulfilling, negative spiral. This is because a lower amount and quality of deep NREM sleep can initiate and/or accelerate the condition. It is not a coincidence that over 60 percent of patients with Alzheimer’s disease have at least one clinical sleep disorder such as insomnia.

The Effects of Alzheimer’s Disease On the Brain

Alzheimer’s disease is characterized by causing a buildup of a toxic form of protein in the brain called beta-amyloid. This harmful protein forms sticky clumps or plaques which are poisonous to neurons and kill the surrounding brain cells. These poisonous amyloid plaques only affect some parts of the brain. One common target is the middle part of the frontal lobe. This is the brain region that is essential for the electrical generation of deep NREM sleep. This illustrates why patients with Alzheimer’s disease have such drastically impaired deep NREM sleep. This is because the disease itself erodes the very region of the brain that normally generates this key stage of sleep.

The Role of the Glymphatic System for the Functioning and Sanitation of the Brain

Recent research illustrates an important link of Alzheimer’s disease with the functioning of the glymphatic system. The glymphatic system can be described as the clean-up crew of the brain. The glymphatic system functions by collecting and removing dangerous contaminants surrounding the neurons in our brain. This is done by bathing the brain with cerebrospinal fluid. It is during sleep that this neural sanitation work kicks into high gear. Especially during deep NREM sleep when this sanitation process is increased ten to twentyfold. Thanks to this deep cleaning, our brain can once again function efficiently when we wake up in the morning.

A Troubling Vicious Cycle Caused By Sleep Deprivation

An important toxic debris which is removed (among others) by the glymphatic system during sleep is amyloid protein. This is the poisonous element associated with Alzheimer’s disease. In the absence of sufficient sleep, this poisonous amyloid protein as well as other toxic debris accumulate in the brain. This buildup of toxic debris also occurs in the brain of healthy individuals if they are sleep deprived.

Consequently, inadequate sleep and the pathology of Alzheimer’s disease interact in a vicious cycle. This bidirectional relationship is covered in this study of 2013. Toxic amyloid plaques build up in the brain when a person is sleep deprived. This poisonous protein attacks and degrades deep-sleep-generating regions. This causes a reduction of deep NREM sleep. In turn, this lowers the ability of the glymphatic system to remove toxic amyloid from the brain at night. This leads to an even greater amyloid accumulation in the brain and so on and so forth.

Striking Examples of Historical Figures Who Developed Alzheimer’s Disease

Obtaining too little sleep throughout our life will significantly increase the risk of developing Alzheimer’s disease. Two prominent real-life examples are Margaret Thatcher and Ronald Reagan. They were two former heads of state that were very vocal and proud about sleeping only four to five hours a night. Both of them went on to develop Alzheimer’s disease.

Why Prioritizing Sleep Can Lower the Risk of Developing Alzheimer’s Disease

Unfortunately, insufficient sleep is only one of the several risk factors associated with Alzheimer’s disease. Therefore, it will not be the magical bullet that eradicates dementia. Nevertheless, prioritizing sleep across our life span and resolving sleep disorders such as insomnia will have an important impact on lowering the risk of developing Alzheimer’s disease. Additionally, getting adequate sleep is crucial for slowing down the cognitive decline and delaying the onset of the disease.

New Promising Methods to Increase the Amount and Quality of Deep NREM Sleep

Nowadays new types of promising methods are being developed to increase the amount and quality of deep NREM sleep. These alternative treatments have a lot of potential to help elderly people by lowering their risk of developing Alzheimer’s disease. Furthermore, these methods could prove beneficial to slow down the cognitive decline of the elderly and delay the onset of the crippling disease. More information can be found on the page focused on the Alternative Treatments for the Elderly.