The Connection Between Lack of Sleep and Alzheimer's Disease

Welcome back to our regular series with certified sleep educator Terry Cralle, MS, RN. In this post, Cralle explains the relationship between Alzheimer’s disease and sleep and shares tips for protecting your memory as you age.

In a previous column, I shared 15 reasons to make sleep a priority in your life-one of the major reasons being that sleep may help you maintain your memory later in life. In fact, research shows a correlation between lack of sleep and Alzheimer’s disease, the most prevalent form of dementia.

Alzheimer’s disease and sleep: what’s the connection?

The key connection between dementia and sleep lies in the billions of neurons in your brain. Neurons are specialized cells that process and transmit information via chemical and electrical signals. Neurons send messages between different parts of your brain and from your brain to your muscles and organs.

Unlike other cells in your body, neurons have evolved to live a long time-more than a hundred years. As they age, neurons must undergo constant maintenance and repair to function properly. And unfortunately for those of us who like to skimp on sleep, research has demonstrated that neurons literally cannot function properly when you don’t get enough rest.

In a healthy aging process, your brain shrinks to some degree, but you don’t lose large numbers of neurons. However, in those who have dementia, and Alzheimer’s disease in particular, many neurons stop functioning and lose connections with other neurons, causing problems with thinking, behavior, and memory.

Beta-amyloid and tau are two proteins in the brain associated with neuron deterioration and Alzheimer’s disease. They accumulate in the brain daily but are typically flushed out of during slow-wave, or deep sleep, the stage of sleep that helps us to consolidate memories.

Sleep problems are associated with higher levels of both proteins, which are thought to be waste products from the energy used when brain cells communicate. When abnormally high levels of beta-amyloid protein clump together, plaques are formed, collecting between neurons and damaging processes needed by brain cells to function properly.

When excess tau accumulates, it forms tangles inside neurons. These tangles interfere with the communication between neurons and ultimately cause dysfunction. Elevated tau, a hallmark of Alzheimer’s disease, is associated with cognitive decline and brain damage.

So, does sleep deprivation cause Alzheimer’s disease?

It’s thought that the interaction between sleep and Alzheimer’s disease is circular in nature. Researchers aren’t yet sure which way the interaction goes-whether poor sleep causes or exacerbates Alzheimer’s disease, or if the plaques that form in the brains of people with Alzheimer’s disease disrupt sleep.

There is some clinical evidence to consider. Research conducted at the Washington University School of Medicine reports that sleep is disrupted in people with early Alzheimer’s disease but who don’t yet have the memory loss or other cognitive problems characteristic of full-blown Alzheimer’s disease.

Additionally, people diagnosed with certain sleep disorders, such as insomnia and sleep apnea, are more likely to develop dementia symptoms. That makes sense since there is evidence showing the brain’s ability to remove toxic waste buildup only operates during deep sleep.

How to sleep better (and protect yourself against Alzheimer’s disease)

Alzheimer’s disease shouldn’t be considered an inevitable result of aging. Although there is no known cure for Alzheimer’s disease, there are a few steps you can take to prevent or delay its onset. Research suggests improving sleep quality may potentially slow the progression of the disease.

Increasing evidence points to the fact that getting at least 7 to 8 hours of quality sleep is essential for brain health and function, and that sleep is critical for removing harmful beta-amyloid and tau proteins.

You can take the first step toward brain health by setting a sleep schedule that includes enough time for rest and then work to maintain that schedule. A schedule reinforces your body’s sleep-wake cycle. Other sleep-inducing steps you can take include:

Ensuring your bedroom is dark, cool, and quiet-all essential factors for optimal rest.
Investing in a comfortable mattress and bedding.
Unplugging from all electronic devices at least 30 to 60 minutes prior to bedtime.
Maintaining a consistent, reproducible, relaxing bedtime routine that provides your body and mind time to transition from wake to sleep.
Consider sleep a vital sign-at every age. Don’t ignore sleep problems, and be sure that sleep is addressed at every family member’s healthcare encounter.