Lack of Sleep Promotes Alzheimer’s by Preventing Critical Detoxification

By Dr. Mercola

Sleep disturbances are endemic in the US, where nearly 40 percent of adults report unintentionally falling asleep during the day in the past month, and five percent report nodding off while driving.1

Forty-five percent of teens also don’t get enough sleep on school nights and 25 percent report falling asleep in class at least once a week.

Lack of sleep has ramifications that go far beyond not feeling fully awake and refreshed during the day. There’s a price to pay in terms of health, both short- and long-term.

A number of studies have linked poor sleep or lack of sleep to an increased risk of Alzheimer’s for example, and one of the reasons for this has to do with the fact that your brain’s waste removal system only operates during deep sleep.

Your Brain Needs Sleep for Waste Removal

There’s no cure for Alzheimer’s disease, which makes prevention all the more important, and sleeping well appears to be an important part of prevention. Studies2,3 published in 2012 and 2013 revealed that your brain actually has a unique method of removing toxic waste. Amazon Prime (One Year... Check Amazon for Pricing.

This waste-removal system has been dubbed the glymphatic system,4,5,6,7,8 and operates in a way that is similar to your body’s lymphatic system, which is responsible for eliminating cellular waste products.

However, the lymphatic system does not include your brain. The reason for this is that your brain is a closed system, protected by the blood-brain barrier, which controls what can go through and what cannot.

The glymphatic system gets into your brain by “piggybacking” on the blood vessels in your brain. (The “g” in glymphatic is a nod to “glial cells”—the brain cells that manage this system.)

By pumping cerebral spinal fluid through your brain’s tissues, the glymphatic system flushes the waste from your brain back into your body’s circulatory system. From there, the waste eventually reaches your liver, where it’s ultimately eliminated.

The clincher is that this system ramps up its activity during sleep, thereby allowing your brain to clear out toxins, including harmful proteins called amyloid-beta, the buildup of which has been linked to Alzheimer’s.

During sleep, the glymphatic system becomes 10 times more active than during wakefulness. Simultaneously, your brain cells shrink by about 60 percent, allowing for greater efficiency of waste removal.

During the day, the constant brain activity causes your brain cells to swell in size until they take up just over 85 percent of your brain’s volume,9 thereby disallowing effective waste removal during wakefulness.

More recently, researchers discovered10 that the blood-brain barrier naturally tends to become more permeable with age, allowing more toxins to enter.

In conjunction with reduced efficiency of the glymphatic system, damage in both your brain and blood-brain barrier can start to accumulate at an increased pace. This deterioration is thought to play a significant role in the development of Alzheimer’s.

Sleep Is Not a Luxury, It’s an Essential for Good Health

As noted in a recent issue of Time Magazine:11

“Sleep, the experts are recognizing, is the only time the brain has to catch its breath. If it doesn’t, it may drown in its own biological debris… [Sleep researcher Dr. Sigrid] Veasey is learning that brain cells that don’t get their needed break every night are like overworked employees on consecutive double shifts–eventually, they collapse.

Working with mice, she found that neurons that fire constantly to keep the brain alert spew out toxic free radicals as a by-product of making energy. During sleep, they produce antioxidants that mop up these potential poisons.

But even after short periods of sleep loss, ‘the cells are working hard but cannot make enough antioxidants, so they progressively build up free radicals and some of the neurons die off…’

The consequences of deprived sleep, says Dr. Mary Carskadon, professor of Psychiatry and Human Behavior at Brown University, are scary, really scary.”

Omega-3 and Vitamin D May Control Brain Serotonin, Research Suggests

Speaking of brain health, recent research12,13 suggests that animal-based omega-3 and vitamin D can improve cognitive function and behavior associated with certain psychiatric conditions—including ADHD, bipolar disorder, and schizophrenia—by regulating your brain’s serotonin levels. As reported by ProHealth:14

“Many clinical disorders, such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, and depression share as a unifying attribute low brain serotonin.

‘In this paper, we explain how serotonin is a critical modulator of executive function, impulse control, sensory gating, and pro-social behavior,’ says Dr. Patrick. ‘We link serotonin production and function to vitamin D and omega-3 fatty acids, suggesting one way these important micronutrients help the brain function and affect the way we behave…’

Their paper illuminates the mechanistic links that explain why low vitamin D… and marine omega-3 deficiencies interact with genetic pathways, such as the serotonin pathway, that are important for brain development, social cognition, and decision-making, and how these gene-micronutrient interactions may influence neuropsychiatric outcomes.”

The omega-3 fatty acid EPA reduces inflammatory signaling molecules in your brain that inhibit serotonin release from presynaptic neurons, thereby boosting your serotonin levels. DHA also has a beneficial influence on serotonin receptors, by increasing their access to serotonin.

According to the researchers, optimizing your vitamin D along with the animal-based omega-3 fats EPA and DHA can help optimize your brain serotonin concentrations and function, and may help prevent and/or ameliorate psychiatric symptoms without adverse side effects. Serotonin is also an immediate precursor to melatonin, which has many important health benefits, including a reduced cancer risk.

Are You Getting Enough Sleep?

The latest sleep guidelines, based on 300 studies looking at the health effects of sleep, confirm that most adults need right around eight hours of sleep for optimal health. Forty percent of American adults get only six hours of sleep or less however, and 58 percent of teens—who need anywhere from eight to 10 hours—average only seven hours or less. This kind of sleep debt is a recipe for health problems down the road, and an increased risk of dementia is just one potential side effect.

Individual sleep requirements can vary, of course, based on age, life circumstances, and health status. So how can you be sure you’re getting the right amount for you? The following seven signs indicate you need to address your sleep schedule because you’re not getting enough sleep:15


Tips for Better Sleep

Small adjustments to your daily routine and sleeping area can go a long way toward ensuring you uninterrupted, restful sleep—and thereby better health. To get you started, check out the suggestions listed in the table below. For even more helpful guidance on how to improve your sleep, please review my “33 Secrets to a Good Night’s Sleep.” If you’re even slightly sleep deprived, I encourage you to implement some of these tips tonight, as high-quality sleep is one of the most important factors in your health and quality of life.


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