We all know that we should get our rest. Our mothers told us that when we were kids. Beauty experts call it "beauty sleep" because it's so beneficial to our skin. Our doctors tell us to get plenty of it when we have a cold or the flu. And it's on every checklist for healthy living that you'll ever read.

We know we need it but sometimes knowing isn't enough. That's probably why sleeping pills are some of the most common over-the-counter medicine purchases. After all, lying in bed telling ourselves that we need to get to sleep isn't very conducive to falling asleep!

Our brains need rest, too

Now scientists have found another reason for why we need enough of that sometimes elusive sleep. Besides the rest of our body healing itself while we sleep, it turns out our brain does, too. Some researchers have discovered that those nasty neurotoxins that trigger neurodegenerative conditions like Parkinson's disease, Alzheimer's, and dementia (amongst others) are eliminated from our bodies while we sleep. Because the neural cells of our brain are so sensitive to toxins, it's imperative that they are removed as quickly as possible to protect precious brain cells. A recent study suggests that sleeping on our side helps our body get rid of those damaging waste products more effectively.

Maintaining a clean brain

Typically, our lymphatic system takes care of filtering out toxic wastes from our body. The mind, however, has its unique method of eliminating waste products. Cerebrospinal fluid (CSF) circulates our brain, picking up toxic wastes and leaving behind nutrients in their place. It then exchanges those toxins with the interstitial fluid (ISF). The glymphatic pathways regulate this process, and now scientists have discovered that how we sleep affects how efficiently this whole system works.

The whole time we're awake, the central nervous system produces toxic byproducts as a result of its normal metabolic processes; these toxins accumulate in the ISF. Beta-amyloid peptide and tau proteins are two of these toxins that are believed to trigger Alzheimer's symptoms when abnormal amounts are present. The concentrations of these byproducts in our bodies is highest when we're awake and lowest while we sleep. That indicates that more of these toxins come about while we're awake and more of them exit once we're asleep.

Sleeping position matters

Now scientists have discovered that our sleeping position affects how quickly these toxic waste products leave our brains. In an experiment on sleeping rodents, the glymphatic pathway worked more efficiently, and cleared toxins more quickly, in the rodents that rested on their sides rather than their backs or stomachs. Interestingly, sleeping on our sides is the way most humans and many animals choose to sleep. We need further studies to figure out how, and why, sleeping on our sides has such a fantastic effect on the efficient working of the lymphatic system.

Faster is better

Some of the toxins in our brain are comparatively large and consequently take longer to filter out than smaller molecules. The more efficiently the lymphatic system is working, and the faster the flow through it, the sooner these larger molecules will be washed out and away from the brain. Think of it like spilling something in the sink—it washes away more quickly when you turn the water on full blast instead of just a trickle. The rate of toxin removal from the brain even allows scientists to detect early warning signs of neurodegenerative, debilitating diseases and calculate their progression.

Adequate downtime is essential

There are some significant issues associated with our brain's lack of sufficient downtime: those suffering from a lack of sleep show clear evidence of brain impairment. That impairment shows up in a range of declining cognitive functions. Our reaction times slow down, it's difficult for us to learn and remember new information, and we're more likely to suffer from seizures. People who have really severe insomnia have even died!

Toxic waste is, well, toxic

But can sleep help prevent these neurodegenerative diseases? Like insomniacs, anyone suffering from a lack of downtime for their brain will experience a decline in brain function. A decrease in the proper functioning of the brain's toxic waste removal system will have the same effect. A recent study of patients suffering from traumatic brain injuries discovered that their glymphatic pathways were compromised. Their brains were up to 60% less efficient at removing neural toxic waste than in people whose minds weren't injured.

As a result of their compromised waste removal system, imaging studies showed that their brains had excess accumulations of tau protein. Tau proteins are a known risk factor for the early appearance of Alzheimer's disease and dementia. Scientists believe that neural cell damage resulting from any impairment to the functioning of the glymphatic pathway increases a person's chances of developing a degenerative brain disease. These diseases include Parkinson's disease, Alzheimer's, dementia, coma, or even death.

Improving the neural waste removal system

A better understanding of the brain's marvelous waste removal system could help explain the reasons neural diseases develop and progress and how to slow down or even stop them. Once scientists have a better idea of what's going on, they might be able to develop medicines that can improve how the glymphatic pathways function. Then maybe patients with compromised neural systems could have a better quality of life. It might even be possible to stop neural decay from progressing at all!

Can sleep help prevent neurodegenerative diseases?

According to recent studies, it’s very likely. Regardless, we can all do our part by making a conscious effort to get more sleep—while falling asleep, and staying asleep, on our sides! It seems like scientists are proving that maybe mother did know best all those years ago when she told us how important it was to get our rest. Adequate sleep does help reduce our chances of developing Parkinson's disease, Alzheimer's, and dementia. Listen to Mother and don't let your sleeping habits, or lack of sleep, put you at risk for these neurodegenerative disorders.