Sleeping on your Side Washes Your Brain the Best

Sleeping on your Side Lowers Risk for Alzheimer’s

Reference: Jr Neuroscience August 2015, New York Times

August 17, 2015

Sleeping on your side may reduce your risk for Alzheimer’s!   How so? Well, the above referenced study was done in rats, so we aren’t certain it works in humans, but it appears to reflect what happens in all mammals. The evidence of what happens when we sleep is increasing.

Sleep is your brain on “flush”. It’s cleaning itself and washing away accumulated toxins. When you are awake, your brain is using up to 50 different neurotransmitters to conduct its business of thinking and surviving.   Those neurotransmitters are sent out along very long, tiny thin wires called axons to connect with other cells all over your brain.   Little packets of those chemicals are secreted on one side of synapse to cause a reaction on the other side. The chemicals may be picked back up, or may be digested.   At the end of the day, you are left with a lot of chemical breakdown products a long way away from where they were manufactured. The wires (axons) are so thin that there is a big problem transporting the waste products back.   You feel tired and ready to sleep.   If you don’t get sleep, you start to slow down your thinking, make errors and within a few days, hallucinate before you die.

That’s where the glymphatic system comes in.   It was described only in the last few years when it was discovered to actually connect the lymph system to the brain. What is more dramatic is what happens when you sleep.   The glymphatic system swells in size (as much as 60%) and the axons shrink in size. This allows for a huge increase in the flow of lymph fluid while you sleep. The amount of flow that can be accommodated by that change in fluid size is as much as 10 fold.

It’s as though your brain can either play in the band, or dance to the music, but it can’t do both at the same time. It can think and function as what we call awareness, or it can flush and cleanse itself in what we call sleep.   But toxins are building up every second you are awake, and eventually have to be flushed out.

So, just what did this study show?   Rats, when sleeping on their sides, are much more efficient at cleansing their brains than when they sleep on their backs or stomachs. Now all mammals naturally sleep on their sides predominantly.

What gets flushed out is not just the chemical break down product but also β-amyloid, the protein that is found concentrated in Alzheimer’s.   Dr. Helene Benveniste used MRI technology with kinetic modeling to measure the exchange rate of the cerebrospinal fluid with the glymphatic system fluid.   With fluorescence microscopy and radioactive tracing, they were able to see the change in fluid flow during wakefulness and sleep by looking directly at the brains of the anesthetized rats.   This is another study confirming the existence of the glymphatic system, and building on that to show that it is most efficient when you lay on your side.

Lots of dementia related diseases have sleep disorders as part of their pathology. Alzheimer’s is no exception.   And there appears to be links between chronic sleep loss and Alzheimer’s.

WWW. What will work for me.   I like sleeping on my side but my shoulder aches if I don’t have two pillows to support me.   I’m going to pay attention to see if I get more restful sleep when I lay on my side or on my stomach, and avoid my back.

 

Pop Quiz

  1. During sleep, the fluid flow of your brain’s drainage system increases 60%. T or F

False. The size of the vessels increase in cross section 60% but that means the flow can increase as much as 10 fold.

  1. Your brain can either cleanse itself or think, but can’t do both at the same time. T or F

True

  1. Your brain has a system of fluid channels that are connected to the lymph system out of which fluid flows during sleep, now called the glymphatic system. T or F

True

  1. Lack of sleep means toxins are building up? T or F

True. That may be sleep’s most important action.

  1. Sleep flushes out β-amyloid, the protein that accumulates in Alzheimer’s. T or F

True