Stony Brook University researchers imaged rodent brains and found that a lateral sleeping position more effectively removed "brain waste":
Sleeping in the lateral, or side position, as compared to sleeping on one's back or stomach, may more effectively remove brain waste and prove to be an important practice to help reduce the chances of developing Alzheimer's, Parkinson's and other neurological diseases, according to researchers at Stony Brook University.
By using dynamic contrast magnetic resonance imaging (MRI) to image the brain's glymphatic pathway, a complex system that clears wastes and other harmful chemical solutes from the brain, Stony Brook University researchers Hedok Lee, PhD, Helene Benveniste, MD, PhD, and colleagues, discovered that a lateral sleeping position is the best position to most efficiently remove waste from the brain. In humans and many animals the lateral sleeping position is the most common one. The buildup of brain waste chemicals may contribute to the development of Alzheimer's disease and other neurological conditions. Their finding is published in the Journal of Neuroscience.
[...] "It is interesting that the lateral sleep position is already the most popular in human and most animals – even in the wild – and it appears that we have adapted the lateral sleep position to most efficiently clear our brain of the metabolic waste products that built up while we are awake," says Dr. Nedergaard. "The study therefore adds further support to the concept that sleep subserves a distinct biological function of sleep and that is to 'clean up' the mess that accumulates while we are awake. Many types of dementia are linked to sleep disturbances, including difficulties in falling asleep. It is increasing acknowledged that these sleep disturbances may accelerate memory loss in Alzheimer's disease. Our finding brings new insight into this topic by showing it is also important what position you sleep in," she explained.
Dr. Benveniste cautioned that while the research team speculates that the human glymphatic pathway will clear brain waste most efficiency when sleeping in the lateral position as compared to other positions, testing with MRI or other imaging methods in humans are a necessary first step.
Extracellular aggregates are #6 on the SENS aging damage checklist, and all you have to do to get rid of them is sleep on your side (allegedly, or if you are a rat).
(Score: 0) by Anonymous Coward on Sunday August 09 2015, @05:38PM
It's likely that each species, indeed groups within each species, adapts so that the waste is efficiently removed in the sleeping position into which the individuals naturally assume.
I can't ever remember seeing an adult cat asleep on its back.
(Score: 1, Funny) by Anonymous Coward on Sunday August 09 2015, @05:53PM
did you know? there are pictures of cats on the internet: https://www.google.de/search?q=cat+sleeping+on+its+back [google.de]
(Score: 0) by Anonymous Coward on Sunday August 09 2015, @06:25PM
Speaking of adapting I wonder why so many humans snore (even the nonobese ones). What's the benefit? Speed healing like purring? http://www.telegraph.co.uk/news/worldnews/northamerica/usa/1326953/Revealed-how-purrs-are-secret-to-cats-nine-lives.html [telegraph.co.uk]
Otherwise it would seem like a significant disadvantage.
(Score: 2) by frojack on Sunday August 09 2015, @06:47PM
Speaking of adapting I wonder why so many humans snore
Loud snoring resonating in the cave scared predators away?
Seriously, some random/accidental traits tend to survive if they are simply non-harmful, even in the absence of any obvious benefit.
No, you are mistaken. I've always had this sig.
(Score: 2) by stormwyrm on Monday August 10 2015, @01:55AM
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by Yog-Yogguth on Monday August 10 2015, @09:55AM
“…it only starts becoming problematic after people are long past reproductive age…”
I'm afraid that is completely untrue according to my experience, I've lived in dormitories and barracks and shared sleeping quarters, I was young as was everyone else and snoring was a huge problem, their snoring for me and my snoring for them :(
Slightly later in life my wives (not simultaneous ha-ha) also snored once in a while (as did I).
None in those examples were obese or past the reproductive age.
Now I'm old enough to wake up if I snore (luckily I almost only seem to snore if I fall asleep while on my back which means I fell asleep almost immediately before turning over, so if I suspect I'm that far gone into exhaustion I try to remember to avoid laying down on my back), it's quite disorienting to wake up from ones own snoring because one doesn't immediately realize what happened or where the strange noise disappeared off to XD
Bite harder Ouroboros, bite! tails.boum.org/ linux USB CD secure desktop IRC *crypt tor (not endorsements (XKeyScore))
(Score: 2) by stormwyrm on Monday August 10 2015, @12:59PM
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by Yog-Yogguth on Monday August 10 2015, @09:16PM
Ah okay, yeah I missed the point you were making. I could quibble but won't :)
Bite harder Ouroboros, bite! tails.boum.org/ linux USB CD secure desktop IRC *crypt tor (not endorsements (XKeyScore))
(Score: 0) by Anonymous Coward on Sunday August 16 2015, @11:33AM
It is silly to think that snoring is a genetic trait. Beware the cult of the genome.
(Score: 0) by Anonymous Coward on Sunday August 09 2015, @08:10PM
It's likely that each species, indeed groups within each species, adapts so that the waste is efficiently removed in the sleeping position into which the individuals naturally assume.
And what defines "naturally?"
I think it is much more likely that side-sleeping was an evolutionary advantage so the people who didn't side-sleep were not as effective as passing on their genes.