Expert reveals the best sleep position to protect against memory decline – and it’s bad news for those who like to lie on their back

Whether it’s curled up in a ball or a spread-out starfish, everyone has a favourite sleeping position. 

But according to a brain health expert, how you sleep could play an important role in staving off memory loss in later life.

And it’s bad news for people who like to lie on their back in bed. 

Lev Fomchenkov, CEO of online supplement reseller Cosmic Nootropic, says side-sleeping is the best position for brain health. 

This arrangement better flushes away toxins from the brain that contribute to memory decline and Alzheimer’s disease, he claims. 

And it doesn’t matter if you prefer facing right or facing left, as both side-sleeping options are optimal for boosting brain health, he said. 

‘Most people think about sleep in terms of duration, i.e., getting those recommended eight hours,’ said Fomchenkov. 

‘However, position may also play an important role in brain health.’

According to a brain health expert, how you sleep could also stave off memory loss in later life – and it’s bad news if you lie on your back (file photo)

The expert points to the glymphatic system – the brain’s waste clearance pathway – which is most active when we sleep. 

This system uses cerebrospinal fluid, a clear liquid which surrounds the brain, to flush out toxic proteins that accumulate in brain tissue.

An abnormal build-up of two of these proteins in and around brain cells is thought to cause Alzheimer’s disease, the most common cause of dementia. 

One of the proteins involved is called beta amyloid plaques, deposits of which form plaques around brain cells, while the other protein is called tau, deposits of which form tangles within brain cells.

According to the expert, side-sleeping (either on your left or right side) allows better movement of fluid to flush out these proteins, compared with back or stomach sleeping.

‘When you sleep on your side, gravity actually helps the cerebrospinal fluid circulate more effectively through your brain tissue,’ said Fomchenkov. 

‘This improved flow means better clearance of those harmful proteins that can accumulate and contribute to cognitive decline.

‘This includes proteins like beta-amyloid and tau, which are linked to Alzheimer’s disease when they build up over time.’ 

The glymphatic system (pictured in this symmetrical rendering) uses cerebrospinal fluid, a clear liquid which surrounds the brain, to flush out toxic proteins that accumulate in brain tissue

And it doesn’t matter if you prefer facing right or facing left, as both side-sleeping options are optimal for boosting brain health

During sleep, the space between your brain cells expands by about 60 per cent, allowing cerebrospinal fluid to flow more freely and wash away waste. 

But back-sleeping can compress certain brain regions, while stomach-sleeping often restricts proper spinal alignment, both of which can impede the glymphatic system’s function. 

When your brain can’t effectively clear these waste proteins during sleep, they begin to accumulate in areas responsible for memory formation and retention. 

Beta-amyloid plaques and tau tangles, the hallmarks of Alzheimer’s disease, don’t appear overnight, but build up gradually over years or even decades.

‘Think of it like not taking out your trash for weeks – eventually, the accumulation becomes problematic,’ said Fomchenkov. 

‘In the brain, this toxic buildup interferes with neural communication and can lead to the memory problems we associate with aging and dementia.’

When side-sleeping, Fomchenkov does advise people to keep a small pillow between the knees to help maintain proper hip and spine alignment. 

If switching to side-sleeping, put a pillow behind the back when lying on your side to prevent rolling, and after a week or two the body will begin to adapt to the new position naturally.

Artist’s impression shows amyloid plaques forming between neurons, otherwise known as nerve cells (stock image)

Already, the best position to sleep is a subject that divides experts and the public alike, but the debate usually focuses on posture and joint pain. 

Sleeping on your side is generally recommended by experts as long as the body and the head are both facing sideways, as it helps to keep pressure of joints, maintain proper spinal alignment and prevent pain. 

Sleeping on your side also keeps pressure off internal organs and promotes healthy blood flow, according to the respected Mayo Clinic in Minnesota. 

Meanwhile, sleeping on your back, facing the ceiling, is also usually recommended to stave off joint pain, but it can sometimes make neck pain worse, not to mention exacerbate other issues. 

Mayo Clinic experts say sleeping on your back is actually the worst sleeping position, especially if you have sleep apnea – which is when your breathing stops and starts while you sleep. 

‘Sleeping on the back means that your tongue and jaw can fall down and crowd your airway,’ said Mayo Clinic sleep specialist Dr Lois Krahn.

Lastly, sleeping on your front is generally considered the most unhealthy because it can inhibit breathing and cause irregular curvature of the spine.