Expert recommends side‑sleeping to help protect against memory decline

A sleep position favouring the left or right side may help clear toxic proteins from the brain and reduce the risk of memory decline later in life, an industry expert said, adding that sleeping on the back or stomach could impede the brain’s waste‑clearance system.

Lev Fomchenkov, chief executive officer of online supplement reseller Cosmic Nootropic, cited research on the brain’s glymphatic system — a pathway that uses cerebrospinal fluid to flush metabolic waste from brain tissue — and argued that side‑sleeping allows better movement of that fluid than back or stomach positions.

"Most people think about sleep in terms of duration, i.e., getting those recommended eight hours," Fomchenkov said. "However, position may also play an important role in brain health." He said sleeping on either the left or right side appears equally effective in promoting cerebrospinal fluid circulation and the clearance of proteins such as beta‑amyloid and tau, which are associated with Alzheimer’s disease when they accumulate.

Researchers have identified two hallmark proteins implicated in Alzheimer’s: beta‑amyloid, which forms plaques between neurons, and tau, which forms tangles inside neurons. Studies of the glymphatic system show it is most active during sleep, when the space between brain cells expands by roughly 60 percent and cerebrospinal fluid can move more freely to remove waste. Fomchenkov said back‑sleeping may compress certain brain regions and stomach‑sleeping can interfere with spinal alignment, both of which could impede glymphatic clearance.

Health organizations and clinicians say the buildup of beta‑amyloid and tau does not happen rapidly but accumulates over years or decades and can interfere with neural communication, contributing to the memory problems associated with aging and dementia. Alzheimer’s disease, the most common cause of dementia, accounts for an estimated 60 to 70 percent of dementia cases, the Alzheimer’s Society says. There are currently about 982,000 people with dementia in the United Kingdom, and the society says the figure could rise to 1.4 million by 2040, with more than a third of those affected undiagnosed.

Medical experts note that sleep position recommendations commonly address joint and spinal comfort as well as breathing disorders. The Mayo Clinic says side‑sleeping generally helps maintain proper spinal alignment and keeps pressure off internal organs. Conversely, the clinic notes that sleeping on the back can aggravate obstructive sleep apnea because the tongue and jaw can fall back and crowd the airway. "Sleeping on the back means that your tongue and jaw can fall down and crowd your airway," said Dr. Lois Krahn, a Mayo Clinic sleep specialist, in commentary widely cited by clinicians.

Fomchenkov advised gradual adjustments for people who habitually sleep on their back or stomach. He recommended placing a pillow behind the back when first learning to sleep on the side to prevent rolling, using a small pillow between the knees to maintain hip and spine alignment, and choosing a pillow that fills the space between the shoulder and neck without tilting the head. He also suggested selecting a mattress that contours to the body while providing adequate support to avoid pressure points at the hips and shoulders.

"The goal is to wake up feeling rested, not stiff or sore," Fomchenkov said. "If your sleep position is causing discomfort, your brain won't get the deep, restorative sleep it needs for optimal detoxification." He added that most people who adopt such changes begin to adapt within a week or two.

The relationship between sleep position and long‑term brain health remains an area of active research. Scientists continue to study how sleep architecture, duration and quality interact with glymphatic clearance and the development of neurodegenerative disease. Medical authorities and sleep researchers stress that any single behavioural change should be considered alongside other established measures for brain and cardiovascular health, such as regular exercise, a balanced diet, management of vascular risk factors and treatment for sleep disorders.

For individuals concerned about dementia risk or sleep problems, clinicians advise consulting health professionals for personalised assessment, particularly when symptoms such as excessive daytime sleepiness, witnessed apnoeas or persistent neck and back pain are present. Public health organisations continue to emphasise early diagnosis and management of dementia, noting that current estimates and projections underline the growing public‑health burden posed by neurodegenerative conditions.