MONDAY, July 20, 2026 (HealthDay News) — Snoring at night might not just disrupt a partner or pets; it could also impact memory function and dementia risk.

A new study in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association examined the link between obstructive sleep apnea (OSA), memory and dementia risk. Researchers used cognition testing on adults aged 40 to 77 to compare people with and without the sleep disorder.

Those with untreated OSA had worse cognition and memory function. They also had an increased dementia risk. 

If the sleep apnea was treated, however, that changed. Adults who managed their apnea had brain testing results on par with adults without it. 

Obstructive sleep apnea occurs when the airway partially collapses or narrows during sleep, causing snoring and affecting breathing. Doctors have long suspected it may be a factor in the development of dementia. OSA disrupts oxygen flow and interrupts sleep cycles, which can affect brain function. 

People with obstructive sleep apnea often have other risk factors for dementia, such as obesity, high blood pressure and high cholesterol. As a result, it can be challenging to know which factor contributes most to memory and thinking skills.

The study helped to answer that by controlling for these other risk factors. Even outside other risks, OSA was still linked to lower cognition and increased dementia risk.

Researchers also looked at how the APOE e4 allele, a gene known to increase the risk of Alzheimer's, affected dementia risk with obstructive sleep apnea. People who had OSA had a higher risk of dementia than people who had the gene but no OSA. 

“Sleep apnea is common, frequently undiagnosed, and highly treatable, yet it is not often considered in discussions about dementia risk,” said lead author Gabriel Abdelmessih, a doctoral student in clinical neuropsychology at Monash University in Australia.

“Our findings suggest that identifying and managing sleep apnea in midlife may represent an important opportunity to support long-term brain health," he added in a news release.

Treatment options for OSA include using a continuous positive airway pressure (CPAP) device at night, weight loss, lifestyle changes or custom oral devices. 

OSA can be diagnosed through a sleep study. 

More information

To find out more information about brain health and dementia risk, visit the Alzheimer's Society.

SOURCE: Monash University, news release, June 30, 2026