Quality deep sleep may compensate for the cognitive dysfunction and memory impairment of Alzheimer’s disease and could become the target of future therapies, especially in early and mild cases of the disorder. Sleep is like the brain’s plumbing system, removing harmful toxins and proteins associated with many types of dementia. Deep non-rapid eye movement (NREM) slow wave sleep is also necessary for consolidating our memories overnight, regulating our immune system and inflammatory responses and to enhance the functions of learning and memory.

The latest research on sleep’s association with dementia was published in the June 2023 issue of BMC Medicine. In it, investigators write that “sleep may represent a novel modifiable [cognitive] reserve factor and thus a promising treatment target” for Alzheimer’s disease. Specifically, the study determined that sufficient amounts of quality deep sleep supports memory preservation and cognition, even in those with relatively high brain levels of the waste proteins beta-amyloid and tau, which are linked to Alzheimer’s disease. Study participants experiencing less deep sleep—or more disrupted sleep in general—had poorer cognition.

If not flushed from the brain, beta-amyloids can begin to clump together, forming plaques—or, in the case of tau, neurofibrillary tangles—that lead to the eventual development of Alzheimer’s disease. Often, waste proteins start accumulating decades before symptoms of the disease manifest. So if you have trouble sleeping, it is worth looking into methods to increase healthy sleep, such a Cognitive Behavioural Therapy, or try some of the methods suggested by the Sleep Foundation.