Outlive: The Science and Art of Longevity

by Peter Attia

But sleep disturbances, in turn, may help create conditions that allow Alzheimer’s to progress. Insomnia affects 30 to 50 percent of older adults, and there is ample research showing that sleep disturbances often precede the diagnosis of dementia by several years; they may even appear before cognitive decline. One study linked poor sleep quality in cognitively normal people with the onset of cognitive impairment—just one year later. Meanwhile, superior sleep quality in older adults is associated with a lower risk of developing MCI and Alzheimer’s disease, and with maintaining a higher level of cognitive function. Successfully treating sleep disturbance may delay the age of onset into MCI—by about eleven years, according to one study—and may improve cognitive function in patients already diagnosed with Alzheimer’s disease.