Early Alzheimer’s disease associated with too little or too much sleep.
New research, from data collected in the Nurses’ Health Study, has found that very long or very short sleep durations over time may contribute to cognitive decline and changes of early Alzheimer’s disease.
With 7 hours considered “average”, participants who slept 5 hours per day or less and participants who slept 9 hours per day or more had lower average cognition than those with average sleep duration. In the women studied, too little or too much sleep was equivalent to cognitive aging of 2 years.
An early biomarker of Alzheimer’s disease brain changes was measured in the blood of a subset of subjects. There was a decrease in the ratio of these blood protein markers in subjects that slept either more than or less than 7 hours per night.
The long term effects of too little or too much sleep may be more important than we have previously realized.