Five Hour or Less Sleep at Night Linked with Increased Risk of Dementia

Woman helping senior woman dress in her bedroomResearchers from the Brigham and Women’s Hospital have found an increased risk of dementia in those who sleep five hours or less a night. The study explored the connection between sleep disturbances and deficiencies among older adults and concluded that getting 7-8 hours of sleep could reduce the chance of a decline in mental cognition.
The study published in Aging also found associations between sleep disturbances and sleep deficiency with the overall risk of death.

Researchers used nationally representative data collected from older adults participating in the National Health and Aging Trends Study (NHATS) for the study. Survey data has been collected annually for NHATS since 2011 and includes Medicare beneficiaries 65 years and older.


A total of 2,610 participants answered sleep questionnaires in 2013 and 2014. Several characteristics of sleep were examined, including alertness, nap frequency, how long it took participants to fall asleep, sleep quality, sleep duration, and snoring. Patient outcomes were also collected, such as dementia and death from any cause for up to five years after the survey.

The study concluded that there was a strong relationship between several sleep disturbance and deficiency variables and dementia over time. The most notable piece from the study found that patients who routinely took 30 minutes or longer to fall asleep was associated with a 45 percent greater risk for incident dementia. Routinely experiencing less alertness, napping, poor sleep quality, and getting less than five hours of sleep a night was also associated with an increased risk of death.

The Importance of Sleep

“This prospective study reveals that sleep deficiency at baseline, when the average age of participants was 76 years old, was associated with double the risk of incident dementia and all-cause mortality over the next 4 to 5 years,” said senior author Charles Czeisler. “These data add to the evidence that sleep is important for brain health and highlight the need for further research on the efficacy of improving sleep and treating sleep disorders on the risk of Alzheimer’s disease and mortality.”

Within the United States, there are at least 5 million people currently living with age-related dementias. Although there are various forms of dementia, around 70 percent of cases are due to Alzheimer’s. With numbers of the disease rising, studies such as this are imperative to find the cognitive decline’s root cause. With more knowledge on the cause of dementia, preventative treatments could be utilized to help reduce cases.

The authors of the study call for further investigations into the relationships between sleep and dementia and death. While studies are ongoing, there should also be a focus on obtaining healthy sleep patterns in older adults.

Author Bio

Sarah began her interest in nutritional healing at an early age. After going through health problems and becoming frustrated with the conventional ways doctors wanted to treat her illness (which were not working), she took it upon herself to find alternative treatments. This led her to revolutionize her own diet to help her get healthier and tackle her health problems. She began treating her illness by living a more balanced lifestyle through healthy food choices, exercise and other alternative medicine such as meditation. This total positive lifestyle change led her to earn a diploma in Nutritional Therapy from Health Sciences Academy in London, England. Today, Sarah enjoys helping others by teaching healthy lifestyle changes through her personal consultations and with her regular contributions to the Doctors Health Press. Also, passionate about following her dreams in life, Sarah moved to France and lived in Paris for over 5 years where she earned a certification in beadwork and embroidery from Lesage (an atelier owned by Chanel). She then went on to be a familiar face sitting front row and reporting from Paris Fashion Week. Sarah continues to practice some of the cultural ways of life she learned while in Europe. They enjoy their food, and take the time to relax and enjoy many of life’s little moments. These are life lessons she is glad to have brought back home with her.


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