If you sleep less than 5 hours at night, “the risk of dementia may be doubled.”

A new study doubles the risk of developing dementia if you sleep less than five hours at night.

Researchers at Brigham and Women’s Hospital in Boston examined data on 2,812 adults in the United States over the age of 65.

They found that “very short” sleep time, defined as 5 hours or less, doubled the risk of dementia compared to the “recommended” time of 7-8 hours.

This study supports previous studies that sleep deprivation essentially “stages” forms of dementia such as Alzheimer’s disease.

This study does not investigate the reason behind the link, but the lack of proper rest may prevent the brain from removing the toxins that cause a continuous decline in brain function.

Researchers emphasize “the urgent need to identify specific recommendations for improving sleep in the elderly.”

According to the NHS, most adults need 6-9 hours of sleep each night, but the US Sleep Foundation recommends 7-8 hours of sleep per night for people over the age of 65.

“Our findings clarify the link between sleep deprivation and the risk of dementia and confirm the importance of efforts to ensure that older people get enough sleep every night,” said the lead author of the study. Said Dr. Rebecca Robins, Department of Sleep and Circadian Rhythm Disorders, Brigham and Women’s Hospital. ..

According to the World Health Organization, about 50 million people worldwide suffer from dementia, and nearly 10 million new cases occur each year.

Alzheimer’s disease is the most common form of dementia and can contribute to 60% to 70% of cases of dementia.

According to the Alzheimer’s Disease Association in the United Kingdom, more than 920,000 people live with dementia in the United Kingdom. This number is expected to increase to more than one million by 2024.

“Both sleep disorders and abnormal sleep times can often be corrected, but they are associated with the development and progression of Alzheimer’s disease,” says Brigham researchers.

Recent studies have also suggested that adults over the age of 65, who report good sleep health, such as awakening and refreshing mood, exhibit better cognitive function.

According to the Sleep Foundation, more sleep disorders have been reported among older people than any other age group.

For their study, researchers used nationally representative data collected from older people participating in the National Health and Aging Trends Study (NHATS).

NHATS is a longitudinal study of the beneficiaries of Medicare, a US National Health Insurance program that collects data. Every year since 2011.

In 2013 and 2014, a sample of 2,610 participants responded to the sleep questionnaire. The questionnaire included several characteristics of sleep disorders and sleep deprivation, such as awakening, frequency of naps, time to fall asleep, and snoring.

Also asked about sleep time classified as “recommended” period (7-8 hours), short (6-7 hours), “very short” (less than 5 hours), or “long” (or more). Was done. 9 hours).

Participants were also asked about sleep quality on a five-point Likert scale, from “very bad” to “very good.”

Experts also collected information on patient outcomes such as dementia and death from any cause for up to five years after the study.

Overall, they found a strong link between sleep disorders and deficiency and dementia, as well as an overall risk of death over time.

Taking more than 30 minutes to fall asleep was associated with a 45% increased risk of developing dementia.

There is also an increased risk of death if you have difficulty staying awake, taking regular naps, reporting poor sleep quality, or sleeping for less than 5 hours per night.

“This prospective study found that baseline sleep deprivation, with an average age of 76 for participants, was associated with twice the risk of developing dementia and death from all causes over the next 4-5 years. “We have made it clear,” said the senior research author. Charles Czeisler, Head of Sleep and Circadian Rhythm Disorders.

“These data add evidence that sleep is important for brain health and highlight the need for further research into improving sleep and the effectiveness of treatment for sleep disorders against the risk of Alzheimer’s disease and mortality. . “

Researchers acknowledge that their study has some limitations-especially because it did not establish a cause and effect, so it is definitive that sleep deprivation and poor sleep quality cause dementia. I can not do it.

“Future studies need to be done to investigate the causal relationship between sleep and dementia development and mortality from all causes in the elderly,” said a study published in the journal. aging..

However, this study supports previous findings. Last year, sleep inefficiencies or too long awakening in bed increased the chances of cognitive decline by 24%.

Studies published in Journal of Neurology, Neurosurgery, & PsychiatryDid not determine if or how sleep disorders directly cause cognitive decline or dementia.

However, Dr. Wei Xu, principal research author at Qingdao University in China, said sleep problems can lead to cognitive impairment by causing inflammation of tissues of the central nervous system, including the brain and spinal cord. ..

Sleep disorders can also cause cognitive problems by causing or exacerbating hypoxia in the brain-reduced oxygen supply in the brain, Dr. Xu added.

In addition, sleep disorders reduce the efficiency of the brain in removing waste products and can contribute to the loss of brain cells or the atrophy of important areas of the brain.

“Changes in sleep habits may actually set the stage for dementia,” said Dr. Jeffrey Iriff, a brain scientist at Oregon Health & Science University.

In 2013, Dr. Iriff participated in a study that found that too little sleep could accelerate the development of sticky amyloid plaques associated with Alzheimer’s disease.

The study revealed a purification process that takes place in the brain during sleep.

Dr. Iriff said: “The fluid normally outside the brain-cerebrospinal fluid-it’s a clear, clear fluid-actually begins to recirculate in and through the brain along the outside of the blood vessels.”

on the other hand, 2019 study People who slept for more than 9 hours per night were found to have significantly reduced memory and language skills, which are early markers of dementia.