Reduced slow-wave sleep associated with elevated dementia risk in aging, reveals study
Lack of deep sleep, known as slow-wave sleep, may heighten the risk of dementia Enhancing the quality and duration of deep sleep could potentially mitigate this risk
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Recent research suggests that the reduction of slow-wave sleep with age can potentially heighten the likelihood of developing dementia.
According to Matthew P. Pase, the senior author of the study published in JAMA Neurology, aging is linked to a decrease in slow wave sleep, the deepest stages of sleep. In an email, Pase, who is an associate professor of psychology and neurology at Monash University in Australia, also mentioned that individuals with significant declines in slow wave sleep over time have a higher risk of developing dementia during the next 17 years of follow-up.
During the third stage of sleep, known as slow-wave sleep, the body eliminates substances from the brain that are undesirable or potentially detrimental, including the beta-amyloid protein associated with Alzheimer's disease. Dr. Richard Isaacson, the research director at the Institute for Neurodegenerative Diseases in Florida, stated that this deep sleep is believed to be extremely beneficial for brain health. Please note that Dr. Isaacson did not participate in the study.
Purpose is an important component of health, experts said.
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Feeling a sense of purpose drops after dementia, new study shows
The researchers sought to determine the correlation between long-term decreases in slow-wave sleep and the risk of dementia in individuals. Conversely, they also investigated whether dementia-related activities in the brain could lead to a decrease in this particular type of sleep.
According to Pase, the findings indicate that persistent reductions in slow wave sleep, rather than individual variations at a specific moment, play a crucial role in forecasting the likelihood of developing dementia.
The study involved 346 individuals with an average age of 69 who had taken part in the Framingham Heart Study. Two overnight sleep studies were conducted, one between 1995 to 1998 and the second between 1998 to 2001, during which their sleep patterns were monitored. The Framingham Heart Study, initiated by the US National Heart, Lung and Blood Institute in 1948, focuses on identifying common factors contributing to cardiovascular disease.
Additionally, the researchers explored whether any changes in the amount of slow-wave sleep experienced by the participants were linked to the development of dementia up to 17 years after the completion of the sleep studies.
By the time, 52 individuals had received a diagnosis of dementia. Each annual decrease in slow-wave sleep percentage was associated with a 27% rise in the likelihood of developing dementia and a 32% higher risk of developing Alzheimer's disease dementia. The decline in slow-wave sleep accelerated from the age of 60, reached its highest point between the ages of 75 and 80, and then decreased. Individuals who experienced a decline in this deep sleep were more prone to cardiovascular disease, taking sleep-impacting medications, and carrying the APOE ε4 allele gene, which increases the risk of Alzheimer's.
"This study once again highlights the significance of sleep quality on an individual's vulnerability to cognitive decline and dementia," commented Isaacson, emphasizing its importance. "It is crucial to not only consider the duration of sleep each night, but also strive to closely monitor and enhance sleep quality."
Deep sleep and its association with dementia
The May study is not the first to identify these connections. In fact, it revealed that a decrease in deep sleep by 10% resulted in an increase in tissue damage, particularly in the formation of connections between brain cells.
According to the Alzheimer's Association, 14% of Hispanic people 65 and older have Alzheimer's dementia, compared to 10% of White older adults.
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Research indicates that older Hispanic individuals have a higher likelihood of developing Alzheimer's compared to older White individuals. However, the authors of the latest study clarify that it does not conclusively demonstrate a causal relationship between the loss of slow-wave sleep and dementia. They also suggest the possibility of dementia-related processes in the brain leading to sleep disturbances, which one expert described as a "vicious cycle."
According to Dr. Rudolph Tanzi, director of the Genetics and Aging Research Unit at Massachusetts General Hospital, the accumulation of amyloid beta in the brain can disrupt our sleep patterns, especially as we get older. This lack of slow wave sleep prevents the clearance of amyloid, resulting in a vicious cycle of Alzheimer's disease. Therefore, the development of safe drugs that reduce the production of amyloid is crucial.
Prioritize getting good sleep, as it is crucial for various aspects of health and may also offer brain protection as we age. Those facing sleep issues can consult their doctor to explore customized solutions.
If deep sleep is indeed found to be a confirmed adjustable risk factor for Alzheimer's and dementia, it becomes crucial to provide individuals with the means to closely monitor and track their sleep, according to Isaacson. To achieve this, he suggests utilizing tracking devices capable of monitoring the duration of time spent in bed, actual sleep time, and specific sleep stages.
These devices arent perfect, he cautioned, but "they can at least give people at risk, and their physicians, real-time information that can be acted upon."
Young Asian woman feeling sick and suffering from a headache, lying on bed and taking a rest at home
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According to a study, having a short duration of sleep cancels out the advantages of exercise for the brain. Additionally, incorporating a few positive habits, which could be monitored by tracking devices, may also contribute to safeguarding your sleep and brain health.
Regular exercise helps to loosen up disease-causing proteins known as amyloid in brain cells, while sufficient deep sleep is crucial for removing these harmful proteins from the brain, according to Isaacson.
To enhance sleep quality, it is recommended to restrict alcohol and caffeine intake before bedtime and aim for seven to nine hours of consistent sleep duration each night.
CNNs Sandee LaMotte contributed to this report.
