Study Uncovers Link Between Deep Sleep Decline and Dementia Risk

Deep Sleep Decline and Dementia Risk. A recent research study has reveal a potential connection between diminishing deep, slow-wave sleep and an increase risk of developing dementia in later life.

According to the study’s senior author, Matthew P. Pase, who is associate with Monash University, the research findings indicate that the aging process is associate with a decline in the amount of deep, slow-wave sleep, which plays a crucial role in brain health by assisting in the removal of unwant materials from the brain, including beta-amyloid proteins, a hallmark of Alzheimer’s disease.

Understanding Long-Term Deep Sleep Decline and Dementia Risk

The primary objective of this study was to investigate whether persistent reductions in slow-wave sleep over an extend period are link to the risk of dementia and whether dementia-relate processes may contribute to a reduction in deep sleep. The results suggest that chronic decreases in slow-wave sleep, rather than the state of sleep at a specific point in time, are more critical in predicting the risk of dementia.

Key Details from the Research

This research involved 346 participants, with an average age of 69, who underwent two overnight sleep studies conducted between 1995 and 2001. At the end of the study, 52 participants had received dementia diagnoses. The study found that for every percentage decrease in slow-wave sleep per year, there was a 27% increased risk of developing dementia and a 32% heightened risk of dementia related to Alzheimer’s disease. The decline in deep sleep increased from the age of 60, peaked between the ages of 75 and 80, and then gradually decelerated.

Contributing Factors to Consider

Additionally, the study identified other factors that may contribute to the risk of dementia, such as the presence of cardiovascular disease, the use of medications that affect sleep, and carrying a specific gene known to be associated with a higher risk of Alzheimer’s (APOE ε4 allele).

Implications for Sleep Quality and Brain Health

While this research does not conclusively establish a direct cause-and-effect relationship between deep sleep and dementia, it underscores the intricate relationship between sleep quality and the risk of developing dementia. The study highlights the potential existence of a “vicious cycle” in which dementia-related processes in the brain may disrupt sleep patterns, and vice versa.

Expert Recommendations

Experts recommend focusing on closely monitoring and improving sleep quality. Dr. Rudolph Tanzi, from Massachusetts General Hospital, emphasized the importance of developing drugs aimed at reducing amyloid production in the brain, a key factor in the development of Alzheimer’s disease.

To promote improved sleep quality, individuals should adhere to a consistent sleep schedule, reduce their consumption of alcohol and caffeine before bedtime, engage in regular exercise, and utilize sleep tracking devices to monitor their sleep patterns and promptly identify potential sleep-related issues.


Although this study does not definitively establish a direct link between slow-wave sleep and dementia, it highlights the significant role of sleep quality in brain health. Prioritizing high-quality sleep, monitoring sleep patterns, and adopting healthy sleep habits may play a pivotal role in reducing the risk of dementia and cognitive decline in later life.