Irregular Sleep – Not Just How Much Sleep You Get – May Impact Your Dementia Risk

Having a consistent sleep schedule can help you more easily fall asleep and be more alert throughout the day. It also comes with health benefits unrelated to sleepiness, like better heart health. A new study finds it may help with brain health, too.

Research recently published in the journal Neurology investigated the link between sleep regularity and dementia risk. The authors say while irregular sleep is associated with an increased risk of cardiometabolic conditions, there isn’t clear evidence for its impact on incident dementia. Other research has linked insufficient sleep with dementia, however.

According to the findings, people who consistently have irregular sleep are more likely to develop dementia, compared with people who have both moderate and higher levels of sleep consistency. This provides more evidence that sleep can impact your dementia risk, even if you’re still getting enough of it each night.

Dr. Matthew Paul Pase, study author from Monash University in Australia, says, “Sleep health recommendations often focus on getting the recommended amount of sleep, which is seven to nine hours a night, but there is less emphasis on maintaining regular sleep schedules. Our findings suggest the regularity of a person’s sleep is an important factor when considering a person’s risk of dementia.”

The research involved data from more than 88,000 participants in the UK Biobank study. Their average age was 62. The team gave each participant a sleep regularity index score based on how likely they were to be asleep or awake at any two time points 24 hours apart, averaged over seven days. This was measured with a wrist device.

After an average follow-up period of seven years, 480 participants had developed dementia.

The researchers found that people in the lowest fifth percentile in the sleep regularity index had an average score of 41, while those in the top 95th percentile averaged a score of 71. All the rest averaged out to 60.

After adjusting for possible contributing factors, those in the lowest percentile had a 53% higher risk of developing dementia than those in the middle group. The research also showed that those with the highest score did not have a lower risk of developing dementia than the middle group, indicating that even moderate sleep consistency may be enough to avoid an increased risk of developing the disease.

Dr. Pase says, “Effective sleep health education combined with behavioral therapies can improve irregular sleep patterns. Based on our findings, people with irregular sleep may only need to improve their sleep regularity to average levels, compared to very high levels, to prevent dementia. Future research is needed to confirm our findings.”

In the meantime, regular sleep does have other demonstrated benefits, so what can you do to keep yours consistent? You can try using bedtime reminders and sticking to a wind down routine that gets you ready for sleep. That can include avoiding screens, opting for a book, meditating, or listening to calming music.