Consistency Matters: How Changing Sleep Schedules Can Impact Cognitive Function
You’ve probably heard that getting 7 to 9 hours per night is important. Getting enough sleep is essential for maintaining the proper functioning of all your body systems, including the brain.
But consistency in sleep patterns might be as crucial for brain health as the amount of sleep you get.
That’s according to a recent study from the Veterans Affairs VISN-20 Mental Illness Research Education and Clinical Center (MIRECC). This groundbreaking study was the first to link changes in sleep duration with cognitive decline in older adults.
It’s important to note that dementia isn’t a single disease. It’s a term used to describe various conditions affecting memory, thinking, mood, and behavior. The most common type is Alzheimer’s disease (AD).
Changes in the brain of someone with AD start long before the first symptoms appear. Beta-amyloid, a protein fragment formed from the breakdown of a larger protein called amyloid precursor, clumps together and forms plaques between neurons.
Tau, a protein that stabilizes microtubules (essential for neuron structure), also undergoes changes. It detaches from microtubules and sticks to other tau molecules, forming aggregates or tangles inside nerve cells. These changes disrupt neuronal function and communication, leading to cognitive decline and other symptoms associated with the disease.
Another potential early sign of dementia could be alterations in sleep patterns. Sleep problems are common among those with dementia. Estimates say that around 60% to 90% of people afflicted with dementia also face sleep issues.
The connection between sleep and dementia works in both ways. In individuals with dementia, damage to brain cells in areas that control sleep causes sleep disturbances. And in the other direction, sleeping fewer hours than recommended raises the risk of cognitive decline in older adults. Moreover, poor sleep quality can make dementia symptoms worse.
We know that sleep problems can affect cognition. But until now, it wasn’t clear how changes in sleep duration over time influence cognitive function. This study helps to fill that gap.
How Sleep Patterns Predict Cognitive Decline
The scientists in this study looked at data from a large study that started in 1956 and continued until 2020. They focused on older adults who answered questions about their sleep habits and completed tests to check their memory and thinking skills.
Participants in this study were asked how many hours they typically slept each night in the past week. They had to choose from options ranging from less than five hours to more than nine hours per night. They answered this question multiple times between 1993 and 2012.
The researchers used this information to calculate the participants’ sleep duration. This approach also allowed researchers to track how self-reported sleep duration changed over the years. They then grouped individuals into categories based on their sleep duration: short sleep (less than seven hours), medium sleep (seven hours), and long sleep (more than seven hours).
Cognitive impairment was evaluated using tests designed to assess cognitive function. Participants took these tests several times between 1997 and 2019. Those who scored below a specific cutoff point were identified as having cognitive impairment.
The aim was to establish a link between changes in sleep duration and changes in cognitive function with age. As people got older, there was an increasing percentage of long sleepers and fewer short and medium sleepers.
Only a small percentage of participants experienced significant changes in sleep duration over time. Interestingly, when looking at individual data points, researchers saw more noticeable fluctuations in sleep duration than consistent increases or decreases. So, they measured how much sleep duration changed across different study visits. They found that sleep patterns became more consistent as people got older.
In the end, the researchers examined different things like how long people slept, their personal traits, and their genes to see how they related to cognitive function. Basically, they found that those who slept less and had irregular sleep patterns were more likely to see their cognitive abilities decline as they aged.
Basically, they found that those who slept less and had irregular sleep patterns were more likely to see their cognitive abilities decline as they aged.
Sticking to a Consistent Sleep Schedule
The National Sleep Foundation recently published a consensus regarding sleep regularity. Experts agree that maintaining a consistent sleep routine is essential for physical and mental health. But how do you make it happen?
To maintain consistent sleep, start by tweaking your sleep habits. A healthy sleep routine helps your body easily adapt to regular sleep. Here are a few things to try:
- Pick a bedtime and wake-up time and stick to it. Follow this schedule every day, even on weekends (if possible).
- Establish a consistent sleep routine. This may include dimming the lights, taking a warm bath, and reading a book. Follow the same steps daily, and your body will more easily understand that it’s time to sleep.
- Expose yourself to sunlight during the day. This helps your internal clock synchronize with the external environment. This helps your body understand when to sleep and wake up.
- Limit screen time at night. The blue light these devices emit can interfere with the production of melatonin, a hormone that helps you feel sleepy.
- Stay active with regular exercise.
- Avoid caffeine, alcohol, and heavy meals late at night as they can mess with your sleep.
If you’re still having trouble getting enough sleep or maintaining a consistent routine, it’s a good idea to speak with your healthcare provider.
It seems that getting enough sleep isn’t the only thing that matters; sticking to a healthy sleep routine over time is also important. Maintaining a sleep schedule might be key to protecting the brain against diseases like dementia.
