- Sufficient sleep is crucial for maintaining mental and physical well-being.
- A new study by Canadian researchers has found that insomnia can lead to an increased risk of memory loss in adults over 45.
- For many people, getting enough sleep can become more difficult as they age due to brain and hormonal changes.
- Lifestyle shifts, therapies, sleep aids, and medication can all help promote quality sleep.
A good night’s rest allows the body and brain to rejuvenate — and new research has indicated just how important sufficient sleep can be for preserving cognitive function.
A Canadian study, recently published in the journal SLEEP, analyzed data from over 26,000 adults ages 45 to 65 that was collected over 3 years.
In 2019, participants completed a sleep and memory questionnaire and underwent neuropsychological testing. The same questioning and testing were then repeated in 2022.
The researchers found that those who had no insomnia symptoms in 2019 but had developed some insomnia symptoms or probable insomnia disorder (PID) by 2022 were more likely to report subjective memory decline. Those with insomnia symptoms in 2019 who had developed into PID by 2022 self-reported greater memory loss concerns.
Memory testing also revealed that men with insomnia disorder performed worse than women with the condition.
“While this does not mean that their memory was actually worse, it does place them at a greater risk for developing memory problems in the future,” Nathan Cross, PhD, a postdoctoral fellow from the Sleep, Cognition and Neuroimaging Laboratory in Montreal and co-lead of the study, explained to Healthline.
While prior research has explored the effects of sleep on cognitive function, Cross said the new study differed in one key aspect.
“A lot of research has either used very focused and detailed methods in small sample sizes or very single-dimension, general measures (e.g., questions like ‘how long do you sleep?’ or ‘how good is your sleep?’) in larger populations,” he said.
“We had access to detailed information on the sleep habits of a large group of Canadian adults. [This] allowed us to group individuals based on the severity of their sleep complaints: Insomnia disorder, insomnia symptoms, or healthy sleepers. This has never been done before.”
Cross highlighted that the study investigated the impacts of insomnia disorder — not just those from a bad night’s sleep.
“Insomnia is a recognized psychological disorder with a set of criteria for diagnosis,” he said.
The criteria for insomnia disorder are
If one or more of the DSM-5 criteria are met and the sleep difficulties are present for at least 3 months, an individual may be diagnosed with insomnia disorder.
A diagnosis, Cross added, “includes a recognition that the sleep problems impact functioning in the daytime.”
In fact, the impact of insomnia on a person’s physical and mental abilities can be significant.
“There is a wealth of literature showing a decline in psychophysiological performance when people are not getting enough sleep,” Brian A. Moore, PhD, assistant professor of psychology at Kennesaw State University and advisor for Momentous, shared with Healthline.
“For example, studies of sleep deprivation in military personnel have found reductions in performance when personnel were getting fewer than 7 hours of sleep a night,” he said.
How sleep impacts the brain
During sleep, Cross explained that the brain is busy “clearing toxic waste that builds up over the day and changing the connections among brain cells to save energy.”
“It is also associated with strengthening memories learned during the day, reinforcing them so that we can extract meaning and links between different experiences,” he added.
Moore said that a lack of sleep also means the body isn’t able to recharge to its fullest, so energy is spread more thinly.
“When our bodies experience prolonged stressors (such as insufficient sleep), other resources must pick up the slack,” he shared. “Our internal resources are not infinite — and when we do not get enough sleep, there is often a degradation in areas of performance like memory or reaction times.”
The Canadian study focused on the sleep of older individuals and noted that many reported worsening sleep patterns over the 3-year research duration.
And for many people, the ability to get quality sleep can start to diminish as they get older.
“We specifically see problems with maintaining sleep in [older adults],” Chelsie Rohrscheib, PhD, neuroscientist and head sleep expert at Wesper, told Healthline.
“The brain’s ability to control and maintain sleep can decline during age. “This is because brain function in general declines as the communicating cells, called neurons, age and become dysfunctional.”
A change in hormones can also impact sleep quality and duration.
“An aging brain may lose the ability to regulate hormones such as melatonin and cortisol, and neurotransmitters such as GABA, that are essential for sleep health,” Rohrscheib noted.
Moore noted that other elements can also play a role in sleep quality as people age.
“There are biological, social, and psychological factors that differentially but dynamically influence cognitive decline,” he said. “It is safe to say that, over time, chronic sleep dysfunction will contribute to downstream health concerns, and that immediate intervention is always best.”
Whether you have insomnia, sleep difficulties, or simply want to get a better night’s rest, there are steps you can take to improve the quality of your sleep.
Practice good sleep hygiene
You might have heard the phrase “sleep hygiene” — and according to Rohrscheib, it’s important to develop a regimen you can stick to.
“Pay close attention to the actions you do during the day and how that might affect sleep later on,” she said. “This includes not consuming caffeine too late in the day, not using electronics before bed, and keeping a strict sleep schedule.”
Try supplements or medication
Sleep aids can be particularly beneficial for promoting sleep, especially among older individuals.
“Studies have shown that seniors produce less melatonin [the sleep hormone] than what is required for sleep,” Rohrscheib explained. “Other prescription medications may also be necessary,” she added.
Either way, always ask your doctor for guidance before taking any new supplement or medication.
Consider other health concerns
Various health conditions can contribute to insomnia symptoms, and addressing these may help improve sleep quality.
Rohrscheib noted that ailments including “chronic pain, arthritis, cardiovascular disease, diabetes, or mental health disorders” — many of which become more prevalent among older adults — can all negatively impact how well you sleep.
Train your body and brain
Experts like Rohrscheib agree that exercise and mental stimulation are important for good sleep quality.
“Seniors should get at least 30 minutes of exercise a day and spend a significant portion of their day on mental activities, such as puzzles or reading,” she said.
Give cognitive therapies a try
Sometimes insomnia symptoms can occur because the mind goes into overdrive worrying about the fact that you aren’t sleeping.
In these instances, relaxation exercises like guided imagery can help to promote sleep.
Sleep has long been associated with cognitive function, and the new research further highlights its potential role in relation to memory loss.
However, explained Moore, it’s worth noting that levels of memory loss in this study were self-reported — and, “in some instances, it may be an ‘expectancy effect’ wherein people anticipate having a poor memory as they age.”
While more clinical research on the link between insomnia and memory loss is still needed, the findings from the Canadian study still offer important lessons.
“The results show it is important to take sleep complaints seriously and talk about them with your doctor,” Cross said.