A new study linking disrupted sleep patterns to changes in brain regions associated with Alzheimer’s disease is renewing attention about the importance of healthy sleep habits.

Research published in the Journal of the Alzheimer’s Association suggests that fragmented circadian rhythms, irregular sleep and wake cycles, may be linked to shrinkage in areas of the brain tied to memory and cognition. While experts caution that the findings are still preliminary, they say the study adds to growing evidence that poor sleep can have serious long-term health consequences.

“So it’s not a direct linkage that says, you know, if you have fragmented sleep, or if you sleep too much during the day, that you’re obviously going to get dementia,” says Bradley Gleason, MD, internal clinical director, OSF Sleep Lab in Peoria, Illinois. “But the linkage is strong enough, and it points to needing more studies and more data down the road that there could be a significant link so obviously it’s very important to clean up your sleep disorders so that the risk of dementia and Alzheimer’s potentially is lowered.”

Researchers have long known that sleep affects multiple systems throughout the body, including cardiovascular health, immune function and mental performance. The latest findings raise concerns that chronic sleep disruption could also contribute to neurodegenerative diseases over time.

Don’t ignore sleep issues

Dr. Gleason says many people still underestimate the importance of sleep, often delaying treatment for sleep disorders such as insomnia or obstructive sleep apnea.

“We have lots of other data about cardiovascular health and high blood pressure and stroke and all that we know is linked to poor quality sleep and not getting enough sleep,” Dr. Gleason shares. “So absolutely, yeah, you want to take this seriously. I’m obviously biased but we want to attack your sleep problems head on as early as we can.”

The growing role of wearable devices such as smart watches and sleep trackers in monitoring sleep habits can be helpful. But Dr. Gleason stresses that while those tools can provide useful information, they are not always reliable enough to replace formal sleep evaluations.

At the study’s conclusion, researchers found that participants with more consistent daily sleep-wake patterns had larger volumes in the memory-associated brain areas – the hippocampus and parahippocampus – and less shrinkage of the amygdala, a region vital to emotional processing.

When sleep is fragmented, the body becomes stressed according to Dr. Gleason.

Bad sleep impacts your immune system

“So, you’re not sleeping well and therefore you’re going to have the immune-related ways your body kind of fixes itself is not happening and so your cells are dying off and that could lead to some of the study results that now you’re getting atrophy in some of those important brain areas. So that’s what I would say ‘I need to try to fix why are you having these troubles so we can address it now.’”

According to Dr. Gleason, future research will be needed to determine whether poor sleep directly contributes to dementia risk or whether early brain changes themselves disrupt sleep. In the meantime, the message is straightforward: addressing sleep problems early may help protect long-term health.

“There is a link potentially between poor quality sleep and potentially long-term bad outcomes, including memory problems and/or Alzheimer’s disease. It just points to the importance of sleep quality now to avoid those problems later.”

Here are some tips for getting good sleep to potentially help brain health as you age:

• Waking up at about the same time every day
• Getting bright light exposure in the morning
• Staying physically active during the day
• Keeping meals and bedtime consistent
• Limiting long or late naps
• Avoiding caffeine or alcohol too close to bedtime

If you are having trouble getting to sleep or staying asleep, start by talking to your primary care provider. They might also refer you to a sleep specialist at an OSF Sleep Clinic.

Dr. Bradley Gleason

B-roll-Poor sleep and brain issues

Getting plenty of sleep is vital - not only for your ability to feel well rested and alert, but also for your health and wellbeing in general. The National Institutes of Health warns a chronic lack of sleep can increase the risk for a myriad of health issues, including stroke, seizures, high blood pressure and heart disease.

For many Americans, however, sleep doesn’t always come easily. In fact, nearly 60 million Americans a year experience insomnia and wake up feeling unrefreshed. For some, getting back into a sleep routine is as easy as counting sheep. For others, it might take a bit of assistance.

Dr. Sarah Zallek is a neurologist who specializes in sleep disorders for OSF HealthCare Sleep. She says sleep disruptions can have countless causes such as personal losses, stress or sadness. The COVID-19 pandemic also impacted sleep for many.

“A huge number of people had sleep disruption during COVID, and a lot of people turned to over the counter medications or other therapies for their sleep during that time,” says Dr. Zallek. “It's not just COVID, though. I think people are more aware of sleep and its disruptions, and there's a lot of marketing out there for products and services to help sleep for better or worse.”

One sleep aid option that is becoming more popular is the use of melatonin supplements. Melatonin is a hormone your brain produces in response to darkness. It helps with the timing of your circadian rhythms and with sleep.

Melatonin can be made synthetically and is most often used as a supplement in this form. According to recent study findings published by the U.S. Centers for Disease Control and Prevention (CDC), its use is becoming more popular; melatonin sales increased 150% between 2016 and 2020.

But does melatonin really work? Dr. Zallek says while melatonin does have some value, finding the reason behind a sleep disruption is the best long term solution.

“The vast majority of us who have sleeping problems aren't going to need melatonin or a prescription sleeping pill or anything else for their sleep because we want to treat the underlying problem. But if you have trouble sleeping, melatonin might be helpful.”

In the U.S., melatonin is sold as a supplement and is not regulated as a drug. This means the U.S. Food and Drug Administration (FDA) doesn’t have oversight over the purity of ingredients or the accuracy of dosage claims. Without that oversight, Dr. Zallek warns that there might be more – or less – than you bargained for in your bottle.

“Manufacturers of something like melatonin can put a lot of different things in the bottle without necessarily being noticed. In old studies I know that they've analyzed some melatonin products and found none, and found a lot more melatonin in other products. One product had valium in it, which will definitely make you go to sleep but is not the goal. So you don't know what's in the bottle and over the counter products are risky for that reason,” she warns.

Adults aren’t alone when it comes to sporadic sleep issues. Kids can suffer from insomnia and other sleep disorders as well, and more and more often, parents are turning to melatonin to help their kids fall – and stay - asleep. Dr. Zallek admits that some pediatricians might recommend melatonin for their patients. She, however, does not, citing concern for the unknowns.

“Melatonin is widely distributed throughout the body. Melatonin is a naturally occurring substance. It's a very normal hormone that we all produce. Some of us have more or less of it, but it helps regulate our internal clock for a lot of things – including sleep – and it has some crosstalk with other hormones. We don't really know what the effect is on children who take it consistently for some time,” explains Dr. Zallek.

Because melatonin is sold as an over the counter supplement similar to vitamins, parents may think it’s safe to leave on a nightstand or within a child’s reach. Dr. Zallek cautions against that. Melatonin is often packaged in kid-enticing forms like gummies, and kids might be tempted to ingest too much without understanding the danger.

In fact, pediatric melatonin ingestions reported to U.S. poison control centers increased 530% from 2012 to 2021. Last year alone, U.S. poison control centers received more than 52,000 calls about children consuming worrisome amounts of the supplement.

“It's incredibly important to keep all medications away from kids, because even an over the counter medication is potentially dangerous,” Dr. Zallek warns. “So everything in the wrong dose is dangerous, and kids are curious creatures and might be very apt to try something that you don't know they're taking.”

Dr. Zallek urges anyone – adults and kids alike – to speak to their doctor before starting a melatonin routine for sleep. While melatonin has not been found to be habit forming, it doesn’t solve the root problem of most sleep issues. There are easy steps you can take to try to curb insomnia without medication. These include:

• Maintaining the purpose of your bed: Use your bed only for sleeping and intimacy. When you get in bed, your brain should know it’s time to go to sleep.
• Following a sleep schedule: Go to bed and wake up at the same time every day.
• Staying active: Activity is an important sleep hygiene step. However, to avoid restlessness, you should schedule this active time a few hours before you plan on going to bed.
• Scheduling meals: Avoid late dinners and late-night snacks, and limit caffeine.

Those with persistent trouble sleeping or sleeplessness should see a provider who specializes in sleep medicine.

Most people with insomnia do not need medication or a sleep test. A sleep specialist can usually help reduce the issues that might be leading to insomnia, or work around them with sleep-promoting strategies.

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