Doing This at Night Slashes Your Alzheimer's Risk, New Study Finds

One habit was found to help keep the brain healthy over time.

When it comes to keeping an eye on our health, things like our daily diet and exercise routine usually come to mind first. But even in the evenings, certain surprising habits can play a big part in staving off serious ailments. And according to a new study, making sure to do one thing each night could drastically reduce your risk of developing Alzheimer's disease. Read on to find out what to prioritize as part of your nocturnal ritual.

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Getting enough sleep each night can help lower your risk of Alzheimer's disease.

A senior couple sleeping in bed

In a study published Feb. 10 in the scientific journal PLOS Genetics, scientists found that getting enough sleep each night actively reduces the likelihood of developing Alzheimer's disease later in life. According to their research, the reason for health boost comes from maintaining healthy sleep habits and avoiding sleep interruptions, which allows the brain to rid itself of the protein Amyloid-Beta 42 (AB42) before it can form clumps in the brain. Such protein clusters are typically viewed as a precursor or warning sign of the onset of Alzheimer's disease.

"Circadian regulation of immune cells plays a role in the intricate relationship between the circadian clock and Alzheimer's disease," Jennifer Hurley, PhD, the study's lead author, an expert in circadian rhythms, and associate professor of biological science at Rensselaer Polytechnic Institute (RPI), said in a statement. "This tells us a healthy sleep pattern might be important to alleviate some of the symptoms in Alzheimer's disease, and this beneficial effect might be imparted by an immune cell type called macrophages/microglia."

Circadian rhythms set different bodily functions in motion that keep you healthy in many ways.

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The study builds upon previous understandings of the importance of circadian rhythm in overall health. According to the researchers, the circadian system uses a core set of "clock proteins" that helps regulate bodily functions that take place either during the day or at night by controlling hormone and enzyme levels in the body. This allows your body to be prepared for different tasks, whether you're asleep or awake.

The natural cycle allows the body to enter a "rhythm" that controls everything from specific immune responses to body temperature during the day and throughout the night. However, when the cycle is interrupted by not getting enough sleep or being woken up constantly at night by health problems such as sleep apnea, it increases the risk of severe health issues such as diabetes, cancer, and Alzheimer's disease.

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Getting enough sleep helps your body clear the brain of harmful proteins related to Alzheimer's disease.


According to the team's research, immune cells known as macrophages, which function to rid the body of unwanted material, help clear harmful AB42 from the brain during a process called phagocytosis. Previous studies conducted by Hurley and her team found that the levels of macrophage RNA and proteins rise and fall along with the body's circadian rhythm. The new study established that such oscillations in certain enzymes helped produce two components of the macrophage cell structure known as heparan sulfate proteoglycan and chondroitin sulfate proteoglycan. Specifically, lower levels of the two proteoglycans make it easier for macrophages to clear the brain of AB42.

The latest experiment tested the changes brought on by the circadian rhythm and how they related to the cell surface structures, discovering that the amount of AB42 that the healthy macrophages can clear follows the same cycle—meaning sleep plays a factor in optimizing the process. By comparison, other immune cells that aren't regulated by the body's internal clock didn't share this pattern.

"What's clear is that this is all timed by the circadian clock," Hurley explains. "When there's a lot of these cell surface proteoglycans, the macrophages don't ingest the AB42. We're not certain why that would be, but there is definitely a relationship. In theory, if we could boost that rhythm, perhaps we could increase the clearance of AB42 and prevent damage to the brain," she concludes.

Other studies have found that getting six or fewer hours of sleep each night could increase your dementia risk.

Closeup of alarm clock with senior woman in deep sleep in background
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While getting enough sleep overall is essential, another study published in April 2021 in the scientific journal Nature Communications found that sleeping six hours a night or less a night was linked to an increased risk of dementia in people between 50 and 60 years old. Researchers from the French health research institute Inserm analyzed data from a long-term study by University College London, which followed 7,959 British individuals between 1985 and 2016. The team then compared the health of adults who didn't get enough sleep to people who slept the recommended seven hours.

Overall, 521 participants developed dementia throughout the study and were diagnosed at an average age of 77. The results found that participants who slept seven hours a night had the fewest cases of dementia. By comparison, there was a 30 percent increase in dementia risk in those who consistently clocked a maximum of six hours a night in their 50s and 60s.

"Many of us have experienced a bad night's sleep and probably know that it can have an impact on our memory and thinking in the short term, but an intriguing question is whether long-term sleep patterns can affect our risk of dementia," Sara Imarisio, PhD, Head of Research at Alzheimer's Research U.K., said in a statement in response to the new study. "We know that the diseases that cause dementia start up to two decades before symptoms like memory loss start to show, so midlife is a crucial time for research into risk factors."

RELATED: 98 Percent of People With Alzheimer's Develop This Symptom First, Study Says.

Zachary Mack
Zach is a freelance writer specializing in beer, wine, food, spirits, and travel. He is based in Manhattan. Read more
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