If You Sleep in This Position, You Might Have Better Brain Health, Says Research

 Your competent? doctor informed you of this years ago, right? Oh NO, you DON'T have a functioning stroke doctor, do you? And your doctor warned you of side sleeping also, right?

• side sleeping (10 posts to February 2017)

JFK Johnson Rehabilitation suggests that side sleeping may increase risk of stroke

The latest here:

If You Sleep in This Position, You Might Have Better Brain Health, Says Research

Discover how your brain "cleans" itself at night, and why researchers say sleeping a certain way could play a role.

Certified neurology nurse Kiara DeWitt, RN, didn’t initially set out to overhaul how she sleeps. But after digging into medical studies on how the brain clears waste overnight, she made one small shift: She started sleeping in a different position.

That change was inspired by a growing body of research on the brain’s glymphatic system, a network that helps clear metabolic waste during sleep. Some early findings suggest that body position may support that process, though experts say it’s far from the most important factor and won’t make up for certain sleep habits.

Ahead, learn more about the sleep position that may give your brain a boost, along with other tips for better rest.

How sleep “cleans” your brain

Sleep isn’t just about giving your body a break; it’s actually when your brain does some of its most important maintenance work. Over the past decade, researchers have come to this conclusion by identifying what’s known as the glymphatic system. At its core, this system works like a cleanup crew during deep sleep, clearing out brain waste that builds up from normal activity.

“When your neurons fire throughout the day, creating thoughts, memories, or decisions, they create metabolic waste,” DeWitt explains. This debris can include amyloid-beta and tau, proteins strongly linked to Alzheimer’s disease when they build up over time.

During waking hours, the glymphatic system remains relatively quiet, explains Jordan Weiss, PhD, assistant professor in the Division of Precision Medicine and Optimal Aging Institute at New York University Grossman School of Medicine. But during deep sleep, its activity ramps up, flushing waste out.

The discovery of this “brain waste garbage disposal system,” as DeWitt calls it, was confirmed in a 2024 human imaging study published in Procedings of the National Academy of Sciences of the United States of America, thus reshaping how experts think about sleep and brain health.

As Dr. Weiss puts it, “The clinical implications are significant.” Not getting enough sleep is one of the most consistent risk factors for Alzheimer’s, and even a single night of poor sleep can raise levels of amyloid-beta in the brain. What we’ve learned about the glymphatic system helps further explain why sleep is so critical for brain health.

What matters most for protecting your brain

The discovery of the glymphatic system in humans was monumental. DeWitt says, “Instead of working off mouse models, we can start to learn about how this applies to dementia, concussion, and cognitive aging throughout life.”

While sleeping in a particular position may give your waste-clearing system a boost, it’s far from the most important factor.

“Sleep quality is leagues ahead of sleep position in nearly every situation I can think of,” DeWitt says. That’s because deep, slow-wave sleep is what best supports the glymphatic system—no matter what position your body is in. “I like to think of it as layers,” adds Dewitt. “How much you sleep is priority. How well you sleep is second. Once you’ve got those first two things down, maybe you can start worrying about position.”

So when it comes to sleep for brain health, here’s what science says you should prioritize before sleep position:

1. Get seven to nine hours of sleep per night: Research suggests that brain waste builds up with sleep restriction. Plus, sticking with regular sleep and wake times better supports your body’s circadian and hormonal rhythms.

2. Treat sleep apnea: If you snore heavily or consistently wake unrefreshed, it’s a sign that you should probably be screened for sleep apnea. Untreated sleep apnea is strongly linked to disrupted waste clearance and cognitive decline.

3. Preserve your deep sleep: Alcohol, sedating medications, and inconsistent schedules can all interfere with deep sleep.

The position that helps your brain the most

So, if you’re already sleeping long, regularly, and well—what position is most likely to help your brain recover? Early data points to sleeping on your side.

The idea that side sleeping could support the brain’s waste-clearing system comes largely from a 2015 animal study published in The Journal of Neuroscience. “MRI scans of rodents showed superior waste removal, including of amyloid-beta proteins, across all observations of the mice sleeping in the lateral position,” DeWitt says.

The likely explanation is biomechanical: Sleeping on your side may allow for more efficient drainage of the brain’s “sink,” helping wash away metabolic waste.

However, as with most animal-based studies, translating these findings to humans requires caution, Dr. Weiss emphasizes. The animals were anesthetized—not naturally sleeping—and rodent brain anatomy differs from our own.

Still, the finding is biologically plausible, Dr. Weiss adds. Some MRI research suggests that body position can influence how waste-clearing fluid moves through the brain, and habitual back sleeping is associated with sleep apnea, “which itself is a significant disruptor of glymphatic function,” he says.

DeWitt says there’s also evidence that side sleeping—particularly on your left side—may offer other benefits, like reducing heartburn and supporting spinal health.

“Of course, we still need to conduct large-scale research with humans and MRI monitoring over years to determine if glymphatic flow is impacted by sleep position and what the magnitude of that effect is,” she explains. “But it’s not really a far-fetched idea.”

And because it’s a safe, no-cost adjustment, it may be worth trying. “Personally, I’ve been feeling better when I sleep on my side,” says DeWitt.

How to start sleeping on your side

If you’re curious about side sleeping, DeWitt recommends trying a body pillow. “Placing a pillow between my knees when sleeping on my side helped alleviate some pressure in my hips and lower back while I got used to it,” she says. “A slightly firmer mattress may help support your shoulders and spine as well.”

But keep in mind that if you’re not comfortable, forcing yourself to sleep on your side could be more trouble than it’s worth.

After all, sleep position is one potential piece of the puzzle, not the foundation. “Protecting your seven to nine hours, getting screened for apnea, and going to bed at the same time each night will do more for your brain than any adjustment to how you position yourself on the mattress,” Dr. Weiss says.

About the experts Kiara DeWitt, RN, CPN, is a certified neurology nurse, the lead educator of neurology and neuroscience at Cook Children’s Medical Center in Fort Worth, Texas, and the head of clinical operations at Medical Director Co. Jordan Weiss, PhD, is an assistant professor in the Division of Precision Medicine and Optimal Aging Institute at NYU Grossman School of Medicine and a former research scientist at the Stanford Center on Longevity.

Science: If You Do This When You Pass Gas, It Could Actually Be Good for Your Brain

 Didn't your competent? doctor have you smelling your own farts or buying them on eBay years ago? Those ruffians around the campfire in 'Blazing Saddles' really improved their intellect.

Do you prefer your doctor, hospital and board of director's incompetence NOT KNOWING? OR NOT DOING? Your choice; let them be incompetent or demand action! You do know incompetent doctors and hospitals can be fired!

• hydrogen sulfide (16 posts to September 2012)

Science: If You Do This When You Pass Gas, It Could Actually Be Good for Your Brain

The 50% demonstrated improvement related to Alzheimer's research may be evidence of how weirdly wonderful nature really can be.

It’s…not a pleasant thought, but maybe it’s a little like the recent research that suggested 90% of us pick our noses in private: If you sniff your stinkers for curiosity or health clues, you’re almost certainly in fair company. Now, research even suggests that when that whiff hits your brain, there could be some protective benefit.

Let’s start with a little science lesson: National experts have said the smelly molecule the body produces is hydrogen sulfide—2024 insight from the Agency for Toxic Substances and Disease Registry stated: “Bacteria found in your mouth and digestive tract produce hydrogen sulfide during the digestion of food containing vegetable or animal proteins.” The agency added that “very high levels can result in sudden unconsciousness or death”—which sounds a little like what your sibling would have cried out in childhood.

In that case, you could get the last laugh. An October 2025 scientific review published in the journal Neuroscience described this gas as a “silent neuroprotector,” citing evidence that it may help counter several key processes involved in Alzheimer’s disease, including inflammation, oxidative stress, and protein damage in brain cells.

That builds on earlier findings. In 2014, pharmacology research noted the gas plays a role in cell communication and blood flow. Then, a 2021 study at Johns Hopkins Medicine published in Proceedings of the National Academies of Science found that hydrogen sulfide may help slow or even reverse cognitive decline engineered to mimic Alzheimer’s disease in mice.

Researchers injected the genetically engineered mice with a hydrogen sulfide-carrying compound called NaGYY. The compound slowly released passenger hydrogen sulfide molecules while it traveled throughout the body. From there, the researchers tested the mice for any changes in their memory and motor function over 12 weeks.

According to a news release, the hydrogen sulfide improved cognitive and motor function by 50% compared to the mice that were not injected with the NaGYY compound. The treated mice were able to “better remember the locations of platform exits and appeared more physically active” than the untreated mice.

According to the researchers, these results showed that “the behavioral outcomes of Alzheimer’s disease” may be reversed by introducing hydrogen sulfide. Hydrogen sulfide appeared to interfere with a damaging chain reaction involving an enzyme called GSK3β and a protein known as tau. In Alzheimer’s disease, tau proteins become abnormally modified and clump together inside neurons, disrupting communication between brain cells. Hydrogen sulfide helped prevent this excessive tau modification, preserving healthier brain signaling.

“Our new data firmly link aging, neurodegeneration, and cell signaling using hydrogen sulfide and other gaseous molecules within the cell,” commented Bindu Paul, M.Sc., Ph.D., faculty research instructor in neuroscience in the Solomon H. Snyder Department of Neuroscience at the Johns Hopkins University School of Medicine.

The growing discoveries may serve as evidence that even for the most seemingly undesirable bodily functions, nature has a purposeful design.

For daily wellness updates, subscribe to The Healthy newsletter and follow The Healthy on Facebook and Instagram. Keep reading:

This 10-Minute, No-Equipment Workout Could Improve Balance and Agility

 Is this better than any balance protocols you got from your doctor? Didn't get any, did you?

This 10-Minute, No-Equipment Workout Could Improve Balance and Agility

New research suggests this 10-minute floor workout can help improve balance and agility.

Balance is super important as you age, considering how falls are the top cause of injury in adults 65 and older.

While the research focused on young adults, the routine itself is easy and beginner-friendly, so older and sedentary people may also benefit from it.

Aging comfortably doesn’t happen by accident, and it requires some solid prep work on your end to ensure you’ll be as mobile as you can be as you get older. A growing body of research suggests that focusing on strength, balance, and agility can help support your body as you age. And now, new research suggests there’s a specific workout to help you do just that—and it can be done in 10 minutes.

The workout is detailed in a new study published in PLOS One. It’s low-intensity and is done lying down (in what’s called the “supine position”). Researchers found modest improvements in balance, agility, and flexibility.

“I am now 81 years old. I do this exercise every morning,” says Yoriko Atomi, PhD, study co-author and professor emeritus at The University of Tokyo. “Prevention is key when it comes to avoiding falls and joint conditions such as knee and lower back pain.” 

Here’s more about the workout, plus why experts say it’s worth your time.

What did the study find?

 The study was divided into two parts. For the first part, a randomized crossover trial, 17 healthy young men were asked to do a 10-minute session of this workout each day for two weeks, along with a control workout. During that time, the researchers assessed their flexibility, agility, strength, and balance.

Another portion of the study involved 22 men and women who did the program for two weeks. During that time, the researchers analyzed their balance by using motion sensors placed on their bodies during a side-step agility test.

Researchers found that when people did the 10-minute program, they had noticeable improvements in their balance, flexibility, and agility. Specifically, they found that these participants didn’t sway as much during standing tests after the workout, had faster side-to-side movements, and did better on a seated forward bend test, suggesting they developed a greater range of motion.

Worth noting: The researchers didn’t find a change in strength or power from this workout. (Grip strength, jumping distance, and sprint speed didn’t change.)

How do you do this workout?

There are a few segments to do this routine. The first focuses on your abdominal muscles. While lying on your back, flex your knees, place your hands on your abdomen, and lightly push into your abs with your fingertips. Flex your abs to push back into your fingertips, and then relax. (The study includes an illustration to show where your fingers should be.) Do this three times.

The next exercise has you lie on the ground, flex your knees, and place your hands on your abdomen. Tilt your pelvis back while keeping your abs contracted. Contract for five seconds with your hips slightly off the floor, then relax, repeating this 10 times.

For the final exercise, lie on your back with both legs straight. Keep the soles of your feet flat on the floor and bend one knee, bringing it as close to your body as possible. Lift the toes of the foot of your bent leg and curl them under. Hold this position and slide your heel along the floor to straighten your leg. When your leg is straight, your foot should be angled up toward your leg. Then, do different “rock, paper, scissors” training with your toes. The “rock” is clenching your toes, “scissors” is raising your big toe, and “paper” is keeping your toes apart. Do this five times.

“These exercises are relatively accessible and low-load, so many people may be able to do them at home,” says Tomoaki Atomi, PT, PhD, study co-author, physical therapist, and researcher at Kyorin University. “However, proper technique matters—especially trunk muscle activation, lower limb coordination, and toe/ankle movement.”

Why is this so helpful for healthy aging?

Balance and agility are helpful at any age, but they’re especially crucial as you get older, explains Molly Gearin, PT, DPT, physical therapist at WAVE Physical Therapy & Pilates. “Falls are the leading cause of injury in adults age 65 and older,” she says. “We also know that an individual’s risk of falls increases with poor balance, agility, and trunk control/flexibility, since the body cannot stabilize itself against external stimuli, such as catching a foot on a curb or being bumped by a dog.”

As a result, doing exercises to work on your ability and balance can lower the risk of falls, along with your overall risk of injury, Gearin says.

One more—very important—thing to point out: Research links good balance and agility to a longer life.

Who benefits the most from this?

This particular study focused on healthy young adults, so it’s hard to say for sure that the perks extend beyond that group. “However, because the program is low-load and relatively safe, it may be especially promising for beginners, older adults, sedentary individuals, or people in rehabilitation,” Tomoaki Atomi says.

Gearin also adds that this is likely to be beneficial for everyone. “Anyone can benefit from a program like this, as it aims to improve the connection between trunk stability and lower body coordination, which are both essential for everyday movement and function she says. “However, because muscle mass and neuromotor control naturally decline with age and sedentary behavior, this type of program may be especially beneficial for older adults, those beginning a wellness journey, or individuals returning from a period of relative inactivity.”

If you’re interested in trying this, Yoriko Atomi recommends incorporating the workout into your day. “Treat this as a daily routine, just like brushing your teeth every morning,” she says.

New Research Found This Headache Symptom Could Indicate a Faster-Aging Brain

 You already have 5 lost years of brain cognition due to your stroke so have your competent? doctor prevent these headaches! My migraines stopped when I quit being a manager.

New Research Found This Headache Symptom Could Indicate a Faster-Aging Brain

Neurologists and neuroscientists are studying an issue affecting an estimated 40 million Americans to help better gauge dementia risk.

If you’re one of the approximately 40 million Americans who experience migraines, as estimated by the American Migraine Foundation, then you’re quite aware a migraine is far more than a “regular” headache. With pain so severe that nausea can co-occur, sensitivity to light and sound, brain fog that lingers even between attacks…all these symptoms can make you wonder whether something deeper is going on in the brain.

Now, a new study brings insight to that question. A team of neurologists and neuroscientists in Taiwan has found that some migraine sufferers show signs of accelerated brain aging. High-tech magnetic resonance imaging (MRI) showed that collectively their brains appear, on average, more than four years older than those of people without the condition. This isn’t cause to panic if this speaks to you—but it may show the importance of finding support to get treatment.

The study, published in March 2026 in the journal Brain Communications, comes from a team of neurologists and neuroscientists in Taiwan who used advanced MRI imaging to compare the brain ages of 110 migraine patients against 70 healthy controls, ranging in age from 20 to 60 years. None of the migraine patients had received preventive treatment for at least three months before the study, meaning the results reflect the brain’s natural response to living with the condition without the effects of medication.

Using a brain-age prediction model trained on data from more than 1,300 healthy individuals, the researchers calculated each participant’s “brain-age gap”—the difference between how old their brain appeared on imaging and how old they actually were.

The migraine patients showed a global brain-age gap of 4.24 years beyond their chronological age. In plain terms: a 40-year-old with migraine had a brain that looked more like that of a 44-year-old without the condition.

When the researchers looked region-by-region across 442 distinct areas of the brain, they found accelerated aging patterns in 66 of them. The affected regions included the prefrontal cortex, which governs decision-making and emotional regulation; the cingulate cortex, involved in pain processing; the parietal and temporal cortices, which handle sensory integration and memory; and the amygdala, the brain’s emotional processing center.

This maps closely onto what migraine patients frequently report in clinical settings: difficulty concentrating, word-finding trouble, emotional sensitivity, and a heightened response to sound.

There were some nuances in the research: For example, not all migraine patients showed the same degrees of brain aging. The study found a meaningful difference between episodic migraine, defined as fewer than 15 headache days per month, and chronic migraine, defined as 15 or more headache days per month for at least three months. Patients with chronic migraine showed higher brain-age gaps than both healthy controls and those with episodic migraine. Patients with episodic migraine, by contrast, did not show a statistically significant difference from healthy controls at the global level, though regional differences may still exist.

The researchers also found that brain aging patterns were associated with a combination of clinical factors: headache frequency, how often patients used painkillers, and scores on a depression-screening measure. No single factor drove the association on its own. It was the cumulative burden of these overlapping challenges that appeared strongest linked to accelerated aging.

The researchers are careful about what conclusions can be drawn. This was a cross-sectional study, meaning it captured a snapshot in time rather than followed patients over years—so it cannot establish whether migraine causes brain aging, whether a predisposition to faster brain aging makes migraine more likely, or whether both share a common underlying cause. The study population was also Taiwanese, which may limit how broadly the findings apply to other groups.

Importantly, the four-year brain-age gap is a group-level finding. It describes a pattern across populations, not a diagnosis for any individual. A migraine patient who gets an MRI will not receive a readout saying their brain is four years older than it should be.

What the findings do suggest is that migraine, particularly in its chronic form, carries long-term implications for brain health that deserve serious attention. The brain regions showing accelerated aging in this study overlap significantly with those implicated in early Alzheimer’s disease and other forms of cognitive decline. It’s possible that research could go on to demonstrate that effective migraine treatment could serve as a form of brain health protection over time.

The authors note that whether preventive migraine medications can slow or reverse these aging patterns is an important open question that future research could help address.

For now, if you live with frequent migraines and have been wondering whether to pursue preventive treatment, this research offers one more reason to have that conversation with your doctor.

For daily wellness updates, subscribe to The Healthy newsletter and follow The Healthy on Facebook and Instagram. Keep reading:

• We Asked 7 Experts the Secret to Keep the Brain Young—and They All Said the Same Thing
• If You Sleep in This Position, You Might Have Better Brain Health, Says Research
• Following This Popular Diet Improved Brain Health in 70% of People, Says Pilot Study
• Science: If You Do This When You Pass Gas, It Could Actually Be Good for Your Brain

Thrombectomy Boosts Functional Independence in Medium-Vessel Strokes, finds study

 Failure to get to 100% recovery IS STILL A FUCKING FAILURE! Don't use your tyranny of low expectations to declare this a success!

Thrombectomy Boosts Functional Independence in Medium-Vessel Strokes, finds study

New Review Examines Whether Supplements Can Help Slow Parkinson's Disease Progression

 With your risk of Parkinsons post stroke your competent? doctor needs to be an expert in this! Is s/he? NO? So, incompetence prevailed or maybe just laziness, regardless you are the victim. 

Parkinson’s Disease May Have Link to Stroke March 2017 

New Review Examines Whether Supplements Can Help Slow Parkinson's Disease Progression

This Dark Chocolate Compound Is Linked To Slower Biological Aging, Study Finds by mindbodygreen

 Will your competent? doctor get the dietician to add this to your hospital and discharge diet protocols? Oh, sorry; nothing will occur because incompetence will prevail!

Your competent? doctor already knew about theobromine and has a protocol on it already, right? Oh No, NOTHING?

• theobromine (8 posts to August 2016)

Ask your fuckingly incompetent? doctor and hospital to do the research that answers EXACTLY HOW MUCH TO CONSUME! Oh, they are SO INCOMPETENT they can't even manage that simple task?

This Dark Chocolate Compound Is Linked To Slower Biological Aging, Study Finds

ISMRM: MRI-based AI predicts organ aging before disease signs emerge

 If you really want to get into the minutiae of your aging. I'm not worried about my aging, I'll just get there. 

ISMRM: MRI-based AI predicts organ aging before disease signs emerge

A deep-learning model combining MRI scans with blood markers, imaging-derived biomarkers, and lifestyle data successfully predicted organ-specific biological age, according to poster data presented May 14 at the International Society of Magnetic Resonance in Medicine (ISMRM) meeting.

The model also identified accelerated aging in participants who went on to develop Alzheimer's disease and myocardial infarction, wrote a team led by Veronika Ecker of the University Hospital of Tuebingen in Germany.

"Biological age has the potential to capture the combined effects of genetic, lifestyle, and health-related factors on both individual- and organ-specific aging, but remains difficult to quantify," Ecker and colleagues noted. "Integration of MRI with other health-related data may improve estimation and provide insights into early disease risks."

MRI offers detailed information on both structure and function of the human body, capturing patterns that reflect individual differences in the aging process, the group explained, writing that "these patterns allow estimation of biological age which may diverge from chronological age due to genetic, environmental, and lifestyle factors."

The investigators developed a deep-learning model that combined 3D MPRAGE brain MRI and 2D+t cardiac cine MRI results with imaging-derived biomarkers, blood-based measures, and lifestyle information and applied it to 70,000 UK Biobank participants between the ages of 44 and 83 in an effort to predict biological age of the brain and heart and to identify accelerated aging. Because no ground truth for biological age exists, the model was also trained on a subcohort of healthy individuals in which biological and chronological age were assumed to approximate one another, the group explained.

Overall, Ecker and colleagues reported that the model detected a mean brain age gap of 1.98 years and a heart age gap of 0.81 years in disease subgroups compared with healthy controls – a result which suggests that it captures pathological aging processes before clinical diagnosis, they noted.

Predicted age gaps (= predicted age - chronological age) of the brain and heart across chronological age for a healthy test set (blue, upper row) and in comparison with a diseased subcohort (orange, lower row). Diseased subgroups are defined per organ (brain: patients developing Alzheimer's disease; heart: patients developing myocardial infarction).Veronika Ecker and ISMRM

"Integrating … complementary data sources can strengthen the robustness and interpretability of biological age prediction," the team wrote, concluding that "the model revealed consistent age-related embeddings, outperformed single-modality approaches, and captured accelerated aging in participants at higher disease risk."

These Trials Will Extend Your Healthspan by Super Age

 Have your competent? doctor prepare protocols for these so you can increase your healthspan.

These Trials Will Extend Your Healthspan

Electromagnetic Stimulation for Longevity: What the Science Says by Super Age

 What does your competent? doctor have to say about this?

Was anything done with this? Not doing anything changes competence to incompetence, it's as simple as that!

• magnetic stimulation (7 posts to October 2016)

Electromagnetic Stimulation for Longevity: What the Science Says

The Trainable System We Overlook When We Talk About Balance(Inner ear) by Super Age

 What is your doctors' EXACT PROTOCOL to train your inner ear for balance recovery? Oh No, NOTHING!  

Let's check how long incompetence has existed!

• balance recovery (43 posts to january 2016)
• balance (176 posts to November 2011)
• balance training (9 posts to May 2021)

The Trainable System We Overlook When We Talk About Balance

Low-Level Air Pollution Linked to Cognitive Decline, Brain Damage

 Have your competent? doctor recommend EXACTLY how to test for this and EXACT INTERVENTIONS that prevent the problem! And why can't your incompetent? doctor do that simple task? You do expect your doctor to bring back your  5 lost years of brain cognition due to your stroke and not make it even worse, right?

Low-Level Air Pollution Linked to Cognitive Decline, Brain Damage

Summary: A new study reveals that long-term exposure to everyday air pollution is directly linked to poorer cognitive function and visible brain damage. Conducted as part of the Canadian Alliance for Healthy Hearts and Minds (CAHHM) study, researchers analyzed nearly 7,000 middle-aged adults across five Canadian provinces.

Remarkably, the findings demonstrate that even low levels of fine particulate matter and nitrogen dioxide, well within international “clean air” standards, are associated with reduced scores in memory, comprehension, and mental processing speed, with women showing heightened vulnerability to visible structural brain damage on MRI scans.

Key Facts

• The Low-Exposure Threshold: Unlike previous research targeting heavily polluted global regions, this study proves that cognitive damage occurs even in Canada, a country with some of the lowest average air pollution levels in the world.
• Direct Biological Impact: The negative relationship between air quality and brain health persisted even after researchers adjusted for major cardiovascular risk factors like high blood pressure, diabetes, and body adiposity, suggesting pollution directly targets the central nervous system.
• Gender-Specific Vulnerability: Higher exposure to traffic-related air pollution was linked to visible, structural signs of damage on brain MRI scans, a trend that was uniquely more pronounced in female participants.
• Targeted Environmental Pollutants: The study tracked multi-year exposure to two common byproducts of vehicle exhaust, industrial emissions, and wildfire smoke: nitrogen dioxide and fine particulate matter.

Source: McMaster University

The air pollution we breathe daily could be harming more than just our lungs and hearts. New research from McMaster University suggests that fine particles from traffic, industry and wildfire smoke is linked to worse cognitive function.

The study, published online in the journal Stroke on May 13, 2026, found that people living in areas with higher air pollution scored worse on tests of memory, understanding and mental speed. This finding was true for places where air pollution is considered low by international standards.

Higher levels of traffic-related pollution were also linked to small but visible signs of damage to the brain seen on MRI scans, and more so in women.

These relationships remained even after accounting for heart-health risk factors like high blood pressure, diabetes, and body adiposity, suggesting that air pollution may be directly affecting the brain.

“Dementia doesn’t happen overnight,” says Russell de Souza, associate professor with McMaster’s Department of Health Research Methods, Evidence, and Impact and the study’s corresponding author.

“It develops over decades. Identifying factors that may damage the brain early, and that are potentially preventable, is critical for protecting brain health later in life.”

While the study doesn’t prove air pollution causes dementia, it does add to a growing body of evidence that air quality may impact age-related changes in memory or thinking.

Unlike many previous studies conducted in regions with heavy pollution, this research focused on Canada, a country with some of the lowest average air pollution levels in the world. Researchers studied nearly 7,000 middle-aged adults across five Canadian provinces to see if long-term exposure to common air pollutants was linked to how well people think and remember.

To do this, researchers compared people’s exposure over several years with their performance on cognitive tests. They focused on two pollutants: fine particles in the air known as fine particulate matter or PM2.5 and nitrogen dioxide. Both are common byproducts of vehicle exhaust, with PM2.5 particles also common within fumes from wildfires and industry.

“Canada’s air is often described as clean, but our findings suggest that even low levels of air pollution are linked to worse brain health,” says lead author Sandi Azab, an assistant professor with McMaster’s Department of Medicine.

“These are changes that can happen quietly, years before any noticeable symptoms appear.”

Researchers say long‑term follow‑up studies are needed to better understand how ongoing exposure to air pollution may influence cognitive decline over time, and whether improving air quality can help protect brain health.

Funding: The research was conducted as part of the Canadian Alliance for Healthy Hearts and Minds (CAHHM) study and was supported by funding from the Canadian Partnership Against Cancer, the Heart and Stroke Foundation of Canada, and the Canadian Institutes of Health Research.

Key Questions Answered:

Q: If I live in a country with “clean air” like Canada, am I completely safe from pollution-related brain damage?

A: According to this study, no. The researchers discovered that even levels of air pollution considered exceptionally low by international standards are quietly linked to worse brain health. The damage happens subtly and incrementally over several years, long before any obvious clinical symptoms ever appear.

Q: Why does the study adjust for things like high blood pressure and diabetes?

A: Cardiovascular issues are already known to impair blood flow to the brain and cause cognitive decline. By statistically removing the influence of blood pressure, diabetes, and body fat, the McMaster team proved that air pollution isn’t just hurting the heart and lungs first, it appears to be directly damaging brain tissue independently.

Q: Does breathing in wildfire smoke or traffic exhaust mean I will get dementia?

A: The study does not definitively prove that air pollution causes dementia, but it provides powerful evidence that air quality directly accelerates age-related changes in memory and thinking. Because dementia develops over decades, identifying and minimizing exposure to these preventable environmental particles early in midlife is a critical step for protecting your brain later.Editorial Notes:

• This article was edited by a Neuroscience News editor.
• Journal paper reviewed in full.
• Additional context added by our staff.

About this pollution and neurology research news

Author: Adam Ward
Source: McMaster University
Contact: Adam Ward – McMaster University
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Association of Air Pollution With Brain Health: A Cross-Sectional Analysis in Adults Living in Canada” by Sandi M. Azab, Sonia S. Anand, Dany Doiron, Karleen M. Schulze, Jeffrey R. Brook, Michael Brauer, Dipika Desai, Matthias G. Friedrich, Shrikant I. Bangdiwala, Vikki Ho, Trevor J.B. Dummer, Paul Poirier, Jean-Claude Tardif, Koon K. Teo, Scott Lear, Perry Hystad, Salim Yusuf, Eric E. Smith, and Russell J. de Souza. Stroke
DOI:10.1161/STROKEAHA.125.054251