Smoke Gets In Your Eyes -- Your Lungs and Your Brain

"It's not just a few days in these extreme events that you need to protect  yourself."

"It is also the days when the sky looks OK [while air quality indexes or weather reports warn of the presence of smoke]."

Dr. Kai Chen, associate professor, Yale School of Public Health 

 

The health effects of short-term PM_2.5 exposure, and subsequently smoke, can range from relatively minor (e.g., eye and respiratory tract irritation) to more serious health effects (e.g., exacerbation of asthma and heart failure and premature death). In addition, there is initial evidence that short-term smoke exposure may lead to preterm birth (Picciotto et al. 2024) and impact brain function (i.e., cognitive performance as measured through a brain-training game) (Cleland et al. 2022). Fine particles are respiratory irritants, and exposures to high concentrations can lead to persistent coughing, phlegm, wheezing and difficulty breathing. Exposure to PM_2.5 may affect the body’s ability to remove inhaled foreign materials, such as viruses and bacteria, from the lungs. For example, some studies have reported an increase in the risk of COVID-19 cases and deaths in response to wildfire smoke exposure (Zhou et al. 2021; Meo et al. 2021; Schwarz et al. 2022). Although most healthy people will recover quickly from smoke exposure, some may experience health effects such as pulmonary inflammation and transient reductions in lung function (U.S. EPA 2019).

United States Environment Protection Agency  

Vancouver skyline   Wildfires and smoke have always occurred in British Columbia, but they are becoming more frequent and severe as the climate changes. Wildfire smoke is a form of air pollution that can affect your health.  BC Centre for Disease Control 

 

Evaluation of air pollution from wildfires presents unique challenges, compared to air pollution from other sources, such as traffic or industrial point sources, as smoke exposure is seasonal and episodic in nature (Gould et al., 2023). Also, as the number and size of wildfires impacting an area are variable and as smoke production from wildfires is not constant or steady, the concentration of smoke experienced by populations can vary considerably, and can include high levels of exposure for short time periods or moderate exposure levels lasting for several days or longer. Additionally, to evaluate the health effects of wildfire smoke, it is necessary to distinguish the contribution of wildfire smoke from that of other sources of air pollution within the mixture that people are exposed to. To address this, researchers have employed a variety of methods to assess exposure to wildfire smoke for use in health studies including use of land-based PM monitors, satellite imagery, air quality modelling, comparison of fire versus non-fire periods, proximity to wildfire burn area, and self-reports. In these studies, the most commonly used surrogates for wildfire smoke exposure are PM_2.5 (particles with a diameter of 2.5 micrometres or less) and PM₁₀ (particles with a diameter of 10 micrometres or less). For the primary investigations included in the systematic reviews considered here, the health outcome data were based on administrative sources (for example, mortality registries, health care utilization data), surveys, or self-reports. In addition, most of the primary studies focused on short-term or episodic exposure to wildfire smoke (that is, daily exposure), while some of the studies assessing mental health impacts considered health effects in years following the wildfires, and studies of reproductive or developmental impacts considered wildfire smoke exposure during the gestational period. It is noted that the health effects of PM_2.5, a key pollutant in wildfire smoke, have been extensively studied and Health Canada has evaluated the health risks of ambient PM_2.5 (that is, PM_2.5 from all sources combined) (Health Canada 2022). 

Government of Canada 

People who are exposed to smoke from wildfires, according to more recent scientific investigations, are increasingly assailed by lung-damaging toxins, but new discoveries identify that hearts, brains and other body organs are also being damaged by wildfire smoke. Smoke exposure could sound the death knell of up to 1.9 million people in the United States alone, over three decades, according to one 2025 study. Lungs can be penetrated deeply by the concentration of airborne particles known as PM2.5, from wildfires.

 

PM2.5 is a primary pollutant that air quality indexes measure, but fails to reflect other substances that can be contained in wildfire smoke that include lead, mercury and formaldehyde, cautions Karl Nadeau, dean of the University of California, Los Angeles Fielding School of Public Health. Preliminary research suggests that wildfire smoke may be of greater harm than air pollution from more common sources such as car exhaust. Fire in proximity to urban areas, moreover, may be of particular toxicity, through consuming buildings vehicles and electronics.

 

Smoke and flames from the Palisades Fire fill the sky as seen from the Pacific Palisades neighborhood of Los Angeles. | Getty Images

 

Associations between wildfire smoke and cardiovascular hospitalization, diabetes complications, preterm birth, cancer, impaired cognition and other problems, as well as respiratory effects including  attacks of asthma have been associated through scientific analytical studies. Wildfire smoke was linked in a 2024 study to deaths from cardiovascular, digestive, endocrine and kidney diseases. Asthma attacks and heart attacks can increase within an hour, in the presence of the severity of ambient smoke, pointed out professor Michael Brauer with the University of British Columbia.

 

Cognitive effect research has seen a significant expansion, explains Stephanie Cleland, associate professor at Simon Fraser University in British Columbia. Dr. Cleland was lead author of a 2022 study finding smoke exposure to be associated with lower scores on a 'brain training' game. A link between cumulative exposure throughout a school year and lower standardized test scores was also found through research, while other studies indicate a possible association with dementia. 

 

Less dramatic, lower-level exposures over time have an add-on impact, according to Professor Chen, who suggests the wearing of masks to be avoidance-helpful to exposure to ambient smoke during such events, not necessarily only when the surrounding air is redolent of burning, charred wood, and the atmosphere turns grey in reduced visibility with wildfire smoke. One study published in 2025 linked the risk of death from all causes with three-year exposure to wildfire smoke. Yet another 2025 study concluded that as average wildfire exposure increased, North Americans over age 65 suffered a higher risk of dying from chronic obstructive pulmonary disease.  

 

A woman wears an N95 mask to protect herself from high levels of smoke pollution. Daniiielc, Getty Images

 

"The data pretty clearly say that there is no safe level of exposure to wildfire smoke: the more exposure we get, the worse a range of health outcomes. The data also pretty clearly show that our notion of sensitive groups should probably be greatly expanded. In addition to kids, elderly populations, or anyone else with preexisting conditions, like asthma, we need to think about populations like pregnant people whose birth outcomes can be substantially affected by exposure. Portable indoor filtration is often the best option for many households, and well-fitting N95 masks can help when outside. "

"Climate change, and in particular increasing fuel aridity brought about by hotter temperatures and variable rainfall, is playing a central role in the recent rapid increase in wildfire activity and smoke exposure throughout the US. It is certainly not the only factor, but is substantially amplifying the risk brought about by other factors, which include a century of fire suppression that has left abundant fuels in our wildlands, as well as increased human construction and activity in the wildland-urban interface. We can say with strong confidence that climate change has made these events much more likely and much more severe."

Marshall Burke,  associate professor, Stanford Doerr School of Sustainability 

WHO Guidelines on Dementia

"While there is no cure for dementia, up to 45 percent of the risks can be attributed to modifiable risk factors such as tobacco, alcohol use, social isolation, physical inactivity, air pollution and noncommunicable diseases [NCSs], including high blood pressure and diabetes."

"Dementia can be caused by several diseases which over time damage the brain, typically leading to deterioration in cognitive function beyond what might be expected from the usual consequences of biological ageing. The impairment in cognitive function is commonly accompanied, and occasionally preceded, by changes in mood, emotional control, behaviour or motivation."

World Health Organization 

Dementia   World Health Organization

 

"Behind these numbers are individuals, families, and communities navigating profound challenges that affect not only health, but dignity, independence, and well-being."

"This is not a distant issue; it touches all of us."

Devora Kestel, director, WHO, NCDs and mental health department  

According to the World Health Organization, citing modifiable risk factors such as tobacco and air pollution, up to 45 percent of dementia risk could be prevented or delayed. As the seventh global leading cause of death, a major cause of disability and dependency among older people within the international community, this is no small thing, the caution that dementia can be caused by circumstances that can be altered in deliberate change of lifestyle geared to avoidance. 

 

Surrendering to physical lassitude, succumbing to a general disinterest in events around us, failing to remain cognitively engaged, to exercise brain and body, are all critical elements in wasting what we have. Worldwide over 57 million people live with dementia, while some ten million people are diagnosed with it annually. Alzheimer's disease, the most common form of dementia is estimated to make up 70 percent of diagnoses.   

Early signs and symptoms are:

• forgetting things or recent events
• losing or misplacing things
• getting lost when walking or driving
• being confused, even in familiar places
• losing track of time
• difficulties solving problems or making decisions
• problems following conversations or trouble finding words
• difficulties performing familiar tasks
• misjudging distances to objects visually.

Changes in mood and behaviour sometimes happen even before memory problems occur. Common changes include:

• feeling anxious, sad, or angry about memory loss
• personality changes
• inappropriate behaviour
• withdrawal from work or social activities
• being less interested in other people’s emotions.

An updated WHO guide was published recently focusing on how health workers and policy-makers can organize themselves to help in the prevention or delay of dementia onset. The first such dementia recommendations by the UN health agency was issued in 2019; since that time new evidence and understanding of dementia has grown significantly. 

 

Early awareness and intervention are addressed as critical issues on the guidelines, for the purpose of reducing he burden of dementia in years to come. The WHO is convinced that the condition is not an inevitable outcome of aging, although its onset is more common after age 65. "We know more today than ever before about what drives dementia risk, and these guidelines translate that knowledge into action", stated WHO chief Tedros Adhanom Ghebreyesus.  

"Dementia is caused by many different diseases or injuries that damage the brain. Alzheimer disease is the most common form and contributes to 60–70% of cases. Other forms include vascular dementia, dementia with Lewy bodies [abnormal deposits of protein inside nerve cells], and a group of diseases that contribute to frontotemporal dementia  [degeneration of the frontal lobe of the brain]."

"Dementia may also develop after a stroke, in the context of certain infections such as HIV, as a result of harmful use of alcohol, after repeated injuries to the brain, or because of nutritional deficiencies. The boundaries between different forms of dementia are not always clear and mixed forms often co-exist."

World Health Organization 

 Although age is the strongest known risk factor for dementia, dementia can also affect younger people, and young-onset dementia – in which symptoms begin before the age of 65 – accounts for up to 9% of cases.

Evidence suggests that people can reduce the risk of cognitive decline and dementia by adopting healthy behaviours and lifestyles, managing health conditions that are known to increase the risk for dementia, and reducing environmental risk factors.

Important actions include:

• being physically active
• not smoking
• avoiding harmful alcohol use
• eating a healthy, balanced diet
• staying socially and cognitively active
• maintaining a healthy weight
• managing blood pressure, cholesterol and blood sugar levels
• using hearing aids where needed
• reducing exposure to air pollution.

 

New Brunswick's Mysterious Brain Disease

Investigation of a Cluster of a Potential Neurological Syndrome of Unknown Cause in New Brunswick

"Unfounded concerns that a potentially fatal mystery disease, possibly induced by an environmental toxin, is causing the patients' neurological symptoms have been amplified in traditional and social media."

"Misinformation regarding this cluster [of patients] has proliferated in both traditional and social media, from not only the predictable and easily identifiable groups co-opting the crisis to suit their agenda, such as anti-vaccine advocates, but also those who are unknowingly amplifying an incorrect diagnosis from their physicians."

JAMA-published Study

A new study published in JAMA Neurology debunks “an alleged ‘mystery’ neurological illness” that emerged in New Brunswick six years ago. Photo by ALAIN JOCARD /AFP via Getty Images

 

A new study evaluating patients at two hospitals in New Brunswick and Ontario that identifies symptoms possibly traced back to known neurodegenerative and non-neurodegenerative conditions, published in the journal JAMA Neurology, posits no evidence in claims of a mystery brain disease that centres itself in New Brunswick. Close to 400 residents of New Brunswick in the Acadian Peninsula and Moncton areas reported symptoms of a "neurological syndrome of unknown cause".

 

Symptoms are inclusive of memory problems, balance issues, behavioural changes, muscle spasms and bursts of intense pain. In 2022, a team of six neurologists and other experts in medical health, formed under the former government found no evidence after their investigation of 48 patients, that a cluster of cases existed. In fact, 46 of the cases studied for their report had been referred by one specific neurologist. 

 

Once the list of patients reporting symptoms increased close to 400, the successive government committed to reopening the investigation. Authors affiliated with the University of Toronto, New Brunswick Horizon Health Network and other Canadian health institutions who had joined the updated study published in JAMA, support the initial research. Initial health records and follow-ups were studied between November 2023 and March of 2025, along with demographic data and autopsy reports when applicable.

 

According to the study's conclusions, conditions such as traumatic brain injury and metastatic cancer were identified in all 25 patients evaluated at New Brunswick's Horizon Health Network and Ontario's University Health Network. "Strong evidence" exists against an exposure to an environmental toxin which had been formerly posited as a source of the mysterious illness. The study pointed out that some of the patients' conditions were 'complex' warranting a second opinion: "However, it appears few patients sought this".

 

 The reputation of the illness as a "mystery brain disease", the study suggested related to a combination of the public's decreased trust in public health institutions in the wake of the COVID-19 pandemic, along with a widespread general misinformation aura. Data indicated that patients could be suffering from other diagnosable neurological conditions, which a multidisciplinary treatment might benefit them with. "Some patients", noted the study, rejected the diagnosis of a second opinion, preferring to believe they were suffering from an unknown neurological disease.

 

In the 2022 report, the New Brunswick Health Department attributed some symptoms to conditions such as Alzheimer's, dementia, Parkinson's, paranoid schizophrenia, chronic fatigue, severe anxiety disorder, and cancer. Chief medical officer of New Brunswick committed  his office to review 222 files with the Public Health Agency of Canada, to clarify issues surrounding the illness. 

"[Despite the small sample size], when we did the statistics … the chances of any of those other individuals having a mystery disease was less than one in a million. So the numbers are pretty staggering and, I think very, very convincing."

"The neurological problems varied a great deal. Some had neurodegenerative diseases, but others had other neurological problems and therefore a single environmental toxin … could never have explained this broad variety of neurological abnormalities."

"I think that if there really had been a mystery disease with those numbers, we would have been hearing from more than a single physician. … We would be seeing physicians raising red flags, raising awareness and concern that there was an epidemic of neurological diseases that could not be explained."

Dr. Anthony Lang, senior neurologist, neuroscientist, Toronto, among the 13 study co-authors

Of the 25 patients reassessed for the study, 14 are still living. (Shutterstock)

 

"Clear and transparent communication strategies to report the much-needed re-evaluations are required."

"Education, reassurance, and mental health support should also be prioritized for patients and families who have been profoundly impacted by claims that a potentially fatal mystery disease continues to affect them." 

JAMA-published Study

Brain Degeneration and Artistic Creativity

"He could not even utter a single word."

"[The study of artistic creativity as a signal of neurodegeneration remains unclear] whether overlapping brain mechanisms are responsible for generating an inspiring art piece or inventing a transformative technology."

Adit Friedberg, neurologist

"In neurology, we're so good at describing deficits."

"For me, and I think for most people, it was a paradox. It was not something we were trained to think about."

"I started to see people coming into my office who had carved ducks out of wood or who had welded beautiful insectlike creatures, or who had started painting."

Bruce Miller, neurologist, director of UCSF Memory and Aging Center

Dr. Friedberg was confronted with a puzzle, that a man who had lost the ability to understand or to produce words, diagnosed with primary progressive aphasia (a form of frontotemporal dementia -- FTD), had suddenly developed a sense of visual creativity. The wife of one such patient of hers, presented her with a stack of her husband's creative work, asking, "What is he trying to tell me?"

Credit: Thomas Fuchs

As their brains degenerate, there are some people who may develop increased visual creativity. Until a recent study led by Dr. Friedberg and associates, the underlying mechanism that led to this development was a mystery. Their study uncovered the potential brain structures involved, and the connections between them. 

They concluded that sudden development of new strengths like artistic creativity could in fact be a signal of neurodegeneration -- an understanding that could lead to earlier monitoring and perhaps improved treatment. Her experience with that patient led Dr. Friedberg -- then completing residency at Tel Aviv Sourasky Medical Center -- to begin looking into scientific literature hoping to find evidence of links between neurodegeneration and artistic creativity.

Which was when she came across the case of Anne Adams in a 2008 study conducted by neurologists Bill Seeley and Bruce Miller, along with their colleagues at the University of California at San Francisco. The case revolved around Dr. Adams, a scientist who left academia in her 40s, to care for her son after a serious car accident. She began painting and never returned to the laboratory, becoming obsessed with art while signs of FTD; primary progressive aphasia; emerged.

FTD represents a group of neurodegenerative disorders in the frontal and temporal lobes of the brain, caused by the death of neurons in regions that control social behaviour and language, respectively. Dr. Friedberg was struck by the "hidden potential that can be evoked in the setting of disease". At the time a research fellow at the UCSF Memory and Aging Center, Dr. Friedberg led the study with Drs. Miller, Seeley and other colleagues.

 The first case report of visual artistic creativity in someone with FTD was published by Dr. Miller in 1996, of a patient who had not been an artist, but suddenly "became obsessed with painting". Dr. Miller began encountering more FTD patients with visual artistic creativity. Hypotheses to explain how enhanced creativity could arise in patients with deteriorating brains were outlined for decades in case studies.

 

Examples of one patient’s artwork over the years after she was diagnosed with FTD. Courtesy Paige Spence-Berthiaume and Padgett Berthiaume

As regions of the brain break down, the leading theory believed, regions further behind in the brain including those involved in vision increase compensatory activity. Little data was available and the researchers realized "a group study was needed" to help identify patterns between and unique to patients. 

Dr Friedberg initiated the first FTD group study by evaluating hundreds of patient records collected between the years 2002 and 2019. Of that total she identified 17 FTD patients with visual artistic creativity, matching them to both healthy control subjects and FTD patients failing to show creativity, allowing the research team to investigate which brain changes related to FTD and which unique to patients with FTD and visual artistic creativity.

With the use of patient structural magnetic resonance imaging (MRI) data showing brain tissue structure and size unique to patients with FTD, they were able to perform atrophy network mapping, a technique comparing a patient's brain to a non-diseased human brain to determine what the patient's damaged region is connected to, along with how those connected regions could increase or decrease their activity. Another milestone in understanding the complex and variable issues of brain activity and degeneration.

An example of Anne Adams’ artwork after she was diagnosed with FTD. Visual representation of Maurice Ravel’s Boléro Courtesy Anne Adams/UCSF Memory and Aging Center

Pathway to An Alzheimer's Solution

"This is a very important and interesting finding."

"For the first time we get a clue to how and why neurons die in Alzheimer's disease. There's been a lot of speculation for 30 to 40 years, but nobody has been able to pinpoint the mechanisms."

"It really provides strong evidence [that] it's this specific suicide pathway."

Professor Bart De Strooper, U.K. Dementia Research Institute

 

"That is a cool paper." 

"[It] addresses one of the fundamental gaps in Alzheimer's research… these are fascinating results and will be important for the field moving forward."  

"[However], many steps are needed [before knowing whether it could be harnessed as an effective treatment for Alzheimer's]."  

Professor Tara Spires-Jones, University of Edinburgh, president, British Neuroscience Association

 

"[The findings are] exciting [but still at an early stage]." 

"This discovery is important because it points to new mechanisms of cell death in Alzheimer's disease that we didn't previously understand and could pave the way for new treatments to slow, or even stop disease progression in the future."

Dr Susan Kohlhaas, Alzheimer's Research UK 

Groundbreaking new research into the cause of brain cell death in Alzheimer's patients has revealed that they're undergoing necroptosis, a form of cell suicide   Getty Images

Research published in the journal Science concludes that Alzheimer's might cause brain cells to eliminate themselves. Scientists studying mice were led to that conclusion when their research brought them to realize that when tangles of the tau protein begin to appear in the brain, a molecule that triggers necroptosis is produced; the elimination of unwanted cells, a method used by the body. A buildup of abnormal proteins, tau and amyloid are seen in Alzheimer's patients.

Amyloid accumulates in spaces between neurons, leading to brain inflammation, causing neurons to alter their internal chemistry, the researchers believe. Gradually brain cells begin to die as tau tangles start to appear. Brain cells survived, the scientists discovered, when the protein MEG3 blocked the protein that triggered the cell suicide. Researchers believe that drugs produced to mimic that effect could prevent necroptosis from occurring.

An estimate of 944,000 people in Britain suffer from dementia, the majority with Alzheimer's -- a number expected to increase to over a million by the year 2030, affecting one in three people born in the United Kingdom this year, expected to develop dementia during their lifetime. The cost of treating the condition and in lost functionality costs Britain $58.1 billion annually. 

Alzheimer's is now identified as the leading cause of death in the country. Drugs currently prescribed for the condition help with the symptoms but are unable to halt its progression.

Researchers believe new findings about a form of cellular suicide gives new ideas for treating Alzheimer's   Getty Images

"The brain typically shrinks to some degree in healthy aging but, surprisingly, does not lose neurons in large numbers. In Alzheimer’s disease, however, damage is widespread, as many neurons stop functioning, lose connections with other neurons, and die. Alzheimer’s disrupts processes vital to neurons and their networks, including communication, metabolism, and repair."

"At first, Alzheimer’s disease typically destroys neurons and their connections in parts of the brain involved in memory, including the entorhinal cortex and hippocampus. It later affects areas in the cerebral cortex responsible for language, reasoning, and social behavior. Eventually, many other areas of the brain are damaged. Over time, a person with Alzheimer’s gradually loses his or her ability to live and function independently. Ultimately, the disease is fatal."

National Institute on Aging (U.S. government official website)

Expanding Life Interests to Challenge the Aging Brain

"'Use it or lose it' is not just a hypothesis, it's a basic biologic[al] fact that holds as true for our brains as our muscles or our bones."

"[While the loss of muscle is a visual thing and the health of our skeleton can be measured with bone density scans], it is only recently that we were aware the same reality was evident in our brains."

David  Merrill, adult and geriatric psychiatrist, director, Pacific Brain Health Center, Santa Monica, California

"The fact is that there are many positive cognitive changes in older age and there are many techniques to support lifelong learning. Older persons can benefit from the same memory strategies that young persons use to improve recall."

"In fact, our brains experience new growth of neurons in response to challenges throughout the lifespan."

Becca Levy, professor of psychology and epidemiology, Yale University

"Imagine on retirement you decide to take up dancing lessons. [Ultimately] you're not just benefiting from the cognitive challenge -- learning new steps -- you're also likely more socially engaged and more active. And because you're more active, you may think about your diet, so before you know it, you've embraced a number of important lifestyle changes."

:Having a plan is critically important. How am I going to keep busy, stay engaged, remain active?"

Monica Moreno, senior director, care and support, Alzheimer's Association

In the United States alone, an estimated 5.8 million adults over age 65 live with Alzheimer's disease or another type of dementia disorder, according to the Centers for Disease Control and Prevention. The Alzheimer's Association places the number as one in nine Americans over 65 having Alzheimer's. A situation that may be undergoing a slow change as more people focus on elder lifestyle changes, incorporating renewed interests in activities new to them that in the process activate exercise in both mind and body for a healthier outcome.

Interests to be developed with a focus on exerting oneself both mentally and physically. The goal is to achieve better health, and to stave off the effects of a wasting body and brain, declining with age. Like any other part of the human body, brains need stimulation and use. There are no guarantees in the prevention of dementia, and there is as yet no cure for the condition. In 2020 the medical journal Lancet identified a dozen potential risk factors open to modification that could lead to or forestall the condition.

• Physiological (blood pressure, diabetes, hearing loss);
• Lifestyle choices (smoking, drinking, physical inactivity);
• Environmental (air pollution);
• Depression;
• Social Isolation;
• Lower level of education.

To help minimize the risk of dementia onset the Alzheimer Society of Canada offers the advice to maintain cognitive engagement; learn new things; meet new people; keep a diary; remain curious; and engage in conversations. Brain imaging demonstrates the point that disease atrophy seen in sedentary muscles reflects the cognitive decline identified in dementia. Being engaged, learning new things contributes to building both psychological and physiological lift in brain volume preservation and atrophy prevention of memory centres, just as physical exercise keeps muscle in shape.

 

Focus on challenging our brains through tackling difficult tasks; cognitive weightlifting requiring flexible mental tasking and strength. Taking the brain in a new direction to understand and perform in a commitment to learn a new discipline, such as another language is prime exercise for the brain. When we're young our sense of curiosity leads us to learning new things, an enterprise that lags as we grow older and begin to slow down, tending toward the sedentary and the damping of interests.

 

There is also the issue of: you are what you think you are. If you are resigned to being 'old' because you think that's the condition you've slid into, considering that it is appropriate to no longer be active or to bother yourself over intellectual pursuits, your perception of what you are will guide you to behave in a like manner, settling for agedness and becoming decrepit, susceptible to impaired health and body breakdown. Think old, become 'old' a self-fulfilling prophecy.

"Based on a large scientific literature, our general sentiment is that it is never too early or too late to engage in physically and mentally stimulating activities."

"We think of these healthy activities as a savings account for the brain."

"Begin building that cognitive reserve now, so the money is in the bank for down the road if our brains need it."

Judy Pa, co-director, Alzheimer's Disease Cooperative Study, University of California, San Diego

Linking Hearing Loss and Dementia

"It's really common, it's treatable, and there are interventions that come at no risk [that are underutilized]."

"[Preserving the ability to hear is foundational to public health] strategies that can best optimize the health of older adult populations, so older adults are living a long and full life 'till the very, very end."

"[Like daily step count, cholesterol level or weight], it's another metric that you would know about a dimension of your own health."

Dr. Frank Lin, director, Cochlear Center for Hearing and Public Health, Johns Hopkins Bloomberg School of Public Health

Global statistics tell us that worldwide, over 50,000 million people since 2019 are living with dementia. The forecast to the year 2050 is that the number will rise to over 130 million people in an aging population coping and living with dementia. Middle age hearing loss beginning at age 45 to 66 is considered by science to represent a significant risk factor for dementia. Hearing loss accounts for over eight percent of all dementia cases.

A Lancet report published in 2020 calculated that hearing loss generally doubles risk of dementia, similar to the increased risk caused by traumatic brain injury. Since hearing ability exists on a continuum, subclinical hearing loss can also contribute to a greater risk for dementia arising. According to Dr. Frank Lin, director of the Cochlear Center for Hearing and Public Health, remedially addressing hearing loss is a superior method of reducing the occurrence of dementia.

There is a hypothesis that suggests poor hearing increases the cognition load on the brain which in turn needs to work harder at the expense of other mental faculties in its attempt to decipher the garbled signals ears send to the brain when they're compromised. On the other hand, those with hearing loss and declining cognition struggle as well on tests not dependent on hearing, according to Dr. Tim Griffiths, professor of cognitive neurology, Newcastle University, Britain.

Animal model research and those with humans find that loss of hearing causes the brain to atrophy faster, particularly in the temporal lobe, possibly as a result of diminished use and lack of stimulation. Aberrant activity in the temporal lobe may also be caused by hearing loss, rendering it more susceptible to damage and pathologies associated with Alzheimer's disease, explains Dr. Griffiths.

Hearing loss -- the inability to connect with others -- can lead to social isolation, loneliness and depression, all factors known for the risk of dementia onset. The cochlea's sensory cells in the inner ear leads us to hear. Hair cells are sensory cells that translate the vibration of sound waves hitting eardrums into electrical signals sent to auditory regions of the brain to be decoded into sound.

Once hair cells become degraded or expire, the signals sent to the brain become garbled. Hair cells cannot be regenerated. Preliminary studies appear to affirm that the use of hearing aids tend to protect against dementia. Dr. Lin at the Johns Hopkins Bloomberg School of Public Health currently leads a large, randomized controlled trial with close to a thousand older adults in anticipation that the answer will more definitively emerge as to whether treating hearing loss with hearing aids reduces risk of cognitive decline.

Johns Hopkins Bloomberg School of Public Health

We Have Seen The Future -- And Hope It's Not Us

"These estimates will allow policymakers and decision makers to better understand the expected increases in the number of individuals with dementia as well as the drivers of these increases in a given geographical setting."

"The large anticipated increase in the number of individuals with dementia emphasizes the vital need for research focused on the discovery of disease-modifying treatments and effective low-cost interventions for the prevention or delay of dementia onset."

Emma Nichols, MPH, researcher, Institute for Health Metrics and Evaluation, University of Washington School of Medicine

 

"Dementia is our greatest long-term medical challenge."

"These striking figures, from the latest American research, lay bare the shocking global scale of dementia."

"To have 57 million people already living with this devastating condition is 57 million too many. However, with that number set to almost triple, we need to see concerted global action now to transform the prospects for the next generation."

"There is robust evidence that what's good for the heart is also good for the brain. Not smoking, only drinking within the recommended limits, staying mentally and physically active, eating a balanced diet, and keeping blood pressure and cholesterol levels in check can all help to keep our brains healthy as we age."

Hilary Evans, chief executive, Alzheimer's Research U.K.

 

"Improvements in lifestyle in adults in developed countries and other places -- including increasing access to education and greater attention to heart health issues -- have reduced incidence in recent years, but total numbers with dementia are still going up because of the aging of the population." 

"In addition, obesity, diabetes and sedentary lifestyles in younger people are rising quickly, and these are risk factors for dementia."

Dr. Maria C. Carrillo, chief science officer, Alzheimer's Association 

Researchers from the University of Washington School of Medicine, led by Emma Nichols, presented their findings at the Alzheimer's Association International Conference taking place in Denver, Colorado. The research, published in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association, by Dr. Nichols and her team of researchers concluded Alzheimer's mortality rates increased by 38.0% between 1990 and 2019.

 

The research team led by Dr.Nichols made it clear that the prevalence of dementia in the public arena can be attributed to factors such as smoking, high body mass index (BMI) along with high fasting plasma glucose. The risk factors between these issues and the onset of dementia is a relationship that can be interrupted with public education, in their opinion. Between 2019 and 2050 they theorized an increase of global dementia cases of 6.2 million directly related to such risk factors.

On the other hand, they also found that changes in education levels as a natural consequence of teaching the public about risk and avoidance has the potential to lead to a decline in the prevalence of dementia of some 6.2 million people globally between that same period of 2019 to 2050. These opposing trends would seem to cancel each other's impacts on the prevalence of the disease.

In total their prediction for the number of individuals contracting dementia is a tripling in 30 years' time, with 152 million people affected internationally by 2050, according to international projections. Much of that increase is expected to be based on growing population numbers, along with a steadily aging population base. 

According to the University of Washington School of Medicine researchers' calculations the number of people living with the condition in 2019 was an estimated 57 million worldwide, with trends moving the total to the point where it is set to climb by 2050 to a total of 152 million. Sub-Saharan Africa, North Africa and the Middle East are three areas where a surge in dementia is seen to be fuelling global numbers.

In Britain, however, the rate of increase may, according to recent data, be decelerating. Chief executive of Alzheimer's Research U.K., Hilary Evans speaks of encouraging populations to make "positive lifestyle changes" for the purpose of "help[ing to] tip the scales in our favour" of reducing the opportunities for the condition further developing.

Researchers at Maastricht University in the Netherlands produced the results of their own study, estimating that annually about ten new cases per 100,000 people of "young onset" dementia emerge. This is the form of dementia discovered among people of age 65 and younger.

Calculating Dementia Risk

"What sets this dementia risk calculator apart is that you don't need to visit a doctor for any tests."

"People already have all the information they need to complete the calculator in the comfort of their home."

Dr.Stacey Fisher, study lead author, University of Ottawa

"This tool will give people who fill it out clues to what they can do to reduce their personal risk of dementia."

"The COVID-19 pandemic has also made it clear that sociodemographic variables like ethnicity and neighbourhood play a major role in our health."

"It was important to include those variables in the tool so policy makers can understand how different populations are impacted by dementia, and help ensure that any prevention strategies are equitable."

Dr.Peter Tanuseputro, study senior author, University of Ottawa, The Ottawa Hospital

Researchers have built and validated an online calculator that empowers individuals 55 and over to better understand the health of their brain and how they can reduce their risk of being diagnosed with dementia in the next five years.  Project Big Life

 

An online calculator has been placed on a dedicated website for anyone's use thanks to the work of researchers out of the University of Ottawa. The site -- projectbiglife.ca/dementia -- predicts a person's risk over the next five years of developing dementia. Based on survey results of over 75,000 Canadians, it uses age, lifestyle factors, weight and previous health conditions to render a percentage risk of developing dementia.

Each participant in the study that ran for close to two decades was followed for an average of a decade. Findings were published in the Journal of Epidemiology and Community Health online. The dementia platform also was posted live online.

It takes about five minutes to complete the online questionnaire meant exclusively for people 55 years of age and over, and according to the scientists involved in its creation, is 83 percent accurate. While there are other online calculators present on the Internet, few have the scientific background data support that this one can boast.

The data gathered by the scientists in their Dementia Population Risk Tool (DemPoRT), form the backbone of the questions posted on the dementia tool. The critical factors taken into account are age, smoking status and lifetime exposure, alcohol consumption, physical activity, stress, diet, sense of belonging, ethnicity, immigration status, socioeconomic status of neighbourhood, education, activities where assistance is required, marital status, languages spoken, and health conditions.

The individual responding to the questionnaire is given, based on their answers to the questions, their personal relative level of risk, along with 'advice' in the form of focusing on aspects of their life where changes can be made for the purpose of reducing risk.

An elderly couple walks down a hall in Easton, Pa. Research released on Friday, Nov. 1, 2019 suggests many American adults inaccurately estimate their chances for developing dementia and do useless things to prevent it. (AP Photo/Matt Rourke, File)

The Grim Diagnosis of Alzheimer's Disease

"Neurodegeneration is a general term that we use when cells and their connections don't work properly, which means there isn't proper communication between brain cells."

"This affects basic physiological functions such as memory and the ability to store and receive information which is what happens when someone has Alzheimer's."

Dr.Jack Jhamandas, professor, University of Alberta

 

"Memories are stored in our synaptic connections and to retrieve them our brain has to release the correct chemical to allow communication to happen."

"When someone has Alzheimer's, sometimes this works and sometimes it doesn't."

"The initiating event happens early on, maybe even decades before someone shows up to the doctor's office with symptoms."

"That's where the problem is; we don't know what the real underlying initiating events are or when they start, which makes it difficult to devise treatments. In a sense, you're trying to work backwards; you don't know who the affected individuals will be because it could be ten to 20 years before they start to show symptoms."

Dr.Jane Rylett, professor, scientist, Western University. Scientific director, CIHR Institute of Aging

Alzheimer's Society of Canada

First described in 1906, Alzheimer's disease after a century of research and billions spent on that research, the complex brain disease is still little understood, and a long way off from a cure. As a neurodegenerative disease impacting memory, thinking and behaviour, a cruelly merciless undermining of personality and personhood, and the body's slow descent into full malfunction in lockstep with that of the brain and all associated functions, the disease continues its fearful inroads in the elderly population worldwide.

Science is of the opinion that three main events lead to Alzheiner's; that the first of which is the amyloid protein which builds up to form toxic plaques in the brain; added to that is neurofibrillary tangles (abnormal accumulations of the tau proteins in the brain), and finally, inflammation in brain cells and the role this plays in accommodating toxins entering the brain. When these three main malfunctions occur complementarily, cells no longer function, they die off, leading the brain to shrink.

What causes these proteins to build and the brain to become inflamed however, remains a mystery to science. Approximately five percent of Alzheimer's cases can be traced to genetic predisposition, but science puzzles over what might catalyze the events leading to Alzheimer's in the aggregate 95 percent of Alzheimer's cases.

A range of brain disorders are known generally as dementia, the impact of which is memory loss, diminished thinking and affected behaviour. The most common form of dementia is recognized as Alzheimer's disease which accounts for roughly 80 percent of all dementia cases, while many other form -- including vascular dementia, the result of small strokes in the brain, and Lewy body dementia which frequently has an effect on mobility -- are also part of the dementia family of diseases.

 

When Alzheimer's is at work destroying brain and body function, amyloid protein plaques become deposited in the cortex and hippocampus areas of the brain, both important for learning, and memory. With the progression of the disease, amyloid plaques and tau proteins start their destructive increase in other parts of the brain, impacting areas responsible for language and behaviour, among others. In early stages of Alzheimer's, many people remain capable of retrieving memories, but that capacity shrinks as the disease carries on and connections break down, resulting in memories fading from recall.

 

Countless attempts have taken place focusing on two major areas of drug research; first drugs that bind to and destroy amyloid plaques or prevent plaques from forming. The second route targets the tau protein responsible for forming tangles. According to Doctors Rylett and Jhamandas, nothing thus far has borne positive results and they speculate that this may possibly result from the fact that over time as the disease progresses the brain undergoes years of change before it is even clear that Alzheimer's is in the picture.

Leading to the hypothesis that the brain could possibly be, at that juncture, too critically damaged for a drug to reverse or prevent impairments. With Alzheimer's, frustratingly, there is no cure, but there are drugs that help to reduce symptoms in the short term. The drugs represent two broad categories; acetylcholinesterase inhibitors and memantine; the former to boost levels of the chemical messenger acetylcholine which has a vital role in memory retention and exists in abnormally low levels in those with Alzheimer's.

 

Glutamate is regulated by memantine, a treatment used in later stages of the disease; the glutamate an important chemical messenger that becomes impaired with Alzheimer's. Research indicates that exercise, a healthy diet and social interactions are associated with better brain health and thus those whose lifestyle includes those elements stand at lower risk of developing Alzheimer's. 

 

Research has been focusing on the development of a biomarker which, according to Dr.Rylett, could potentially take the form of a blood test or imagining test.

"The idea is these biomarkers would be predictive of who is at highest risk of developing Alzheimer's or other dementias at some point in their lives."

"If we knew that first, then we could start looking at other drug and lifestyle choices that could impact the course of trajectory of the disease."

National Institute on Aging

Flavonols: Reducing Risk of Alzheimer's

"Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer's."
With the elderly population increasing worldwide, any decrease in the number of people with this devastating disease, or even delaying it for a few years, could have an enormous benefit on public health."
"This study is a piece of the puzzle for anybody wanting to think about benefits for Alzheimer dementia or disease. We need to think about it as a lifestyle modification."
Dr.Thomas Holland, researcher, Rush University, Chicago

Microcosm diagram of the mind by Robert Fludd

"Following a 'healthful diet pattern', which includes a variety of foods such as fruits, vegetables, oily fish, seeds, nuts, legumes, is known to be a good approach to chronic disease prevention rather than focusing on particular nutrients."
"This is important because the public might wrongly think about the term 'antioxidant' as a magic pill that will prevent the onset of dementia."
"It is important to remember that consuming isolated flavonols or extracts of flavonol-rich foods, for example tea extracts, will not work in isolation to reduce risk of disease but high doses can also have negative effects."
Dr.Ada Garcia, lecturer in public health nutrition, University of Glasgow

A link has been established to flavonols -- an antioxidant found in plant pigments and present in almost all fruits and vegetables, as well as tea -- and Alzheimer's avoidance, according to a new study out of Rush University in Chicago, led by Dr. Thomas Holland.

The researchers tracked more than 900 elderly people for an average of six years, to determine what they ate and drank, (through self-reporting), while monitoring who among them later developed Alzheimer's. Divided into five groups based on the amount of flavonol in their diet, those in the group (all of whom had an average age of 81) who ingested the most flavonols were 48 percent less likely to be afflicted with Alzheimer's disease.

About 16 to 20 milligrams per day was established as the average preferential amount of intake of flavonol. The study found that the lowest group's intake was 5.3 milligrams daily and that the highest group consumed on average 15.3 milligrams on a daily basis. Research previously undertaken had placed the quantity of flavonols in an average size cup of tea between eight and 15 milligrams. The recommendation is for three cups of tea daily to achieve maximum flavonol intake.

Fruits, vegetables, tea, wine may reduce risk of Alzheimer’s. (CP/Paul Chiasson)

Of the 186 people in the highest group, 28 (representing 15 percent), developed Alzheimer's, in comparison to 56 people (30 percent), of the 182 people in the lowest intake group. When researchers adjusted for other factors which could affect Alzheimer's dementia risk such as diabetes, previous heart attack, stroke and high blood pressure, the results were the same.

Flabonols were broken down into four types: isorhamnetin, kaempferol, myricetin and quercetin. In each category the top food contributors were pears, olive oil, wine and tomato sauce for isorhamnetin; kale, beans, tea, spinach and broccoli for kaempferol; tea, wine, kale, oranges and tomatoes for myricetin; and tomatoes, kale, apples and tea for quercetin.

Both a kale salad and a glass of wine are rich in flavonols, linked to a lower risk of Alzheimer's disease. (Andrew Purcell)

The flavonols with a high intake of isorhamnetin left people with a 38 percent less likelihood of developing Alzheimer's, while those with a high intake of kaempferol were 51 percent less likely to develop dementia, and those with a high intake of myricetin were also 38 percent less prone to developing dementia. The data did not prove however, that a link existed between flavonols and Alzheimer's.

The possibility is there that other properties common to products high in antioxidants good for the brain might be involved. But there is fairly well unanimous acknowledgement on the part of scientists in the field of public health nutrition that a variety of foods considered to be high in nutritional value with a focus on fruits, vegetables, fish seeds, nuts and legumes represent the pathway to optimum health outcomes.

Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer's dementia, say researchers.

Hope For Alzheimer's

"Photobiomodulation introduces the therapeutic effect of light into our brain. It triggers the body to restore its natural balance or homeostasis. When we do that, we call upon the body's innate ability to heal."
"We have a much bigger ambition than the drug trials. Drug developers are mainly either seeking to slow the mental decline in diagnosed cases, or to prevent the onset of Alzheimer's disease by intervening at the pre-symptomatic stage."
"Based on early data, we are confident of seeing some measure of recovery in the symptoms, not just a slowdown in the rate of decline, even in moderate to severe cases."
Dr.Lew Lim, CEO, Vielight Inc.

The Vielight Neuro RX Gamma device in use.

In Canada, an estimated half-million Canadians are living currently with Alzheimer's disease. In the United States that number is around 5.8 million. New cases diagnosed every year number around 25,000 in Canada, a total number expected to rise in Canada by 66 percent for a total of 937,000 people by the year 2031. Since the U.S. has about ten times the population of Canada, the diagnosed incidence of Alzheimer's onset is quite similar in each population base. Worldwide the number of those living with Alzheimer's is around 50 million, although it would appear that only one in four sufferers has been diagnosed, according to Alzheimer's Disease International.

"In spite of substantial efforts to establish effective treatments for Alzheimer’s disease, progress has been, unfortunately, limited and a cure does not yet exist."
"Although not conventional as an Alzheimer’s disease solution, we look forward to investigating the potential of Vielight’s technology in the treatment of this difficult disease based on promising early evidence."
Dr. Corinne Fischer, principal investigator, St.Michael's Hospital, Toronto

The light is directed at specific areas of the brain known to be damaged in Alzherimer's Credit: Vielight

Currently, there is no treatment for Alzheimer's to cure the condition or to prevent its onset, although drug treatment has succeeded in slowing its progress in a minor way. The drug that appeared to give the most hope for the future, Biogen's aducanumah has been seen to slow dementia onset, but that appears the extent of its efficacy. No new drugs have been developed in almost two decades. Scientists have by and large surrendered their hope of reversing brain damage, once it has occurred.

On the near horizon, however, another treatment has recently emerged and has undergone initial clinical trials.

Resulting in the first major trial to determine whether light therapy might turn out to be beneficial for dementia. Early findings have astounded the scientific world, when people have been seen to regain memory, their reading and writing capability and have realized restored orientation, all negatively impacted and increasingly diminished by Alzheimer's. Should the trial ultimately be deemed successful it would represent the first treatment enabling the reversal of the disease's steady brain and body decline.


The focus of the trial is a device named the Neuro RX Gamma headset, developed by Vielight, a biotech company based in Toronto. A process called "photobiomodulation" has been devised where parts of the brain known to be damaged in dementia are exposed to pulses of near-infrared light. Using LEDs on a headset, the device fires 4 Hz gamma waves directly into the skull. The hippocampus, part of the brain connected to memory, sees additional light channeled up the patient's nose by use of a separate nasal clip.

A pilot trial to test the effects of home photobiomodulation (PBM) on cognitive and behavioral function, cerebral perfusion and functional connectivity in eight patients with dementia was administered in a home setting three times weekly with the use of the Vielight Neuro Gamma device pulsing at 40 Hz. Participants were assessed at 6 and 12 weeks. Following 12 weeks of use improvements were seen in all indices. Should the trial prove to be the success that early results appear to indicate, people suffering with Alzheimer's would be able to self-administer their treatments at home with use of the light-emitting device.

Alzheimer’s is the most common cause of dementia among older adults. Dementia is the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities to such an extent that it interferes with a person’s daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of daily living.

The causes of dementia can vary, depending on the types of brain changes that may be taking place. Other dementias include Lewy body dementia, frontotemporal disorders, and vascular dementia. It is common for people to have mixed dementia—a combination of two or more types of dementia. For example, some people have both Alzheimer’s disease and vascular dementia.

National Institute on Aging, U.S.