
Car Emissions, Air Pollution Linked To Higher Dementia Risk: Study
Regular exposure to air pollution, including that coming from car exhaust emissions, can increased your risk of dementia, according to an analysis of studies published on Friday.
Dementias such as Alzheimer's disease are estimated to affect more than 57.4 million people worldwide, a number that is expected to almost triple to 152.8 million cases by 2050.
The study, published in the journal The Lancet Planetary Health, showed that for every 10 micrograms per cubic metre of PM2.5, an individual's relative risk of dementia would increase by 17 per cent.
For each 1 micrograms per cubic metre of soot as found in PM2.5, the relative risk for the cognitive condition increased by 13 per cent. Soot comes from sources such as vehicle exhaust emissions and burning wood.
"These findings underscore the need for an interdisciplinary approach to dementia prevention. Preventing dementia is not just the responsibility of health care: this study strengthens the case that urban planning, transport policy, and environmental regulation all have a significant role to play," said joint first author Dr. Christiaan Bredell from the University of Cambridge.
Air pollution causes inflammation in the brain and oxidative stress (a chemical process in the body that can cause damage to cells, proteins, and DNA), leading to the onset and progression of dementia.
"Tackling air pollution can deliver long-term health, social, climate, and economic benefits. It can reduce the immense burden on patients, families, and caregivers, while easing pressure on overstretched health care systems," said Dr. Haneen Khreis from the MRC Epidemiology Unit.
For the study, the team carried out a systematic review and meta-analysis of existing scientific literature. They included 51 studies, including data from more than 29 million participants, mostly from high-income countries. Of these, 34 papers were included in the meta-analysis: 15 originated in North America, 10 in Europe, seven in Asia, and two in Australia.
The researchers found a positive and statistically significant association between particulate matter with a diameter of 2.5 microns or less (PM2.5), Nitrogen dioxide (NO2), and soot and dementia.
Further analysis revealed that the effect of exposure to these pollutants was stronger for vascular dementia -- a type of dementia caused by reduced blood flow to the brain.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles


Time of India
a day ago
- Time of India
‘Alzheimer's can be prevented & reversed', says expert; early intervention, natural therapies & Covid link
Prof Ram Shankar Upadhayaya , a medical scientist and an expert in infectious diseases and molecular oncology, believes that there is hope for Alzheimer's patients and says that it is completely reversible. Tired of too many ads? go ad free now Talking to TOI , he speaks about the evolving understanding of Alzheimer's and the way ahead. Excerpts: You say that Alzheimer's is reversible. Could you explain how? When I began my journey as a scientist decades ago, even during my time at Harvard, the consensus was that Alzheimer's could only be definitively diagnosed post-mortem and that there was virtually no hope for reversal. But today, we stand on a very different frontier. Our evolving understanding, supported by multi-omics, neurobiology, and functional medicine, tells us that Alzheimer's is not a singular condition with a singular cause. It is a syndrome with 100 different potential root causes, ranging from chronic inflammation and vascular compromise to environmental toxins, metabolic dysfunction, and infections. Once you accept that, the strategy shifts from 'waiting for a cure' to actively identifying and reversing the drivers in each patient. Could you break down what makes Alzheimer's distinct from dementia? Dementia is a broad term. It simply means that the brain isn't working the way it used to whether it's memory, decision-making, emotional processing, or cognition. Alzheimer's is a specific disease, the most common form of dementia, responsible for about 70% of cases in older adults. But not all dementia is Alzheimer's. Trauma, tumours, vascular issues, or infections can lead to dementia-like symptoms that are reversible if the underlying cause is treated. You say that Alzheimer's begins decades before symptoms appear. Can you elaborate? That's one of the most important insights. Alzheimer's pathology starts 20-30 years before the first symptom. The brain begins accumulating damage, amyloid plaques, tau tangles, inflammation, vascular compromise all silently. That's why early intervention is key. The earlier we can detect cognitive shifts and investigate root causes, the better our chances of slowing, halting, or even reversing the condition. You mentioned hundreds of causes. Isn't that overwhelming? It can be, but it also means there are many opportunities to intervene. One-size-fits-all medicine won't work. Instead, we assess each patient's environment, genetics, exposures, metabolic state, infections, and more. We've seen success using lifestyle-based protocols optimizing sleep, detoxification, nutrition, and exercise. For example, deep sleep (N3 stage) is critical. Every 1% reduction in N3 sleep increases Alzheimer's risk by 22%. Yet, most in the age group of 65-80 only get 15-30 minutes of N3 sleep. That's modifiable. Are there examples of patients you've treated using this approach? There are studies, patients reverse cognitive decline using protocols including Lion's Mane mushroom, Rosemary essential oil, detoxification, targeted anti-inflammatory therapies, and in some cases, cutting-edge interventions like Galectin-3 antibody therapy, which is showing remarkable promise without the side effects seen in amyloid-targeting drugs. Can Covid-19 or its vaccine exacerbate or even trigger neurodegeneration? We're seeing clear signals that both Covid-19 and spike proteins from vaccines may accelerate neuroinflammation in predisposed individuals, particularly those with high toxic burdens, poor sleep, chronic infections, or autoimmunity. But it's important to remember this is a layered phenomenon. Covid didn't create Alzheimer's, but it may tip the balance in vulnerable individuals. One UK post-mortem study even showed 5-10% brain mass shrinkage in individuals who had only mild Covid. What role does lifestyle play in Alzheimer's prevention? Alzheimer's doesn't start in the brain; it starts in the body. The way we live, our sleep patterns, food, activity levels, toxic exposures all influence cognitive longevity. Exercise increases BDNF, a growth factor that stimulates new neuron and synapse formation. Sauna therapy promotes detoxification and triggers heat shock proteins that may regenerate neural tissue. Diets high in processed sugar, salt, and seed oils are inflammatory and vascularly destructive, both are enemies of the brain. You say Alzheimer's not as a tragedy but as a call to action. What's your message?


Time of India
a day ago
- Time of India
THIS silent threat around is eating away at the brain, even increasing the risk of dementia
A recent study reveals a concerning link between long-term exposure to air pollution and an increased risk of dementia, including Alzheimer's and vascular dementia. Researchers found a statistically significant association between pollutants like PM2.5, nitrogen dioxide, and soot, and a higher incidence of dementia. This silent threat is around us. It's not invisible, but yet overlooked. And the destruction it causes? Brain damage. We are talking about a common health threat that is secretly lurking around us. A new study has revealed that long exposure to this hazard can increase the risk of developing dementia, including Alzheimer's disease and vascular dementia, conditions which were earlier believed to be mainly linked with lifestyle and genetics. A study led by the researchers at the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge found that long-term exposure to outdoor air pollution can increase the risk of dementia. The findings are published in The Lancet Planetary Health . Dementia is on the rise worldwide Dementia, such as Alzheimer's disease, affects more than 57.4 million people worldwide. This number is expected to triple to 152.8 million cases by 2050. Though some indications suggest that the prevalence of dementia is dropping in certain regions, such as Europe and North America, it may be possible to reduce the risk of the disease at a population level; elsewhere, the picture is less promising. Air pollution and dementia Harvard study reveals 17 threats to brain health that quietly boost your risk of stroke and dementia The researchers of the new study have found a surprising link between air pollution and dementia risk. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like How to Ease Knee Pain Without Injections or Side Effects Learn More Undo Though several studies have pointed to the possibility of an association between dementia and air pollutants, there were less evidence to prove it. The researchers at MRC carried out a systematic review and meta-analysis of existing scientific literature to examine this link further. They looked at 51 studies, which included data from 29 million participants, mostly from high-income countries. 34 papers were included in the meta-analysis: 15 originated in North America, 10 in Europe, seven in Asia, and two in Australia. They found a positive and statistically significant link between three types of air pollutants and dementia. These include: PM2.5: Particulate matter with a diameter of 2.5 microns or less. This pollutant is small enough to be inhaled deep into the lungs. The source of these particles includes vehicle emissions, power plants, industrial processes, wood-burning stoves and fireplaces, and construction dust. They form in the atmosphere as well, due to complex chemical reactions involving other pollutants such as sulphur dioxide and nitrogen oxides. These particles stay in the air for a long time and travel a long way. Nitrogen dioxide (NO2): This pollutant emerges from burning fossil fuels. It is found in vehicle exhaust, especially diesel exhaust, and industrial emissions, as well as those from gas stoves and heaters. Exposure to NO2 in high concentrations can irritate the respiratory system, worsening and inducing conditions like asthma and reducing lung function. Soot: This pollutant is formed from vehicle exhaust emissions and burning wood. It can trap heat and affect the climate. When inhaled, it can go deep into the lungs, aggravating respiratory diseases and increasing the risk of heart problems. The researchers found that every 10 micrograms per cubic meter (μg/m³) of PM2.5, increases the relative risk of dementia by 17%. In cities like Central London, PM2.5 levels on average roads have been recorded at 10 μg/m³ in 2023. When it comes to NO2, the researchers found that for every 10 μg/m3, the relative risk increased by 3%. It is worth nothing that an average roadside measurement for this pollutant in Central London in 2023 was 33 µg/m³. For each 1 μg/m³ of soot as found in PM2.5, the relative risk increased by 13%. 'Epidemiological evidence plays a crucial role in allowing us to determine whether or not air pollution increases the risk of dementia and by how much. Our work provides further evidence to support the observation that long-term exposure to outdoor air pollution is a risk factor for the onset of dementia in previously healthy adults. Tackling air pollution can deliver long-term health, social, climate, and economic benefits. It can reduce the immense burden on patients, families, and caregivers, while easing pressure on overstretched healthcare systems,' senior author Dr Haneen Khreis from the MRC Epidemiology Unit said, in a statement. How air pollution leads to dementia There are several mechanisms by which air pollution causes dementia. One of the proposed explanations is that it causes inflammation in the brain and oxidative stress, both contributing to the onset and progression of dementia. Air pollution is thought to trigger these processes through direct entry to the brain or via the same mechanisms underlying lung and cardiovascular diseases. 'Efforts to reduce exposure to these key pollutants are likely to help reduce the burden of dementia on society. Stricter limits for several pollutants are likely to be necessary, targeting major contributors such as the transport and industry sectors. Given the extent of air pollution, there is an urgent need for regional, national, and international policy interventions to combat air pollution equitably,' joint first author Clare Rogowski, also from the MRC Epidemiology Unit, said. Exposure to air pollutants was linked to a higher risk of Alzheimer's, but the effect appeared stronger for vascular dementia, which affects about 180,000 people in the UK. However, more research is required on this. 'These findings underscore the need for an interdisciplinary approach to dementia prevention. Preventing dementia is not just the responsibility of healthcare: this study strengthens the case that urban planning, transport policy, and environmental regulation all have a significant role to play,' joint first author Dr Christiaan Bredell from the University of Cambridge and North West Anglia NHS Foundation Trust added. Get the latest lifestyle updates on Times of India, along with Friendship Day wishes , messages and quotes !


Time of India
2 days ago
- Time of India
Dementia at 50: When early-onset Alzheimer's changes the course of a life
It may not necessarily begin with memory loss. When Alzheimer's comes early, in one's 40s or 50s, it often arrives without the usual signposts. You might not see someone struggling to remember names or forgetting where they live. Tired of too many ads? go ad free now Instead, the changes are quieter, harder to name. You might notice a drop in work performance. A loss of interest in things once loved. A growing struggle with language or reading. Navigating once-familiar spaces might start to feel difficult. Social withdrawal follows, subtle at first, then more obvious. This is Early-Onset Alzheimer's Disease, or EOAD. And it may not look like the Alzheimer's most people imagine. In fact, in its early stages, EOAD is often not amnestic. Many people face trouble with executive functioning, planning, prioritising, or solving problems. Others experience difficulties with spatial perception or start having trouble with language. These 'atypical' symptoms make the condition harder to spot. Many individuals are misdiagnosed with stress, anxiety, burnout, or are simply told to 'slow down. ' This delay in recognition adds another layer of distress. The emotional toll is immense in these cases. Depression and anxiety are not just common; they're expected. There is grief in real time. Because this disease strikes when people are at the height of their careers, raising children, or managing financial responsibilities. A diagnosis, when it finally comes, changes everything. Diagnosing EOAD is not straightforward. Tired of too many ads? go ad free now It often requires detailed cognitive testing, neuroimaging, and, in some cases, spinal fluid analysis. Clinicians must also rule out reversible causes like vitamin deficiencies or thyroid imbalances. Family history plays an important role too. A genetic predisposition can exist. The uncertainty, the waiting, the not knowing, it's a heavy burden for both the person and their family. Once the diagnosis is confirmed, the focus must shift, quickly and compassionately, to intervention. We now have access to more precise tools to aid diagnosis, like amyloid PET scans and biomarker-based tests, which can confirm Alzheimer's pathology. Globally, anti-amyloid therapies are beginning to show promise, though they remain limited in availability. But beyond medications, it is therapy, speech, occupational, and physiotherapy that becomes the lifeline. Because someone in their 40s or 50s still has so much life to live. Functional support is a must to preserve quality of life. Facilitating communication, mobility, and independence matters deeply, especially in this age group. Families need a lot of support to navigate through this journey. Spouses, children, siblings, they carry the weight of this diagnosis alongside their loved one. There is confusion, heartbreak, and often a sense of helplessness. But there can also be hope, especially when care is person-led and sensitive. What we've learned is that with timely diagnosis, meaningful engagement, and clinical expertise, quality of life can be enhanced. Because even when memory fades, meaning doesn't have to. By Neha Sinha, Dementia Specialist, CEO & Co-founder of Epoch Elder Care