Daily physical activity is one of the important steps to building healthy habits to lower the risk of dementia. As part of a three-part series, “Brain Health: From Awareness to Action,” Alzheimer’s Association President and CEO Joanne Pike joins “CBS Mornings” with tips on incorporating exercise into your routine as part of their “(re)think your brain” initiative. Learn more about their “6-Step Challenge” at rethinkyourbrain.org (Sponsored by the Alzheimer’s Association)

If you worry about your risk of dementia, Lauren Sprague knows your fear. Her father had a stroke when she was in high school. What followed was a long, slow descent into memory loss and dementia. He died at just 63.

“So, since I was 16 years old, pretty much every day of my life I worry, ‘Is today the day that the same thing could happen to me that happened to my dad?'” Sprague said. “It’s an incredible fear to walk around with.

“Every day of my children’s lives up until now, I’ve worried that that could be me,” she said.

Then she went to see Dr. Jonathan Rosand, who told us, “Time and again I would get the question, ‘Doctor, what can I do to take good care of my brain so that I don’t end up like my mother, my brother, my father?'”

Rosand is a neurologist at Massachusetts General Hospital in Boston. He explained to Sprague it was possible to cut the risk of dementia by making changes to daily habits, from choices about what you eat, to the amount of physical activity you get every day. “It turns out that these modifiable risk factors probably account for at least 40% of all dementia cases,” Rostand said.

A committee of experts from around the globe has concluded that about 40 to 45% of dementia cases could be prevented or delayed by addressing 14 modifiable risk factors:

• Physical inactivity
• Smoking
• Excessive alcohol consumption
• Air pollution
• Traumatic brain injury
• Hearing loss
• Untreated vision loss
• High blood pressure
• Diabetes
• Obesity
• Low education attainment
• Social isolation
• High cholesterol
• Depression 

Rostand said that it’s a very common conception that if dementia or Alzheimer’s is in one’s family, that they are doomed. “But the truth is there’s so much we can do,” he said.

The idea that exercise and diet are important is not new, of course. But what is new is a tool from Rosand and his team to help you understand exactly how much and what kind of lifestyle changes are beneficial. It starts with a simple questionnaire free to everyone online, called the Brain Care Score.

“The Brain Care Score is a tool for any of us to use in our daily lives that lists out the modifiable risk factors for dementia, stroke and depression,” Rostand said.

The healthier your habits, the higher your score. And to improve your score, you pick which habits you want to focus on changing. Rostand said, “It’s a guide to where you can go next. And in our work with patients, it really does give a choice, and a sense of freedom.”

A groundbreaking study from June 2025 found that a five-point higher Brain Care Score is associated with a 43% lower risk of developing heart disease, and a 31% lower incidence of most common cancers (including lung, colorectal, and breast cancer).

It’s evidence that what’s good for the brain is good for the rest of the body, too.

So, where to start? For Lauren Sprague and her husband, Scott, change started in the kitchen. They doubled down on greens and cut out highly-processed foods. (This added one point to her score.) They spend more time outdoors, which helps with fitness and stress relief. (That can add 2 more points.) She also takes time to sing and create, adding meaning, more stress relief, and purpose (while adding 2 more points).

Sprague said, “The Brain Care Score really gave me the prescription that I needed. And the wonderful thing about it is, it is a recommendation, but there is nuance, and it can be customized, which is wonderful.”

And Rosand is hoping this is one prescription that we all can share. He said, “The key message we want to convey with the Brain Care Score is, it is you. It is each of our viewers. It is everyone who wants to take a step forward. It’s up to you and you’re in control.”

     
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Story produced by Amol Mhatre. Editor: Emanuele Secci. 

In:

“I just know that my brain’s not right,” said Carrie Richardson, 44. “And so, I hate it. I just want it to be normal.”

At 41, Carrie developed early-onset Alzheimer’s disease. The condition is caused by rare genetic mutations that essentially guarantee a person will develop the disease. Her mother, Mary Salter, of Montgomery, Alabama, knows the toll of the disease all too well. “I’ve lost seven family members from the ages of 37 to 44,” she said … including her son, Bryan, who died last year.

Mary, Carrie, and Carrie’s daughter Hannah have been coming to the Washington University School of Medicine in St. Louis to participate in some of the world’s first clinical trials in Alzheimer’s prevention. “It’s the least I can do to help,” said Hannah. “I feel like I couldn’t live with myself if I didn’t do it.”

Dr. Randy Bateman, who leads international clinical trials at WashU Medicine, said, “Now we have a chance to change the course of the disease in a way we’ve never been able to do before.”

One reason for Bateman’s optimism: For the first time, there’s finally success treating mild Alzheimer’s with medication that removes amyloid plaques – the protein deposits that build up on the outside of nerve cells in the brain, interfering with memory and thinking. These drugs have been shown to slow cognitive decline.

“People who had the plaques removed are 30 percent better than the people who didn’t have the plaques removed,” Bateman said. “It doesn’t stop the dementia. Dementia still continues, but at a slower rate.”

The point of the trials, Bateman said, is to study what happens when treatment is started even before Alzheimer’s symptoms are evident: “If you look at the people who are treated in these trials, the people who are at the earlier stages, the earlier stage you go, the better off they do. Some of them actually have been stable. And so, what this suggests is that timing is critically important.”

Within a particular family with early-onset Alzheimer’s, symptoms usually start at about the same age, so researchers can figure out when to start treatment to try to prevent the disease. “In these people, we have near-100-percent certainty they will get Alzheimer’s disease dementia,” Bateman said. “And we know about when they’re going to get it.”

Though these rare mutations account for less than one percent of Alzheimer’s patients, the lessons learned about when to start treatment may apply to everyone. 

“A death sentence”  

Jake Heinrichs is a Broadway theater electrician from Brooklyn who carries one of the early-onset genes. The disease claimed his grandmother, uncle, father and brother, all within the same age range. “Symptoms in the 40s and, and dying in 50s,” he said.

For Heinrichs growing up, the word Alzheimer’s was “a death sentence.”

He started getting treatment in Bateman’s study in 2013. Though he’s definitely getting an antibody called lecanemab now, for the first seven years, he did not know if he was receiving an antibody or placebo. “I was at an age where I should have been showing signs,” Heinrichs said, “and I am now at an age that I should probably not even be alive.”

His wife is Broadway director Rachel Chavkin. She says over the past three years, he will occasionally repeat a question, but otherwise has shown no cognitive decline since she fell in love with him twenty years ago. “Jake is now 51, which is the age that his father was when he died,” she said.

The Trump administration’s budget cuts have stopped or delayed millions of dollars in Alzheimer’s research. The situation has already had an impact on Bateman’s trials. “It’s a precarious time,” he said. “Research is not like building a building or painting a wall where you can start and then stop for a few years and then go back and resume what you were doing. It’s much more like feeding a baby … if you stop doing that for a few weeks, it’s irrecoverable.”

“Let’s double-down on this disease”

With federal research money threatened, philanthropist Bill Gates says the effect of decreasing investment delays any breakthrough. “The data these young researchers have to consider different ideas is so much better than even five years ago,” he said. “So, this is the time where you think, wow, let’s double-down on this disease.”

That’s exactly what Gates is doing. The billionaire Microsoft co-founder is using his wealth and influence to bring together industry and government to tackle Alzheimer’s. He’s already personally invested more than $300 million. “I’m going to stay very involved in this,” he said.

At a time of such possibility, uncertainty about funding is threatening momentum. “It’s quite up in the air,” Gates said. “If you talk to researchers, they’re dealing with the uncertainty of, should they hire young people, or buy new equipment? And so, hopefully in the next several months, this gets resolved and, you know, that we can go full speed ahead.”

Gates has spent a considerable amount of his fortune to improve public health. And for him, it so happens Alzheimer’s is personal. Bill Gates Sr., an attorney and philanthropist who died five years ago at the age of 94, also had Alzheimer’s. “He was lucky enough to have 24-hour care,” said Gates. “But there was no medicine, no, nothing that could bring his cognition back.”

Gates is supporting research to improve early diagnosis, treatment, and patient enrollment in trials. And – surprise – he sees a huge role for artificial intelligence. “AI is going to impact everything we do,” he said. “The biology of the brain is so complex that AI’s ability to take large amounts of data and find meaning in that data means that this research is going to go a lot faster.”

The early-onset clinical trials are expected to continue for at least another five years involving hundreds of people at 40 sites around the world. If successful, it could usher in routine screening for Alzheimer’s with a simple blood test, just as we do now for high cholesterol and diabetes.

Could people be tested now? Bateman said, “Right now in medicine, we don’t test people without symptoms, because the treatments aren’t yet proven to work in people without symptoms.”

Finding effective treatments is a hot area of research, and may include giving cocktails of medications that target not only amyloid but other possible culprits, such as brain inflammation and a damaging nerve cell protein called tau.

Bateman said, “If this trial holds up and we can continue to demonstrate benefit year-after-year that these people are protected, then I actually think that will predict what’s gonna happen in the near future in ongoing prevention trials: That they will be positive, they will work, they will give people years of dementia-free life.”

So, Jake Heinrichs undergoes regular MRIs, physicals, memory testing, spinal taps, and PET scans to monitor his brain function, and see if he can prevent an almost-certain genetic destiny.

Four-year-old Sam Heinrichs is living proof of what can come from a belief in science – and a leap of faith.

I asked Jake, “What made you finally say, you know what, even though there’s a 50-percent chance he might get the gene, we’re going to go ahead and try to have a baby?”

“Because I’ve been part of this study, and it seems to be effective,” Jake replied. “It gave me hope that the scourge of Alzheimer’s is something that we’re not going to fear in the future. Anything could happen. But right now, I have hope.”

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READ AN EXCERPT: “The Day After Yesterday: Resilience in the Face of Dementia”
Photographer Joe Wallace has chronicled the stories of families who have lived with Alzheimer’s.

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WEB EXCLUSIVE: Watch an extended interview with Bill Gates about Alzheimer’s research (Video)

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Story produced by Jay Kernis. Editor: Jason Schmidt. 

     
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In the United States, one in three people face memory loss or dementia.

In life, you never know what cards you’ll be dealt. Linde Jacobs lost her mother in 2022, which makes being a mother to two young daughters tough. 

She’s struggled with how to properly grieve and cope. She’s struggling with making sure her daughters see strength and resilience. 

There’s also the fear. Unlike most people, Jacobs knows what cards are in her own future.

“I was speechless in that appointment,” Jacobs recalled. “I had never been delivered news like that before. It was something so shocking that I really didn’t know how to grasp it and internalize it.”

Aside from years of love, Jacobs’ mother had also given her a cruel gene that causes a condition nearly impossible to diagnose. 

“She was boundary-less”

Alison Lee was a proud mother of three girls, a successful physical therapist and a doting grandmother. But when she turned 50, life turned upside down.

“Some of her impulses would be to touch people in public, so if she saw someone, she would go pull some guy’s pants up because she said, ‘I can see your underwear.’ She was boundary-less, she didn’t realize the social norms we place on what is appropriate,” Jacobs said.  

Jacobs, a nurse herself, pounded doctors for information. She was told it was depression but she knew there was more.

Meanwhile Lee’s bizarre behavior continued. She started shoplifting, and after dodging a traffic stop she ended up in jail.

Jacobs’ sister received a letter from a fellow inmate saying, “your mom doesn’t belong here, I think she has dementia.”

“It was affirmation, first time we had somebody look into this from a third party perspective and say this is dementia,” Jacobs said.

It was a diagnosis no doctor had given. Lee hadn’t lost her memory but she had lost the mind she once had, and something clicked with Jacobs. 

Turns out, that inmate known only as “Angie” was right. That was 2018, and Jacobs still marvels at the gesture.

“The incredible kindness of a stranger to know that not only did she recognize this, but she recognized my mom as being vulnerable and then kept her sane,” Jacobs said.

Jacobs now had a clear path thanks to a to a stranger she’d never be able to thank.

But with the context of dementia, Jacobs was able to figure out a lot. She recalled that her grandmother had similar impulsive behaviors. 

It was genetic — it was the mapT mutation of frontal dementia known as FTD. It’s a disease that hits at 50, and instead of losing memories, patients often lose impulse control and self-awareness.

“Honestly, I had a lot of guilt that I was so intolerant to those symptoms when my mom would display them,” said Jacobs.

Jacobs watched her mom progress; one day Lee fell and hit her head. Because of the FTD, her brain couldn’t take the swelling and she died at 62, leaving devastation and frustration.

“I had that understanding level while she was alive, this is not her, she is not doing this to me, this is happening because this disease is causing this symptom,” Jacobs said.

But she says it was hard to separate her mom from those symptoms. Amidst the grief, she learned that she and her two sisters had the gene, too. Jacobs said immediately, her mind went to her little girls.

“Truly, that I passed it on to my daughters,” she said.

Jacobs realized that there was very little information about MapT. She could barely Google the condition that she was most certainly going to have. 

Then, she and her husband happened to see a documentary on gene editing.

“And so he just Google searched “FTD, CRISPR,” and then we came across a physician that’s based out of San Francisco, Dr. Claire Clelland,” said Jacobs.

“It’s just a matter of time”

In a busy laboratory on the other side of the country, Clelland received an email.

“I get contacted from patients, particularly gene carriers from around the world, but I remember just replying that I would try to help in the best way that I could,” she said.

That was the start of a powerful friendship. 

Jacobs set out on an advocacy journey across the nation, speaking to the nation’s top neurologists and making them better understand this tricky and brutal disease that effects 40,000 Americans, essentially putting FTD on the map. 

Clelland said Jacobs’ personal touch has fueled the process.

“And if you look at new therapies that make it through the pipeline and actually get to patients, often, they have patient supporters and champions that don’t give up even when the work gets really hard,” Clelland said.

And that hard work landed Jacobs on the front page of the New York Times. From her frustration, to her grief, to that inmate’s letter, she laid out her story for the world to see, giving her even more opportunity for revelations like the one she had in February inside a University of Minnesota research lab. 

It’s there she saw a mouse with the frontal temporal dementia mutation she has. That mouse is a symbol of hope. It’s part of promising research at the University of Minnesota.

“Linde sent me an email, she’s actually the first FTD patient I’ve ever met,” said Dr. Michael Koob, who is leading a team of researchers. 

Koob and his students are getting promising results for a treatment for people who know they have the gene.

“So, so for her, it’s just a matter of time. This is going to happen. You know, at this point, I’m fairly confident that there will be an intervention that is going to work,” said Koob.

From the mice to the microscopes, things are looking up.

WCCO followed Jacobs and her pursuit for two months. During that time, she had another breakthrough. It came at a coffee shop in River Falls, Wisconsin. 

A reunion

After years, Jacobs finally found the inmate who had sent her the initial letter about her mom. She messaged her on Facebook, and the two set up a time to meet.

When Jacobs met Angela Olson, the tears welled.

“I have no idea what the Lord is doing. I think it’s amazing that he brought our lives together. I never realized, even writing that letter, what it was doing, right? I just knew that your mom was a really great person and needed help,” said Olson.

As they marveled at the letter, they marveled at the moment.  

“I think there’s so many times in life that, like, people are brought into our lives, right, for a poor purpose, right, and a bigger purpose,” said Jacobs.

“Yeah, she’s actually the beginning of my journey with sobriety,” said Olson.

Olson knew the ropes when it came to jail; she was 20 years into her addiction. 

“Never, all these years, my whole life, I never understood how to have, actually, emotions. It’s like I was rejected in my life, betrayed by people, but yet understand how to have love or emotion, and just was so suppressed. And so then I ended up coming to Teen Challenge,” Olson said.

Now she’s seven years sober and thriving as a manager at Minnesota Adult and Teen Challenge Recovery program. She spends her days sharing her story.

Olson recalled that Lee “just kept repeating herself.” As a nurse herself, she had some experience with dementia. 

She marveled at the New York Times article with her letter in it.

“Just reading how Linde said, you know, she was easily diagnosed by inmates before any doctor diagnosed this condition. And I was just, thank you, Lord,” Olson said. “Thank you that something that I did would help this woman.”

Now, Jacobs has another partner in her fight to honor her mother and protect her daughters. She recently was invited to a gala in New York, with Anna Wintour of Vogue helping to lead fundraising.

They raised $1.9 million dollars for frontal temporal lobe dementia.

New study finds odds of dementia diagnosis increased by wildfire smoke particles

SACRAMENTO — When a wildfire rips through your community, your life and home are likely top of mind, but what about your brain health?

A new study released Monday, at the Alzheimer’s Association International Conference found that wildfire smoke is linked to heightened risk of a new dementia diagnosis.

The research was conducted in California over a span of 10 years, analyzing the health records of more than 1.2 million socioeconomically diverse Kaiser Permanente members who were 60 years or older and had not previously been diagnosed with dementia.

“What we want to do is encourage people to be aware and mitigate any risks by doing what they can to reduce them,” said Niki Rubarth, regional director for the Alzheimer’s Association of Northern California.

The study’s findings could not be more timely. The fast-moving Park Fire continues to force evacuations in Butte, Shasta, Tehama and Plumas counties. It is currently the fifth-largest wildfire in California history, burning more than 383,000 acres as of Tuesday morning.

“There’s a greater concentration of toxic chemicals in wildfire smoke. Wildfires burn everything in their path so that can be anything,” Rubarth said.

That toxic wildfire smoke can be hazardous to your brain, the study found. The report details that wildfire smoke, vehicles and factories all emit a type of air pollution called fine particulate matter or PM2.5.

Researchers revealed that the risk of dementia diagnosis due to exposure to PM2.5 in wildfire smoke was notably stronger, even with less exposure, than the risk posed by other sources of PM2.5 air pollution.

Exposure to non-wildfire PM2.5 does still come with an elevated dementia risk, but not as high as wildfire smoke.

“Previous research has found that exposure to PM2.5 is associated with dementia, but in light of our large, long-term study, it’s apparent the risk from exposure due to wildfire smoke is an even bigger concern,” said Holly Elser, M.D., Ph.D., an author of the study, in a news release on the new research. “Air pollution produced by wildfires now accounts for more than 70% of total PM2.5 exposure on poor air quality days in California. This is a real problem.”

So who is most at risk? It’s not as simple as narrowing it down to people who live in areas prone to wildfire, considering wildfire smoke travels.

“It’s lower-income people. It’s people in a lower socioeconomic level who experience the greatest threat. People who may not have control over the air filtration in their homes, if they are renters and their landlords don’t replace those air filters very frequently or maybe they are not able to replace them themselves, there is a risk there,” Rubarth said.

There is also a greater risk to people who work outside.

What should people do in their homes to protect from the wildfire smoke and its impact on their health?

“Making sure you have adequate, efficient filtration, changing your air filters or make sure they are getting changed and your filtration system is being cleaned,” Rubarth suggested.

It is also suggested that when the air quality is unhealthy, people wear an N95 mask when outdoors to reduce risk.

The Alzheimer’s Association says the number of Americans with dementia will grow

Credit scores — used to gauge a person’s ability to fulfill their financial commitments — can also be an early warning sign of cognitive decline, according to research from the New York Federal Reserve and Georgetown University. 

A person’s credit score, on average, starts to weaken in the five years ahead of a dementia diagnosis, while mortgage delinquencies start increasing three years prior, researchers found in an analysis of a nationally representative sample of credit reports and Medicare data on more than 2.4 million people spanning 2000-2017.

While not everyone in the early stage of Alzheimer’s disease and related disorders (ADRD) will fall behind on bills, for those that do, the scale of the change in delinquency is substantial. One year before diagnosis, average credit card balances in delinquency increase by more than 50% and average mortgage balances in delinquency are 11% higher, the researchers found. 

Roughly 600,000 delinquencies on some debt will occur over the next 10 years as a consequence of yet-to-be diagnosed ADRD, they estimate. 

“Our findings substantiate the possible utility of credit reporting data for facilitating early identification of those at risk for memory disorders,” the researchers state in the latest findings, which echo a 2020 study that found Medicare beneficiaries who go on to be clinically diagnosed with dementia are more likely to miss payments on bills as early as six years before diagnosis.

A progressive brain disorder that diminishes memory and cognitive skills over time, dementia affects roughly 15% of U.S. adults over 70. According to the Centers for Disease Control and Prevention, about 5.8 million people in the U.S. have Alzheimer’s disease and related dementias, including 5.6 million 65 and older.

The researchers hope to build an algorithm that will help predict who is likely to develop Alzheimer’s in the future, a tool that could be used by doctors in determining whether to recommend further screening. A predictive algorithm could prove to be a low-cost, easily scalable alternative to mass magnetic resonance imaging (MRI), for instance. 

“It is important for family and friends to realize this happens before diagnosis, to look more holistically at finances and payment decisions that older adults might be making,” Wilbert van der Klaauw, economic research adviser on household and public policy research at the New York Fed, told CBS MoneyWatch. Family members should be on the lookout for situations such as “Does this person suddenly have new credit cards?” the economist advised.

Safeguarding finances

“These types of financial difficulties can happen long before there is a diagnosis,” Carole Roan Gresenz, a professor in Georgetown University’s McCourt School of Public Policy and the School of Health, said. People should think about starting conversations to “prevent some of these financial difficulties before they happen,” she added. 

Those difficulties can include being susceptible to financial abuse, fraud or scams including identity theft or get-rich-quick schemes, according to Monica Moreno, senior director, care and support, at the Alzheimer’s Association. “Failure to address these problems or potential threats can put individuals living with dementia at great financial risk,” she stated.

The latest report “offers further evidence that challenges managing money or personal finances are common early warning signs of dementia,” Moreno said. “It is important for family members to identify those potential signs early and intervene as soon as possible,” she added.  

And, even though treatment options are limited for Alzheimer’s and other memory-related disorders, early diagnosis can mean quicker financial planning and other changes to better safeguard those afflicted and their families. 

“It can be challenging to tell how a close family member or friend is managing their personal finances because it’s often done independently, in private,” according to Moreno. “It can be even more challenging if you are not living with the person or only see the person occasionally because you may not see other disease-related warning signs that could indicate a problem.” 

Still, in the early stages of Alzheimer’s disease, people are more likely to understand the importance of the issues and suspicious activities to avoid. “If you wait, these concepts will be more difficult to comprehend as your relatives’ memories and other executive functioning skills decline,” Moreno said. 

How to discuss with loves ones

If a loved one is having difficulties managing their finances, the Alzheimer’s Association offers the following suggestions: 

• Discuss with the person how a trusted family member or friend can help with either paying bills or setting up automatic billing to avoid late payments.
• Create a separate account where you can keep a small, agreed-upon amount of money that the person can use for recreational activities, meals with friends, etc.
• Sign up to receive automatic notifications for withdrawals from bank accounts or large charges to credit cards. If you set a charge or spending limit and if the person spends more than that, the bank or credit company will let you know.
• Request electronic bank and credit card statements and watch for unusual purchases or changes in how the person typically spends money.
• Sign up for the “Do Not Call” list at donotcall.gov to protect against telemarketing calls and potential phone scams.

Nearly 188,000 dementia cases in the U.S. each year may have been caused by air pollution, researchers estimate, with bad air quality from wildfires and agriculture showing the strongest links to a person’s risk of Alzheimer’s disease and other kinds of dementia later in life. 

Published Monday in the journal JAMA Network Open, the new estimates are the latest to underscore the range of health risks scientists have long warned are being driven by air pollution. 

While studies have already linked overall bad air quality to a number of health problems, including the risk of developing dementia, the new study offers a finer-grained look at how specific causes of air pollution seem to be more strongly linked to dementia than others. 

Their findings were based on an analysis of data collected from a decades-long survey backed by the National Institutes of Health, following up with thousands of older adults around the country every two years about their health.

Researchers then combined those data with detailed air quality modeling, estimating what different people may have been exposed to in the specific areas where they lived. 

They focused on what scientists call PM 2.5 air pollution, a benchmark for very small particles — less than 2.5 micrometers wide, a fraction of the diameter of a human hair — that can be inhaled from the air. These types of particles can come from a variety of sources, including vehicle exhaust and wildfire smoke, and are linked to health effects ranging from coughing and shortness of breath to worsening asthma to an increased risk of death from heart disease.

“The environmental community has been working very hard for the past 10 to 15 years to be able to predict exposures,” said Sara Adar, associate chair of epidemiology at the University of Michigan’s School of Public Health.

Those drew on a range of data, including measurements from the Environmental Protection Agency and details about nearby factors that could affect their air quality. 

“They model all sources at once. Coal-fired power plants, agriculture, wildfires, traffic, all these different emission sources, and then they turn off the source in the model one at a time. And then they can see the difference in what levels are there with the emissions sources, and what are there without them,” said Adar.

Their modeling had found the higher risk even after adjusting for a range of potential factors that could have led to muddled results, like sex, race and ethnicity, educational status and wealth. 

They also were able to adjust for whether people previously lived in urban or rural areas. 

While they also had information for where people moved during the survey, Adar acknowledged they did not have enough data to model every exposure or check for every difference throughout the course of their life — like where people were born — which might have impacted their results.

“Dementia takes a long time to develop. It’s not something that might be, ‘oh you’ve got a bad exposure last week, and now you have dementia.’ It’s more likely to build up over a lifetime,” said Adar. 

Beyond the direct emissions from wildfires and agriculture, Adar noted their analysis was able to take into account other kinds of air pollution that can also be traced back to these sources.

In addition to the smoke emitted from wildfires, other toxic molecules can be carried with the smoke as they burn through communities. Farming can also worsen air pollution, resulting from the ammonia that are released by sources like manure and fertilizer.

“Farms will release a lot of ammonia gas, and then in the air with the sunlight and other pollutants out there, they’ll react to make particles, and those particles are what we see are likely toxins for the brain,” said Adar.

Adar and Boya Zhang, also a researcher at the school, say they hope their new findings could drive more targeted interventions to address this dementia risk. 

“Unlike many other common risk factors for dementia (eg, hypertension, stroke, and diabetes), exposures to air pollution can be modified at the population level, making it a prime target for large-scale prevention efforts,” the study’s authors wrote.

The Food and Drug Administration on Thursday gave its approval to Leqembi, a drug designed to slow the progression of Alzheimer’s disease. Leqembi is not considered a cure for Alzheimer’s, but will be covered by Medicare. Dr. Jon LaPook has more.

More than six million older Americans are living with dementia. A new study suggests that hearing aids may help slow cognitive decline. CBS News chief medical correspondent Dr. Jon LaPook takes a look.