Alzheimer’s prevention may be less about new drugs, more about income, zip code and education
That your risk of Alzheimer’s disease depends on your salary, what you ate as a child, or the block where you live may seem implausible. But researchers are discovering that social determinants of health (SDOH) play an outsized role in Alzheimer’s disease and related dementias, possibly more than age, and new strategies are emerging for how to address these factors.
At the 2022 Alzheimer’s Association International Conference, a series of presentations offered evidence that a string of socioeconomic factors—such as employment status, social support networks, education and home ownership—significantly affected dementia risk, even when adjusting data for genetic risk. What’s more, memory declined more rapidly in people who earned lower wages and slower in people who had parents of higher socioeconomic status.
In 2020, a first-of-its kind study in JAMA linked Alzheimer’s incidence to “neighborhood disadvantage,” which is based on SDOH indicators. Through autopsies, researchers analyzed brain tissue markers related to Alzheimer’s and found an association with these indicators. In 2022, Ryan Powell, the lead author of that study, published further findings that neighborhood disadvantage was connected with having more neurofibrillary tangles and amyloid plaques, the main pathological features of Alzheimer's disease.
As of yet, little is known about the biological processes behind this, says Powell, director of data science at the Center for Health Disparities Research at the University of Wisconsin School of Medicine and Public Health. “We know the association but not the direct causal pathway.”
The corroborative findings keep coming. In a Nature study published a few months after Powell’s study, every social determinant investigated affected Alzheimer’s risk except for marital status. The links were highest for income, education, and occupational status.
Clinical trials on new Alzheimer’s medications get all the headlines but preventing dementia through policy and public health interventions should not be underestimated.
The potential for prevention is significant. One in three older adults dies with Alzheimer's or another dementia—more than breast and prostate cancers combined. Further, a 2020 report from the Lancet Commission determined that about 40 percent of dementia cases could theoretically be prevented or delayed by managing the risk factors that people can modify.
Take inactivity. Older adults who took 9,800 steps daily were half as likely to develop dementia over the next 7 years, in a 2022 JAMA study. Hearing loss, another risk factor that can be managed, accounts for about 9 percent of dementia cases.
Clinical trials on new Alzheimer’s medications get all the headlines but preventing dementia through policy and public health interventions should not be underestimated. Simply slowing the course of Alzheimer’s or delaying its onset by five years would cut the incidence in half, according to the Global Council on Brain Health.
Minorities Hit the Hardest
The World Health Organization defines SDOH as “conditions in which people are born, work, live, and age, and the wider set of forces and systems shaping the conditions of daily life.”
Anyone who exists on processed food, smokes cigarettes, or skimps on sleep has heightened risks for dementia. But minority groups get hit harder. Older Black Americans are twice as likely to have Alzheimer’s or another form of dementia as white Americans; older Hispanics are about one and a half times more likely.
This is due in part to higher rates of diabetes, obesity, and high blood pressure within these communities. These diseases are linked to Alzheimer’s, and SDOH factors multiply the risks. Blacks and Hispanics earn less income on average than white people. This means they are more likely to live in neighborhoods with limited access to healthy food, medical care, and good schools, and suffer greater exposure to noise (which impairs hearing) and air pollution—additional risk factors for dementia.
Related Reading: The Toxic Effects of Noise and What We're Not Doing About it
Plus, when Black people are diagnosed with dementia, their cognitive impairment and neuropsychiatric symptom are more advanced than in white patients. Why? Some African-Americans delay seeing a doctor because of perceived discrimination and a sense they will not be heard, says Carl V. Hill, chief diversity, equity, and inclusion officer at the Alzheimer’s Association.
Misinformation about dementia is another issue in Black communities. The thinking is that Alzheimer’s is genetic or age-related, not realizing that diet and physical activity can improve brain health, Hill says.
African Americans are severely underrepresented in clinical trials for Alzheimer’s, too. So, researchers miss the opportunity to learn more about health disparities. “It’s a bioethical issue,” Hill says. “The people most likely to have Alzheimer’s aren’t included in the trials.”
The Cure: Systemic Change
People think of lifestyle as a choice but there are limitations, says Muniza Anum Majoka, a geriatric psychiatrist and assistant professor of psychiatry at Yale University, who published an overview of SDOH factors that impact dementia. “For a lot of people, those choices [to improve brain health] are not available,” she says. If you don’t live in a safe neighborhood, for example, walking for exercise is not an option.
Hill wants to see the focus of prevention shift from individual behavior change to ensuring everyone has access to the same resources. Advice about healthy eating only goes so far if someone lives in a food desert. Systemic change also means increasing the number of minority physicians and recruiting minorities in clinical drug trials so studies will be relevant to these communities, Hill says.
Based on SDOH impact research, raising education levels has the most potential to prevent dementia. One theory is that highly educated people have a greater brain reserve that enables them to tolerate pathological changes in the brain, thus delaying dementia, says Majoka. Being curious, learning new things and problem-solving also contribute to brain health, she adds. Plus, having more education may be associated with higher socioeconomic status, more access to accurate information and healthier lifestyle choices.
New Strategies
The chasm between what researchers know about brain health and how the knowledge is being applied is huge. “There’s an explosion of interest in this area. We’re just in the first steps,” says Powell. One day, he predicts that physicians will manage Alzheimer’s through precision medicine customized to the patient’s specific risk factors and needs.
Raina Croff, assistant professor of neurology at Oregon Health & Science University School of Medicine, created the SHARP (Sharing History through Active Reminiscence and Photo-imagery) walking program to forestall memory loss in African Americans with mild cognitive impairment or early dementia.
Participants and their caregivers walk in historically black neighborhoods three times a week over six months. A smart tablet provides information about “Memory Markers” they pass, such as the route of a civil rights march. People celebrate their community and culture while “brain health is running in the background,” Croff says.
Photos and memory prompts engage participants in the SHARP program.
OHSU/Kristyna Wentz-Graff
The project began in 2015 as a pilot study in Croff’s hometown of Portland, Ore., expanded to Seattle, and will soon start in Oakland, Calif. “Walking is good for slowing [brain] decline,” she says. A post-study assessment of 40 participants in 2017 showed that half had higher cognitive scores after the program; 78 percent had lower blood pressure; and 44 percent lost weight. Those with mild cognitive impairment showed the most gains. The walkers also reported improved mood and energy along with increased involvement in other activities.
It’s never too late to reap the benefits of working your brain and being socially engaged, Majoka says.
In Milwaukee, the Wisconsin Alzheimer’s Institute launched the The Amazing Grace Chorus® to stave off cognitive decline in seniors. People in early stages of Alzheimer’s practice and perform six concerts each year. The activity provides opportunities for social engagement, mental stimulation, and a support network. Among the benefits, 55 percent reported better communication at home and nearly half of participants said they got involved with more activities after participating in the chorus.
Private companies are offering intervention services to healthcare providers and insurers to manage SDOH, too. One such service, MyHello, makes calls to at-risk people to assess their needs—be it food, transportation or simply a friendly voice. Having a social support network is critical for seniors, says Majoka, noting there was a steep decline in cognitive function among isolated elders during Covid lockdowns.
About 1 in 9 Americans age 65 or older live with Alzheimer’s today. With a surge in people with the disease predicted, public health professionals have to think more broadly about resource targets and effective intervention points, Powell says.
Beyond breakthrough pills, that is. Like Dorothy in Kansas discovering happiness was always in her own backyard, we are beginning to learn that preventing Alzheimer’s is in our reach if only we recognized it.
This Startup Uses Dust to Fight Sweatshops
"Dust thou art, and unto dust shalt thou return." Whoever wrote that famous line probably didn't realize that dust actually contains a secret weapon.
"We have developed the capability to turn dust into data that can be used to trace problems in the supply chain."
Far from being a collection of mere inanimate particles, dust is now recognized as a powerful tool filled with living sensors. Studying those sensors can reveal an object's location history, which can help brands fight unethical manufacturing.
"We have developed the capability to turn dust into data that can be used to trace problems in the supply chain," explains Jessica Green, the CEO of Phylagen, a San-Francisco-based company that she co-founded in 2014.
So how does the technology work?
Dust gathers everywhere—on our bodies, on objects—and that dust contains microbes like bacteria and viruses. Just as we humans have our own unique microbiomes, research has shown that physical locations have their own identifiable patterns of microbes as well. Visiting a place means you may pick up its microbial fingerprint in the dust that settles on you. The DNA of those microbes can later be sequenced in a lab and matched back to the place of origin.
"Your environment is constantly imprinted on you and vice versa," says Justin Gallivan, the director of the Biotechnology Office at DARPA, the research and defense arm of the Pentagon, which is funding Phylagen. "If we have a microbial map of the world," he posits, "can we infer an object's transit history?"
So far, Phylagen has shown that it's possible to identify where a ship came from based on the unique microbial populations it picked up at different naval ports. In another experiment, the sampling technology allowed researchers to determine where a person had walked within 1 kilometer in San Francisco, because of the microbes picked up by their shoes.
Data scientist Roxana Hickey, left, and CEO Jessica Green of Phylagen.
One application of this technology is to help companies that make products abroad. Such companies are very interested in determining exactly where their products are coming from, especially if foreign subcontractors are involved.
"In retail and apparel, often the facilities performing the subcontracting are not up to the same code that the brands require their suppliers to be, so there could be poor working conditions," says Roxana Hickey, a data scientist at Phylagen. "A supplier might use a subcontractor to save on the bottom line, but unethical practices are very damaging to the brand."
Before this technology was developed, brands sometimes faced a challenge figuring out what was going on in their supply chain. But now a product can be tested upon arrival in the States; its microbial signature can theoretically be analyzed and matched against a reference database to help determine if its DNA pattern matches that of the place where the product was purported to have been made.
Phylagen declined to elaborate further about how their process works, such as how they are building a database of reference samples, and how consistent a microbial population remains across a given location.
As the technology grows more robust, though, one could imagine numerous other applications, like in police work and forensics. But today, Phylagen is solely focused on helping commercial entities bring greater transparency to their operations so they can root out unauthorized subcontracting.
Then those unethical suppliers can – shall we say – bite the dust.
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.
Surfing for Science: A Fin Sensor Is Making Waves
For David Walden, a Southern Californian, surfing is a lifestyle, not a hobby. The 38-year-old works nights at a seafood restaurant to leave his mornings free for surfing.
While the surfers are doing what they love, they are also collecting information that is helping scientists better understand the ocean.
"Once you fall in love with the ocean, you need it like a daily cleanse or refresher," he says. "The positive mental and physical effects of the ocean, the endorphins and dopamine, keep you addicted in a good way."
Given his dedication to surfing, Walden was delighted when he became one of more than 200 surfers last year to test Smartfin, a 5-1/2-inch surfboard fin that contains a circuit board, a rechargeable battery, a GPS device, a sensor that captures temperature to one-hundredth of a degree, and a motion sensor that tracks the movement of the waves. While Walden and his fellow surfers are doing what they love, they are also collecting information that is helping scientists better understand the health of the near-shore ocean and how its chemistry is shifting due to climate change.
"I'm excited to be a part of it," Walden says. "I like to tell people I surf for science."
Back on shore, the surfers download the Smartfin data via a smartphone app so they can be accessed by scientists and other interested parties. (You can see where Smartfin surfers go at this interactive map.)
By putting sensors directly onto surfboards, oceanographers can collect data to help them better understand the global-warming related changes occurring in coastal oceans in temperature, salinity, and pH, all properties that have huge implications for the species that live in near-shore ecosystems.
There is much unknown about coastal waters because it's so difficult to obtain meaningful measurements. Traditional methods to monitor the close shore, such as bottle samples and buoys, are time consuming and expensive and tend to get damaged by the surf.
The Smartfin is the brainchild of Dr. Andy Stern, a retired neurologist. He and his brother-in-law, sculptor and filmmaker Todd McGrain, run The Lost Bird Project, a nonprofit devoted to raising awareness about climate change and other environmental issues. Stern brought his super fin idea to engineer Benjamin Thompson, who spent several years creating a prototype in his garage workshop. Smartfin was further developed by scientists at the Scripps Institution of Oceanography at the University of California at San Diego.
"The big challenge was to make a sensor small enough to fit in the fin but still produce good measurements," says Andreas Andersson, an associate professor of geoscience research at Scripps.
The Surfrider Foundation, a surfer-led nonprofit environmental organization, came aboard two years ago to distribute the Smartfin to its San Diego members.
Smartfin has also made a splash with scientists at the University of the Sunshine Coast in Queensland on the eastern coast of Australia. They are using the fin's temperature sensor to better understand how climate change is affecting the movement and distribution of marine life. And at the Plymouth Marine Laboratory in Plymouth, United Kingdom, the Smartfin's precise temperature readings of the near-shore ocean's surface are being used to improve the accuracy of satellites that monitor the ocean from hundreds of miles away.
"It's hard to talk about climate change in a way that's not boring or gloomy, but there's nothing gloomy or depressing about surfers and Smartfin."
"The hope is that Smartfin will improve the satellite measurements, which could improve the retrieval of temperature data around the world," says Dr. Phil Bresnahan, Smartfin's lead engineer at Scripps. In the future, the fin will include sensors to measure pH, chlorophyll (algae), dissolved oxygen, and turbidity (water clarity).
Stern envisions a time when thousands of surfers, paddle boarders, and other water enthusiasts worldwide will have Smartfins and be downloading data for scientists and environmentalists. Right now, there are approximately 70 surfers in the San Diego area using Smartfin and an additional 30 globally.
Scientists have plenty of evidence that global warming is largely caused by humans. Now they are trying to figure out what the long-term effects of climate change may be. For example, scientists are trying to predict which sections of coral reef, which house 25 percent of marine species, are most vulnerable so interventions can be developed to save them. Because of its small size, Smartfin is ideal to measure temperature changes in coral reefs.
Smartfin was also intended to be an educational tool. "It's a great way to start a different conversation about climate change," says Stern. "It's hard to talk about climate change in a way that's not boring or gloomy, but there's nothing gloomy or depressing about surfers and Smartfin. People want to hear more."
Turning surfers into citizen scientists makes perfect sense, says David Pasquini, 35, a longtime surfer who works for the British Consulate General's office in Oceanside, Calif. "Anyone who spends a lot of time in the ocean is aware of the changes happening in the ecosystem, the climate," says Pasquini. "Everyone asks, 'What can I do?'" Surfing with Smartfin, Pasquini feels like he is giving back.
"I know the data will be analyzed and eventually used to make a policy that helps with climate change. That's a great feeling--just by surfing, doing something you love, you're contributing."