(Left to right) Vickie Naylor, Bernadine Clay, and Donna Maxey read a memory prompt as they take part in the Sharing History through Active Reminiscence and Photo-Imagery (SHARP) study, September 20, 2017.
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.
The author's son Chris, at two years old in the summer of 1980, before his 4th DPT shot.
[Editor's Note: This opinion essay is in response to our current Big Question, which we posed to experts with different viewpoints: "Where should society draw the line between requiring vaccinations for children and allowing parental freedom of choice?"]
Our children are the future. The survival of humanity is advanced by the biological imperative that mothers and fathers want and need to protect their children and other children from being harmed for any reason.
Science is not perfect, doctors are not infallible, and medical interventions come with risks.
In the 21st century, consensus science considers vaccination to be one of the greatest inventions in the history of medicine and the greatest achievement of public health programs. The national vaccination rate for U.S. kindergarten children is 94 percent and most children today receive 69 doses of 16 federally recommended vaccines. However, public health is not simply measured by high vaccination rates and absence of infectious disease, which is evidenced by the chronic inflammatory disease and disability epidemic threatening to bankrupt the U.S. health care system.
Science is not perfect, doctors are not infallible, and medical interventions come with risks, which is why parents have the power to exercise informed consent to medical risk taking on behalf of their minor children.
As a young mother, I learned that vaccine risks are 100 percent for some children because, while we are all born equal under the law, we are not born all the same. Each one of us enters this world with different genes, a unique microbiome and epigenetic influences that affect how we respond to the environments in which we live. We do not all respond the same way to infectious diseases or to pharmaceutical products like vaccines.
Few parents were aware of vaccine side effects in 1980, when my bright, healthy two-and-a-half year-old son, Chris, suffered a convulsion, collapse, and state of unconsciousness (encephalopathy) within hours of his fourth DPT shot, and then regressed physically, mentally and emotionally and became a totally different child. Chris was eventually diagnosed with multiple learning disabilities and confined to a special education classroom throughout his public school education, but he and I both know his vaccine reaction could have been much worse. Today, Chris is an independent adult but many survivors of brain injury are not.
Barbara Loe Fisher and her son, Chris, in December 1981 after his fourth DPT shot.
(Courtesy Fisher)
The public conversation about several hundred cases of measles reported in the U.S. this year is focused on whether every parent has a social obligation to vaccinate every child to maintain "community immunity," but vaccine failures are rarely discussed. Emerging science reveals that there are differences in naturally and vaccine acquired immunity, and both vaccinated and unvaccinated children and adults transmit infections, sometimes with few or no symptoms.
Nearly 40 percent of cases reported in the 2015 U.S. measles outbreak occurred in recently vaccinated individuals who developed vaccine reactions that appeared indistinguishable from measles. Outbreaks of pertussis (whooping cough) in highly vaccinated child populations have been traced to waning immunity and evolution of the B. pertussis microbe to evade the vaccines. Influenza vaccine effectiveness was less than 50 percent in 11 of the past 15 flu seasons.
Vaccine policymakers recognize that children with severe combined immune deficiency or those undergoing chemotherapy or organ transplants are at increased risk for complications of infectious diseases and vaccines. However, there is no recognition of the risks to healthy infants and children with unidentified susceptibility to vaccine reactions, including children whose health suddenly deteriorates without explanation after vaccination. Medical care is being denied to children and adults in the U.S. if even one government recommended vaccination is declined, regardless of health or vaccine reaction history.
When parents question the risks and failures of a commercial pharmaceutical product being mandated for every child, the answer is not more force but better science and respect for the informed consent ethic.
The social contract we have with each other when we live in communities, whether we belong to the majority or a minority, is to care about and protect every individual living in the community. One-size-fits-all vaccine policies and laws, which fail to respect biodiversity and force everyone to be treated the same, place an unequal risk burden on a minority of unidentified individuals unable to survive vaccination without being harmed.
A law that requires certain minorities to bear a greater risk of injury or sacrifice their lives in service to the majority is not just or moral.
Between 1991 and 2013, the Institute of Medicine (IOM) published reports documenting that vaccines can cause brain inflammation and other serious reactions, injuries and death. A 2012 IOM report acknowledged that there are genetic, biological, and environmental risk factors that make some individuals more susceptible to adverse responses to vaccines but often doctors cannot identify who they are because of gaps in vaccine science. Congress acknowledged this fact a quarter century earlier in the 1986 National Childhood Vaccine Injury Act, which created a federal vaccine injury compensation program alternative to a lawsuit that has awarded more than $4 billion to vaccine-injured children and adults.
We give up the human right to autonomy and informed consent at our peril, no matter where or in what century we live.
Vaccine manufacturers and administrators have liability protection, yet today almost no health condition qualifies for a medical vaccine exemption under government guidelines. Now, there is a global call by consensus science advocates for elimination of all personal belief vaccine exemptions and censorship of books and public conversations that criticize vaccine safety or government vaccine policy. Some are calling for quarantine of all who refuse vaccinations and criminal prosecution, fines and imprisonment of parents with unvaccinated children, as well as punishment of doctors who depart from government policy.
There is no civil liberty more fundamentally a natural, inalienable right than exercising freedom of thought and conscience when deciding when and for what reason we are willing to risk our life or our child's life. That is why voluntary, informed consent to medical risk-taking has been defined as a human right governing the ethical practice of modern medicine.
In his first Presidential inaugural address, Thomas Jefferson warned:
"All, too, will bear in mind this sacred principle, that though the will of the majority is in all cases to prevail, that will to be rightful must be reasonable; that the minority posses their equal rights, which equal law must protect, and to violate would be oppression."
The seminal 1905 U.S. Supreme Court decision, Jacobson v. Massachusetts, affirmed the constitutional authority of states to enact mandatory smallpox vaccination laws. However, the justices made it clear that implementation of a vaccination law should not become "cruel and inhuman to the last degree." They warned, "All laws, this court has said, should receive a sensible construction. General terms should be so limited in their application as not to lead to injustice, oppression, or an absurd consequence. It will always, therefore, be presumed that the legislature intended exceptions to its language, which would avoid results of this character."
Mothers and fathers, who know and love their children better than anyone else, depend upon sound science and compassionate public health policies to help them protect their own and other children from harm. If individuals susceptible to vaccine injury cannot be reliably identified, the accuracy of vaccine benefit and risk calculations must be reexamined. Yet, consensus science and medicine around vaccination discourages research into the biological mechanisms of vaccine injury and death and identification of individual risk factors to better inform public health policy.
A critic of consensus science, physician and author Michael Crichton said, "Let's be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Period."
Condoning elimination of civil liberties, including freedom of speech and the right to dissent guaranteed under the First Amendment of the U.S. Constitution, to enforce vaccination creates a slippery slope. Coercion, punishment and censorship will destroy, not instill, public trust in the integrity of medical practice and public health laws.
There are more than a dozen new vaccines being fast tracked to market by industry and governments. Who in society should be given the power to force all children to use every one of them without parental consent regardless of how small or great the risk?
We give up the human right to autonomy and informed consent at our peril, no matter where or in what century we live. Just and compassionate public health laws that protect parental and human rights will include flexible medical, religious and conscientious belief vaccine exemptions to affirm the informed consent ethic and prevent discrimination against vulnerable minorities.
[Editor's Note: Read the opposite viewpoint here.]
