(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.
How AI changes things
Sure, you would reply, but AI changes everything. With artificial intelligence, the machine itself will develop some sort of autonomy, however ill-defined. It will have a will of its own. And this will, if it reflects anything that seems human, will not be benevolent. With AI, the claim goes, the machine will somehow know what it must do to get rid of us. It will threaten us as a species.
Well, this fear is also not new. Mary Shelley wrote Frankenstein in 1818 to warn us of what science could do if it served the wrong calling. In the case of her novel, Dr. Frankenstein’s call was to win the battle against death — to reverse the course of nature. Granted, any cure of an illness interferes with the normal workings of nature, yet we are justly proud of having developed cures for our ailments, prolonging life and increasing its quality. Science can achieve nothing more noble. What messes things up is when the pursuit of good is confused with that of power. In this distorted scale, the more powerful the better. The ultimate goal is to be as powerful as gods — masters of time, of life and death.
Should countries create a World Mind Organization that controls the technologies that develop AI?
Back to AI, there is no doubt the technology will help us tremendously. We will have better medical diagnostics, better traffic control, better bridge designs, and better pedagogical animations to teach in the classroom and virtually. But we will also have better winnings in the stock market, better war strategies, and better soldiers and remote ways of killing. This grants real power to those who control the best technologies. It increases the take of the winners of wars — those fought with weapons, and those fought with money.
A story as old as civilization
The question is how to move forward. This is where things get interesting and complicated. We hear over and over again that there is an urgent need for safeguards, for controls and legislation to deal with the AI revolution. Great. But if these machines are essentially functioning in a semi-black box of self-teaching neural nets, how exactly are we going to make safeguards that are sure to remain effective? How are we to ensure that the AI, with its unlimited ability to gather data, will not come up with new ways to bypass our safeguards, the same way that people break into safes?
The second question is that of global control. As I wrote before, overseeing new technology is complex. Should countries create a World Mind Organization that controls the technologies that develop AI? If so, how do we organize this planet-wide governing board? Who should be a part of its governing structure? What mechanisms will ensure that governments and private companies do not secretly break the rules, especially when to do so would put the most advanced weapons in the hands of the rule breakers? They will need those, after all, if other actors break the rules as well.
As before, the countries with the best scientists and engineers will have a great advantage. A new international détente will emerge in the molds of the nuclear détente of the Cold War. Again, we will fear destructive technology falling into the wrong hands. This can happen easily. AI machines will not need to be built at an industrial scale, as nuclear capabilities were, and AI-based terrorism will be a force to reckon with.
So here we are, afraid of our own technology all over again.
What is missing from this picture? It continues to illustrate the same destructive pattern of greed and power that has defined so much of our civilization. The failure it shows is moral, and only we can change it. We define civilization by the accumulation of wealth, and this worldview is killing us. The project of civilization we invented has become self-cannibalizing. As long as we do not see this, and we keep on following the same route we have trodden for the past 10,000 years, it will be very hard to legislate the technology to come and to ensure such legislation is followed. Unless, of course, AI helps us become better humans, perhaps by teaching us how stupid we have been for so long. This sounds far-fetched, given who this AI will be serving. But one can always hope.
This article originally appeared on Big Think, home of the brightest minds and biggest ideas of all time.
Jamie Metzl, author of Hacking Darwin, shares his views with Leaps.org on the future of genetics, tech, healthcare and more.
In Hacking Darwin, you describe how we may modify the human body with CRISPR technologies, initially to obtain unsurpassed sports performance and then to enhance other human characteristics. What would such power over human biology mean for the future of our civilization?
After nearly four billion years of evolution, our one species suddenly has the increasing ability to read, write, and hack the code of life. This will have massive implications across the board, including in human health and reproduction, plant and animal agriculture, energy and advanced materials, and data storage and computing, just to name a few. My book Hacking Darwin: Genetic Engineering and the Future of Humanity primarly explored how we are currently deploying and will increasingly use our capabilities to transform human life in novel ways. My next book, The Great Biohack: Recasting Life in an Age of Revolutionary Technology, coming out in May 2024, will examine the broader implications for all of life on Earth.
We humans will, over time, use these technologies on ourselves to solve problems and eventually to enhance our capabilities. We need to be extremely conservative, cautious, and careful in doing so, but doing so will almost certainly be part of our future as a species.
In electronics, Moore's law is an established theory that computing power doubles every 18 months. Is there any parallel to be drawn with genetic technologies?
The increase in speed and decrease in costs of genome sequencing have progressed far faster than Moore’s law. It took thirteen years and cost about a billion dollars to sequence the first human genome. Today it takes just a few hours and can cost as little as a hundred dollars to do a far better job. In 2012, Jennifer Doudna and Emmanuel Charpentier published the basic science paper outlining the CRISPR-cas9 genome editing tool that would eventually win them the Nobel prize. Only six years later, the first CRISPR babies were born in China. If it feels like technology is moving ever-faster, that’s because it is.
Let's turn to the topic of aging. Do you think that the field of genetics will advance fast enough to eventually increase maximal lifespan for a child born this year? How about for a person who is currently age 50?
The science of aging is definitely real, but that doesn’t mean we will live forever. Aging is a biological process subject to human manipulation. Decades of animal research shows that. This does not mean we will live forever, but it does me we will be able to do more to expand our healthspans, the period of our lives where we are able to live most vigorously.
The first thing we need to do is make sure everyone on earth has access to the resources necessary to live up to their potential. I live in New York City, and I can take a ten minute subway ride to a neighborhood where the average lifespan is over a decade shorter than in mine. This is true within societies and between countries as well. Secondly, we all can live more like people in the Blue Zones, parts of the world where people live longer, on average, than the rest of us. They get regular exercise, eat healthy foods, have strong social connections, etc. Finally, we will all benefit, over time, from more scientific interventions to extend our healthspan. This may include small molecule drugs like metformin, rapamycin, and NAD+ boosters, blood serum infusions, and many other things.
Science fiction has depicted a future where we will never get sick again, stay young longer or become immortal. Assuming that any of this is remotely possible, should we be afraid of such changes, even if they seem positive in some regards, because we can’t understand the full implications at this point?
Not all of these promises will be realized in full, but we will use these technologies to help us live healthier, longer lives. We will never become immortal becasue nothing lasts forever. We will always get sick, even if the balance of diseases we face shifts over time, as it has always done. It is healthy, and absolutely necessary, that we feel both hope and fear about this future. If we only feel hope, we will blind ourselves to the very real potential downsides. If we only feel fear, we will deny ourselves the very meaningful benefits these technologies have the potential to provide.
A fascinating chapter in Hacking Darwin is entitled The End of Sex. And you see that as a good thing?
We humans will always be a sexually reproducing species, it’s just that we’ll reproduce increasingly less through the physical act of sex. We’re already seeing this with IVF. As the benefits of technology assisted reproduction increase relative to reproduction through the act of sex, many people will come to see assisted reproduction as a better way to reduce risk and, over time, possibly increase benefits. We’ll still have sex for all the other wonderful reasons we have it today, just less for reproduction. There will always be a critical place in our world for Italian romantics!
What are dangers of genetic hackers, perhaps especially if everyone’s DNA is eventually transcribed for medical purposes and available on the internet and in the cloud?
The sky is really the limit for how we can use gentic technologies to do things we may want, and the sky is also the limit for potential harms. It’s quite easy to imagine scenarios in which malevolent actors create synthetic pathogens designed to wreak havoc, or where people steal and abuse other people’s genetic information. It wouldn’t even need to be malevolent actors. Even well-intentioned researchers making unintended mistakes could cause real harm, as we may have seen with COVID-19 if, as appears likely to me, the pandemic stems for a research related incident]. That’s why we need strong governance and regulatory systems to optimize benefits and minimize potential harms. I was honored to have served on the World Health Organization Expert Advisory Committee on Human Genome Editing, were we developed a proposed framework for how this might best be achieved.
You foresee the equivalent of a genetic arms race between the world's most powerful countries. In what sense are genetic technologies similar to weapons?
Genetic technologies could be used to create incredibly powerful bioweapons or to build gene drives with the potential to crash entire ecosystems. That’s why thoughtful regulation is in order. Because the benefits of mastering and deploying these technologies are so great, there’s also a real danger of a genetics arms race. This could be extremely dangerous and will need to be prevented.
In your book, you express concern that states lacking Western conceptions of human rights are especially prone to misusing the science of genetics. Does this same concern apply to private companies? How much can we trust them to control and wield these technologies?
This is a conversation about science and technology but it’s really a conversation about values. If we don’t agree on what core values should be promoted, it will be nearly impossible to agree on what actions do and do not make sense. We need norms, laws, and values frameworks that apply to everyone, including governments, corporations, researchers, healthcare providers, DiY bio hobbyists, and everyone else.
We have co-evolved with our technology for a very long time. Many of our deepest beliefs have formed in that context and will continue to do so. But as we take for ourselves the powers we have attributed to our various gods, many of these beliefs will be challenged. We can not and must not jettison our beliefs in the face of technology, and must instead make sure our most cherished values guide the application of our most powerful technologies.
A conversation on international norms is in full swing in the field of AI, prompted by the release of ChatGPT4 earlier this year. Are there ways in which it’s inefficient, shortsighted or otherwise problematic for these discussions on gene technologies, AI and other advances to be occurring in silos? In addition to more specific guidelines, is there something to be gained from developing a universal set of norms and values that applies more broadly to all innovation?
AI is yet another technology where the potential to do great good is tied to the potential to inflict signifcant harm. It makes no sense that we tend to treat each technology on its own rather than looking at the entire category of challenges. For sure, we need to very rapidly ramp up our efforts with regard to AI norm-setting, regulations, and governance at all levels. But just doing that will be kind of like generating a flu vaccine for each individual flu strain. Far better to build a universal flu vaccine addressing common elements of all flu viruses of concern.
That’s why we also need to be far more deliberate in both building a global operating systems based around the mutual responsibilities of our global interdependence and, under that umbrella, a broader system for helping us govern and regulate revolutionary technologies. Such a process might begin with a large international conference, the equivalent of Rio 1992 for climate change, but then quickly work to establish and share best practices, help build parallel institutions in all countries so people and governamts can talk with each other, and do everything possible to maximize benefits and minimize risks at all levels in an ongoing and dynamic way.
At what point might genetic enhancements lead to a reclassfication of modified humans as another species?
We’ll still all be fellow humans for a very, very long time. We already have lots of variation between us. That is the essence of biology. Will some humans, at some point in the future, leave Earth and spend generations elsewhere? I believe so. In those new environments, humans will evolve, over time, differently than those if us who remain on this planet? This may sound like science fiction, but the sci-fi future is coming at us faster than most people realize.
Is the concept of human being changing?
Yes. It always has and always will.
Another big question raised in your book: what limits should we impose on the freedom to manipulate genetics?
Different societies will come to different conclusion on this critical question. I am sympathetic to the argument that people should have lots of say over their own bodies, which why I support abortion rights even though I recognize that an abortion can be a violent procedure. But it would be insane and self-defeating to say that individuals have an unlimited right to manipulate their own or their future children’s heritable genetics. The future of human life is all of our concern and must be regulated, albeit wisely.
In some cases, such as when we have the ability to prevent a deadly genetic disroder, it might be highly ethical to manipulate other human beings. In other circumstances, the genetic engineering of humans might be highly unethical. The key point is to avoid asking this question in a binary manner. We need to weigh the costs and benefits of each type of intervention. We need societal and global infrastrucutres to do that well. We don’t yet have those but we need them badly.
Can you tell us more about your next book?
The Great Biohack: Recasting Lifee in an Age of Revolutionary Technology, will come out in May 2024. It explores what the intersecting AI, genetics, and biotechnology revolutions will mean for the future of life on earth, including our healthcare, agriculture, industry, computing, and everything else. We are at a transitional moment for life on earth, equivalent to the dawn of agriculture, electricity, and industrialization. The key differentiator between better and worse outcomes is what we do today, at this early stage of this new transformation. The book describes what’s happening, what’s at stake, and what we each and all can and, frankly, must do to build the type of future we’d like to inhabit.
You’ve been a leader of international efforts calling for a full investigation into COVID-19 origins and are the founder of the global movement OneShared.World. What problem are you trying to solve through OneShared.World?
The biggest challenge we face today is the mismatch between the nature of our biggest problems, global and common, and the absence of a sufficient framework for addressing that entire category of challenges. The totally avoidable COVID-19 pandemic is one example of the extremet costs of the status quo. OneShared.World is our effort to fight for an upgrade in our world’s global operating system, based around the mutual responsibilities of interdependence. We’ve had global OS upgrades before after the Thirty Years War and after World War II, but wouldn’t it be better to make the necessary changes now to prevent a crisis of that level stemming from a nuclear war, ecosystem collapse, or deadlier synthetic biology pandemic rather than waiting until after? Revolutionary science is a global issue that must be wisely managed at every level if it is to be wisely managed at all.
How do we ensure that revolutionary technologies benefit humanity instead of undermining it?
That is the essential question. It’s why I’ve written Hacking Darwin, am writing The Great Biohack, and doing the rest of my work. If we want scietific revolutions to help, rather than hurt, us, we must all play a role building that future. This isn’t just a conversation about science, it’s about how we can draw on our most cherished values to guide the optimal development of science and technology for the common good. That must be everyone’s business.
Portions of this interview were first published in Grassia (Italy) and Zen Portugal.
Jamie Metzl is one of the world’s leading technology and healthcare futurists and author of the bestselling book, Hacking Darwin: Genetic Engineering and the Future of Humanity, which has been translated into 15 languages. In 2019, he was appointed to the World Health Organization expert advisory committee on human genome editing. Jamie is a faculty member of Singularity University and NextMed Health, a Senior Fellow of the Atlantic Council, and Founder and Chair of the global social movement, OneShared.World.
Called “the original COVID-19 whistleblower,” his pioneering role advocating for a full investigation into the origins of the COVID-19 pandemic has been featured in 60 Minutes, the New York Times, and most major media across the globe, and he was the lead witness in the first congressional hearings on this topic. Jamie previously served in the U.S. National Security Council, State Department, and Senate Foreign Relations Committee and with the United Nations in Cambodia. Jamie appears regularly on national and international media and his syndicated columns and other writing in science, technology, and global affairs are featured in publications around the world.
Jamie sits on advisory boards for multiple biotechnology and other companies and is Special Strategist to the WisdomTree BioRevolution Exchange Traded Fund. In addition to Hacking Darwin, he is author of a history of the Cambodian genocide, the historical novel The Depths of the Sea, and the genetics sci-fi thrillers Genesis Code and Eternal Sonata. His next book, The Great Biohack: Recasting Life in an age of Revolutionary Technology, will be published by Hachette in May 2024. Jamie holds a Ph.D. from Oxford, a law degree from Harvard, and an undergraduate degree from Brown and is an avid ironman triathlete and ultramarathon runner.