Drugs That Could Slow Aging May Hold Promise for Protecting the Elderly from COVID-19
Although recent data has shown the coronavirus poses a greater risk to young people than previously understood, the ensuing COVID-19 disease is clearly far more dangerous for older people than it is for the young.
If we want to lower the COVID-19 fatality rate, we must also make fortifying our most vulnerable hosts a central part of our approach.
While our older adults have accrued tremendous knowledge, wisdom, and perspective over the years, their bodies have over time become less able to fight off viruses and other insults. The shorthand name for this increased susceptibility is aging.
We may have different names for the diseases which disproportionately kill us -- cancer, heart disease, and dementia among them – but what is really killing us is age. The older we are, the greater the chance we'll die from one or another of these afflictions. Eliminate any one completely - including cancer - and we won't on average live that much longer. But if we slow aging on a cellular level, we can counter all of these diseases at once, including COVID-19.
Every army needs both offensive and defensive capabilities. In our war against COVID-19, our offense strategy is to fight the virus directly. But strengthening our defense requires making us all more resistant to its danger. That's why everyone needs to be eating well, exercising, and remaining socially connected. But if we want to lower the COVID-19 fatality rate, we must also make fortifying our most vulnerable hosts a central part of our approach. That's where our new fight against this disease and the emerging science of aging intersect.
Once the domain of charlatans and delusionists, the millennia-old fantasy of extending our healthy lifespans has over the past century become real. But while the big jump in longevity around the world over the past hundred years or so is mostly attributable to advances in sanitation, nutrition, basic healthcare, and worker safety, advances over the next hundred will come from our increasing ability to hack the biology of aging itself.
A few decades ago, scientists began recognizing that some laboratory animals on calorie-restricted diets tended to live healthier, longer lives. Through careful experiments derived from these types of insights, scientists began identifying specific genetic, epigenetic, and metabolic pathways that influence how we age. A range of studies have recently suggested that systemic knobs might metaphorically be turned to slow the cellular aging process, making us better able to fight off diseases and viral attacks.
Among the most promising of these systemic interventions is a drug called metformin, which targets many of the hallmarks of aging and extends health span and lifespan in animals. Metformin has been around since the Middle Ages and has been used in Europe for over 60 years to treat diabetes. This five-cent pill became the most prescribed drug in the world after being approved by the FDA in 1994.
With so many people taking it, ever larger studies began suggesting metformin's positive potential effects preventing diabetes, cardiovascular diseases, cancer, and dementia. In fact, elderly people on metformin for their diabetes have around a 20 percent lower mortality than age-matched subjects without diabetes. Results like these led scientists to hypothesize that metformin wasn't just impacting a few individual diseases but instead having a systemic impact on entire organisms.
Another class of drug that seems to slow the systemic process of aging in animal models and very preliminary human trials inhibits a nutrient-sensing cellular protein called mTOR. A new category of drugs called rapalogues has been shown to extend healthspan and lifespan in every type of non-human animal so far tested. Two recent human studies indicated that rapalogues increased resistance to the flu and decreased the severity of respiratory tract infections in older adults.
If COVID-19 is primarily a severe disease of aging, then countering aging should logically go a long way in countering the disease.
These promising early indications have inspired a recently launched long-term study exploring how metformin and rapalogues might delay the onset of multiple, age-related diseases and slow the biological process of aging in humans. Under normal circumstances, studies like this seeking to crack the biological code of aging would continue to proceed slowly and carefully over years, moving from animal experiments to cautious series of human trials. But with deaths rising by the day, particularly of older people, these are not times for half measures. Wartimes have always demanded new ways of doing important things at warp speeds.
If COVID-19 is primarily a severe disease of aging, then countering aging should logically go a long way in countering the disease. We need to find out. Fast.
Although it would be a mistake for older people to just begin taking drugs like these without any indication, pushing to massively speed up our process for assessing whether these types of interventions can help protect older people is suddenly critical.
To do this, we need U.S. government agencies like the Department of Health and Human Services' Biomedical Advanced Research and Development Authority (BARDA) to step up. BARDA currently only funds COVID-19 clinical trials of drugs that can be dosed once and provide 60 days of protection. Metformin and rapalogues are not considered for BARDA funding because they are dosed once daily. This makes no sense because a drug that provides 60 days of protection from the coronavirus after a single dose does not yet exist, while metformin and rapalogues have already passed extensive safety tests. Instead, BARDA should consider speeding up trials with currently available drugs that could help at least some of the elderly populations at risk.
Although the U.S. Food and Drug Administration and Centers for Disease Control are ramping up their approval processes and even then needs to prioritize efforts, they too must find a better balance between appropriate regulatory caution and the dire necessities of our current moment. Drugs like metformin and rapalogues that have shown preliminary efficacy ought to be fast-tracked for careful consideration.
One day we will develop a COVID-19 vaccine to help everyone. But that could be at least a year from now, if not more. Until we get there and even after we do, speeding up our process of fortifying our older populations mush be a central component of our wartime strategy.
And when the war is won and life goes back to a more normal state, we'll get the added side benefit of a few more months and ultimately years with our parents and grandparents.
As Our AI Systems Get Better, So Must We
As the power and capability of our AI systems increase by the day, the essential question we now face is what constitutes peak human. If we stay where we are while the AI systems we are unleashing continually get better, they will meet and then exceed our capabilities in an ever-growing number of domains. But while some technology visionaries like Elon Musk call for us to slow down the development of AI systems to buy time, this approach alone will simply not work in our hyper-competitive world, particularly when the potential benefits of AI are so great and our frameworks for global governance are so weak. In order to build the future we want, we must also become ever better humans.
The list of activities we once saw as uniquely human where AIs have now surpassed us is long and growing. First, AI systems could beat our best chess players, then our best Go players, then our best champions of multi-player poker. They can see patterns far better than we can, generate medical and other hypotheses most human specialists miss, predict and map out new cellular structures, and even generate beautiful, and, yes, creative, art.
A recent paper by Microsoft researchers analyzing the significant leap in capabilities in OpenAI’s latest AI bot, ChatGPT-4, asserted that the algorithm can “solve novel and difficult tasks that span mathematics, coding, vision, medicine, law, psychology and more, without needing any special prompting.” Calling this functionality “strikingly close to human-level performance,” the authors conclude it “could reasonably be viewed as an early (yet still incomplete) version of an artificial general intelligence (AGI) system.”
The concept of AGI has been around for decades. In its common use, the term suggests a time when individual machines can do many different things at a human level, not just one thing like playing Go or analyzing radiological images. Debating when AGI might arrive, a favorite pastime of computer scientists for years, now has become outdated.
We already have AI algorithms and chatbots that can do lots of different things. Based on the generalist definition, in other words, AGI is essentially already here.
Unfettered by the evolved capacity and storage constraints of our brains, AI algorithms can access nearly all of the digitized cultural inheritance of humanity since the dawn of recorded history and have increasing access to growing pools of digitized biological data from across the spectrum of life.
Once we recognize that both AI systems and humans have unique superpowers, the essential question becomes what each of us can do better than the other and what humans and AIs can best do in active collaboration. The future of our species will depend upon our ability to safely, dynamically, and continually figure that out.
With these ever-larger datasets, rapidly increasing computing and memory power, and new and better algorithms, our AI systems will keep getting better faster than most of us can today imagine. These capabilities have the potential to help us radically improve our healthcare, agriculture, and manufacturing, make our economies more productive and our development more sustainable, and do many important things better.
Soon, they will learn how to write their own code. Like human children, in other words, AI systems will grow up. But even that doesn’t mean our human goose is cooked.
Just like dolphins and dogs, these alternate forms of intelligence will be uniquely theirs, not a lesser or greater version of ours. There are lots of things AI systems can't do and will never be able to do because our AI algorithms, for better and for worse, will never be human. Our embodied human intelligence is its own thing.
Our human intelligence is uniquely ours based on the capacities we have developed in our 3.8-billion-year journey from single cell organisms to us. Our brains and bodies represent continuous adaptations on earlier models, which is why our skeletal systems look like those of lizards and our brains like most other mammals with some extra cerebral cortex mixed in. Human intelligence isn’t just some type of disembodied function but the inextricable manifestation of our evolved physical reality. It includes our sensory analytical skills and all of our animal instincts, intuitions, drives, and perceptions. Disembodied machine intelligence is something different than what we have evolved and possess.
Because of this, some linguists including Noam Chomsky have recently argued that AI systems will never be intelligent as long as they are just manipulating symbols and mathematical tokens without any inherent understanding. Nothing could be further from the truth. Anyone interacting with even first-generation AI chatbots quickly realizes that while these systems are far from perfect or omniscient and can sometimes be stupendously oblivious, they are surprisingly smart and versatile and will get more so… forever. We have little idea even how our own minds work, so judging AI systems based on their output is relatively close to how we evaluate ourselves.
Anyone not awed by the potential of these AI systems is missing the point. AI’s newfound capacities demand that we work urgently to establish norms, standards, and regulations at all levels from local to global to manage the very real risks. Pausing our development of AI systems now doesn’t make sense, however, even if it were possible, because we have no sufficient ways of uniformly enacting such a pause, no plan for how we would use the time, and no common framework for addressing global collective challenges like this.
But if all we feel is a passive awe for these new capabilities, we will also be missing the point.
Human evolution, biology, and cultural history are not just some kind of accidental legacy, disability, or parlor trick, but our inherent superpower. Our ancestors outcompeted rivals for billions of years to make us so well suited to the world we inhabit and helped build. Our social organization at scale has made it possible for us to forge civilizations of immense complexity, engineer biology and novel intelligence, and extend our reach to the stars. Our messy, embodied, intuitive, social human intelligence is roughly mimicable by AI systems but, by definition, never fully replicable by them.
Once we recognize that both AI systems and humans have unique superpowers, the essential question becomes what each of us can do better than the other and what humans and AIs can best do in active collaboration. We still don't know. The future of our species will depend upon our ability to safely, dynamically, and continually figure that out.
As we do, we'll learn that many of our ideas and actions are made up of parts, some of which will prove essentially human and some of which can be better achieved by AI systems. Those in every walk of work and life who most successfully identify the optimal contributions of humans, AIs, and the two together, and who build systems and workflows empowering humans to do human things, machines to do machine things, and humans and machines to work together in ways maximizing the respective strengths of each, will be the champions of the 21st century across all fields.
The dawn of the age of machine intelligence is upon us. It’s a quantum leap equivalent to the domestication of plants and animals, industrialization, electrification, and computing. Each of these revolutions forced us to rethink what it means to be human, how we live, and how we organize ourselves. The AI revolution will happen more suddenly than these earlier transformations but will follow the same general trajectory. Now is the time to aggressively prepare for what is fast heading our way, including by active public engagement, governance, and regulation.
AI systems will not replace us, but, like these earlier technology-driven revolutions, they will force us to become different humans as we co-evolve with our technology. We will never reach peak human in our ongoing evolutionary journey, but we’ve got to manage this transition wisely to build the type of future we’d like to inhabit.
Alongside our ascending AIs, we humans still have a lot of climbing to do.
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Our gut microbiome plays a substantial role in our health and well-being. Most research, however, focuses on bacteria, rather than the viruses that hide within them. Now, research from the University of Copenhagen, newly published in Nature Microbiology, found that people who live past age 100 have a greater diversity of bacteria-infecting viruses in their intestines than younger people. Furthermore, they found that the viruses are linked to changes in bacterial metabolism that may support mucosal integrity and resistance to pathogens.
The microbiota and aging
In the early 1970s, scientists discovered that the composition of our gut microbiota changes as we age. Recent studies have found that the changes are remarkably predictable and follow a pattern: The microbiota undergoes rapid, dramatic changes as toddlers transition to solid foods; further changes become less dramatic during childhood as the microbiota strikes a balance between the host and the environment; and as that balance is achieved, the microbiota remains mostly stable during our adult years (ages 18-60). However, that stability is lost as we enter our elderly years, and the microbiome undergoes dramatic reorganization. This discovery led scientists to question what causes this change and what effect it has on health.
Centenarians have a distinct gut community enriched in microorganisms that synthesize potent antimicrobial molecules that can kill multidrug-resistant pathogens.
“We are always eager to find out why some people live extremely long lives. Previous research has shown that the intestinal bacteria of old Japanese citizens produce brand-new molecules that make them resistant to pathogenic — that is, disease-promoting — microorganisms. And if their intestines are better protected against infection, well, then that is probably one of the things that cause them to live longer than others,” said Joachim Johansen, a researcher at the University of Copenhagen.
In 2021, a team of Japanese scientists set out to characterize the effect of this change on older people’s health. They specifically wanted to determine if people who lived to be over 100 years old — that is, centenarians — underwent changes that provided them with unique benefits. They discovered centenarians have a distinct gut community enriched in microorganisms that synthesize potent antimicrobial molecules that can kill multidrug-resistant pathogens, including Clostridioides difficile and Enterococcus faecium. In other words, the late-life shift in microbiota reduces an older person’s susceptibility to common gut pathogens.
Viruses can change alter the genes of bacteria
Although the late-in-life microbiota change could be beneficial to health, it remained unclear what facilitated this shift. To solve this mystery, Johansen and his colleagues turned their attention to an often overlooked member of the microbiome: viruses. “Our intestines contain billions of viruses living inside bacteria, and they could not care less about human cells; instead, they infect the bacterial cells. And seeing as there are hundreds of different types of bacteria in our intestines, there are also lots of bacterial viruses,” said Simon Rasmussen, Johansen’s research advisor.
Centenarians had a more diverse virome, including previously undescribed viral genera.
For decades, scientists have explored the possibility of phage therapy — that is, using viruses that infect bacteria (called bacteriophages or simply phages) to kill pathogens. However, bacteriophages can also enhance the bacteria they infect. For example, they can provide genes that help their bacterial host attack other bacteria or provide new metabolic capabilities. Both of these can change which bacteria colonize the gut and, in turn, protect against certain disease states.
Intestinal viruses give bacteria new abilities
Johansen and his colleagues were interested in what types of viruses centenarians had in their gut and whether those viruses carried genes that altered metabolism. They compared fecal samples of healthy centenarians (100+ year-olds) with samples from younger patients (18-100 year-olds). They found that the centenarians had a more diverse virome, including previously undescribed viral genera.
They also revealed an enrichment of genes supporting key steps in the sulfate metabolic pathway. The authors speculate that this translates to increased levels of microbially derived sulfide, which may lead to health-promoting outcomes, such as supporting mucosal integrity and resistance to potential pathogens.
“We have learned that if a virus pays a bacterium a visit, it may actually strengthen the bacterium. The viruses we found in the healthy Japanese centenarians contained extra genes that could boost the bacteria,” said Johansen.
Simon Rasmussen added, “If you discover bacteria and viruses that have a positive effect on the human intestinal flora, the obvious next step is to find out whether only some or all of us have them. If we are able to get these bacteria and their viruses to move in with the people who do not have them, more people could benefit from them.”
This article originally appeared on Big Think, home of the brightest minds and biggest ideas of all time.
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