“Coming Back from the Dead” Is No Longer Science Fiction
Last year, there were widespread reports of a 53-year-old Frenchman who had suffered a cardiac arrest and "died," but was then resuscitated back to life 18 hours after his heart had stopped.
The once black-and-white line between life and death is now blurrier than ever.
This was thought to have been possible in part because his body had progressively cooled down naturally after his heart had stopped, through exposure to the outside cold. The medical team who revived him were reported as being "stupefied" that they had been able to bring him back to life, in particular since he had not even suffered brain damage.
Interestingly, this man represents one of a growing number of extraordinary cases in which people who would otherwise be declared dead have now been revived. It is a testament to the incredible impact of resuscitation science -- a science that is providing opportunities to literally reverse death, and in doing so, shedding light on the age-old question of what happens when we die.
Death: Past and Present
Throughout history, the boundary between life and death was marked by the moment a person's heart stopped, breathing ceased, and brain function shut down. A person became motionless, lifeless, and was deemed irreversibly dead. This is because once the heart stops beating, blood flow stops and oxygen is cut off from all the body's organs, including the brain. Consequently, within seconds, breathing stops and brain activity comes to a halt. Since the cessation of the heart literally occurs in a "moment," the philosophical notion of a specific point in time of "irreversible" death still pervades society today. The law, for example, relies on "time of death," which corresponds to when the heart stops beating.
The advent of cardiopulmonary resuscitation (CPR) in the 1960s was revolutionary, demonstrating that the heart could potentially be restarted after it had stopped, and what had been a clear black-and-white line was shown to be potentially reversible in some people. What was once called death—the ultimate end point— was now widely called cardiac arrest, and became a starting point.
From then on, it was only if somebody had requested not to be resuscitated or when CPR was deemed to have failed that people would be declared dead by "cardiopulmonary criteria." Biologically, cardiac arrest and death by cardiopulmonary criteria are the same process, albeit marked at different points in time depending on when a declaration of death is made.
The apparent irreversibility of death as we know it may not necessarily reflect true irretrievable cellular damage inside the body.
Clearly, contrary to many people's perceptions, cardiac arrest is not a heart attack; it is the final step in death irrespective of cause, whether it be a stroke, a heart attack, a car accident, an overwhelming infection or cancer. This is how roughly 95 percent of the population are declared dead.
The only exception is the small proportion of people who may have suffered catastrophic brain injuries, but whose hearts can be artificially kept beating for a period of time on life-support machines. These people can be legally declared dead based on brain death criteria before their hearts have stopped. This is because the brain can die either from oxygen starvation after cardiac arrest or from massive trauma and internal bleeding. Either way, the brain dies hours or possibly longer after these injuries have taken place and not just minutes.
A Profound Realization
What has become increasingly clear is that the apparent irreversibility of death as we know it may not necessarily reflect true irretrievable cellular damage inside the body. This is consistent with a mounting understanding: it is only after a person actually dies that the cells in the body start to undergo their own process of death. Intriguingly, this process is something that can now be manipulated through medical intervention. Being cold is one of the factors that slows down the rate of cellular decay. The 53-year-old Frenchman's case and the other recent cases of resuscitation after prolonged periods of time illustrate this new understanding.
Last week's earth-shattering announcement by neuroscientist Dr. Nenad Sestan and his team out of Yale, published in the prestigious scientific journal Nature, provides further evidence that a time gap exists between actual death and cellular death in cadavers. In this seminal study, these researchers were able to restore partial function in pig brains four hours after their heads were severed from their bodies. These results follow from the pioneering work in 2001 of geneticist Fred Gage and colleagues from the Salk Institute, also published in Nature, which demonstrated the possibility of growing human brain cells in the laboratory by taking brain biopsies from cadavers in the mortuary up to 21 hours post-mortem.
The once black-and-white line between life and death is now blurrier than ever. Some people may argue this means these humans and pigs weren't truly "dead." However, that is like saying the people who were guillotined during the French Revolution were also not dead. Clearly, that is not the case. They were all dead. The problem is not death; it's our reliance on an outdated philosophical, rather than biological, notion of death.
Death can no longer be considered an absolute moment but rather a process that can be reversed even many hours after it has taken place.
But the distinction between irreversibility from a medical perspective and biological irreversibility may not matter much from a pragmatic perspective today. If medical interventions do not exist at any given time or place, then of course death cannot be reversed.
However, it is crucial to distinguish between biologically and medically: When "irreversible" loss of function arises due to inadequate treatment, then a person could be potentially brought back in the future when an alternative therapy becomes available, or even today if he or she dies in a location where novel treatments can slow down the rate of cell death. However, when true irreversible loss of function arises from a biological perspective, then no treatment will ever be able to reverse the process, whether today, tomorrow, or in a hundred years.
Probing the "Grey Zone"
Today, thanks to modern resuscitation science, death can no longer be considered an absolute moment but rather a process that can be reversed even many hours after it has taken place. How many hours? We don't really know.
One of the wider implications of our medical advances is that we can now study what happens to the human mind and consciousness after people enter the "grey zone," which marks the time after the heart stops, but before irreversible and irretrievable cell damage occurs, and people are then brought back to life. Millions have been successfully revived and many have reported experiencing a unique, universal, and transformative mental state.
Were they "dead"? Yes, according to all the criteria we have ever used. But they were able to be brought back before their "dead" bodies had reached the point of permanent, irreversible cellular damage. This reflects the period of death for all of us. So rather than a "near-death experience," I prefer a new terminology to describe these cases -- "an actual-death experience." These survivors' unique experiences are providing eyewitness testimonies of what we will all be likely to experience when we die.
Such an experience reportedly includes seeing a warm light, the presence of a compassionate perfect individual, deceased relatives, a review of their lives, a judgment of their actions and intentions as they pertain to their humanity, and in some cases a sensation of seeing doctors and nurses working to resuscitate them.
Are these experiences compatible with hallucinations or illusions? No -- in part, because these people have described real, verifiable events, which, by definition are not hallucinations, and in part, because their experiences are not compatible with confused and delirious memories that characterize oxygen deprivation.
The challenge for us scientifically is understanding how this is possible at a time when all our science tells us the brain shuts down.
For instance, it is hard to classify a structured meaningful review of one's life and one's humanity as hallucinatory or illusory. Instead, these experiences represent a new understanding of the overall human experience of death. As an intensive care unit physician for more than 10 years, I have seen numerous cases where these reports have been corroborated by my colleagues. In short, these survivors have been known to come back with reports of full consciousness, with lucid, well-structured thought processes and memory formation.
The challenge for us scientifically is understanding how this is possible at a time when all our science tells us the brain shuts down. The fact that these experiences occur is a paradox and suggests the undiscovered entity we call the "self," "consciousness," or "psyche" – the thing that makes us who we are - may not become annihilated at the point of so-called death.
At New York University, the State University of New York, and across 20 hospitals in the U.S. and Europe, we have brought together a new multi-disciplinary team of experts across many specialties, including neurology, cardiology, and intensive care. Together, we hope to improve cardiac arrest prevention and treatment, as well as to address the impact of new scientific discoveries on our understanding of what happens at death.
One of our first studies, Awareness during Resuscitation (AWARE), published in the medical journal Resuscitation in 2014, confirmed that some cardiac arrest patients report a perception of awareness without recall; others report detailed memories and experiences; and a few report full auditory and visual awareness and consciousness of their experience, from a time when brain function would be expected to have ceased.
While you probably have some opinion or belief about this based upon your own philosophical, religious, or cultural background, you may not realize that exploring what happens when we die is now a subject that science is beginning to investigate.
There is no question more intriguing to humankind. And for the first time in our history, we may finally uncover some real answers.
Technology is Redefining the Age of 'Older Mothers'
In October 2021, a woman from Gujarat, India, stunned the world when it was revealed she had her first child through in vitro fertilization (IVF) at age 70. She had actually been preceded by a compatriot of hers who, two years before, gave birth to twins at the age of 73, again with the help of IVF treatment. The oldest known mother to conceive naturally lived in the UK; in 1997, Dawn Brooke conceived a son at age 59.
These women may seem extreme outliers, almost freaks of nature; in the US, for example, the average age of first-time mothers is 26. A few decades from now, though, the sight of 70-year-old first-time mothers may not even raise eyebrows, say futurists.
“We could absolutely have more 70-year-old mothers because we are learning how to regulate the aging process better,” says Andrew Hessel, a microbiologist and geneticist, who cowrote "The Genesis Machine," a book about “rewriting life in the age of synthetic biology,” with Amy Webb, the futurist who recently wondered why 70-year-old women shouldn’t give birth.
Technically, we're already doing this, says Hessel, pointing to a technique known as in vitro gametogenesis (IVG). IVG refers to turning adult cells into sperm or egg cells. “You can think of it as the upgrade to IVF,” Hessel says. These vanguard stem cell research technologies can take even skin cells and turn them into induced pluripotent stem cells (iPSCs), which are basically master cells capable of maturing into any human cell, be it kidney cells, liver cells, brain cells or gametes, aka eggs and sperm, says Henry T. “Hank” Greely, a Stanford law professor who specializes in ethical, legal, and social issues in biosciences.
Mothers over 70 will be a minor blip, statistically speaking, Greely predicts.
In 2016, Greely wrote "The End of Sex," a book in which he described the science of making gametes out of iPSCs in detail. Greely says science will indeed enable us to see 70-year-old new mums fraternize with mothers several decades younger at kindergartens in the (not far) future. And it won’t be that big of a deal.
“An awful lot of children all around the world have been raised by grandmothers for millennia. To have 70-year-olds and 30-year-olds mingling in maternal roles is not new,” he says. That said, he doubts that many women will want to have a baby in the eighth decade of their life, even if science allows it. “Having a baby and raising a child is hard work. Even if 1% of all mothers are over 65, they aren’t going to change the world,” Greely says. Mothers over 70 will be a minor blip, statistically speaking, he predicts. But one thing is certain: the technology is here.
And more technologies for the same purpose could be on the way. In March 2021, researchers from Monash University in Melbourne, Australia, published research in Nature, where they successfully reprogrammed skin cells into a three-dimensional cellular structure that was morphologically and molecularly similar to a human embryo–the iBlastoid. In compliance with Australian law and international guidelines referencing the “primitive streak rule," which bans the use of embryos older than 14 days in scientific research, Monash scientists stopped growing their iBlastoids in vitro on day 11.
“The research was both cutting-edge and controversial, because it essentially created a new human life, not for the purpose of a patient who's wanting to conceive, but for basic research,” says Lindsay Wu, a senior lecturer in the School of Medical Sciences at the University of New South Wales (UNSW), in Kensington, Australia. If you really want to make sure what you are breeding is an embryo, you need to let it develop into a viable baby. “This is the real proof in the pudding,'' says Wu, who runs UNSW’s Laboratory for Ageing Research. Then you get to a stage where you decide for ethical purposes you have to abort it. “Fiddling here a bit too much?” he asks. Wu believes there are other approaches to tackling declining fertility due to older age that are less morally troubling.
He is actually working on them. Why would it be that women, who are at peak physical health in almost every other regard, in their mid- to late- thirties, have problems conceiving, asked Wu and his team in a research paper published in 2020 in Cell Reports. The simple answer is the egg cell. An average girl in puberty has between 300,000 and 400,000 eggs, while at around age 37, the same woman has only 25,000 eggs left. Things only go downhill from there. So, what torments the egg cells?
The UNSW team found that the levels of key molecules called NAD+ precursors, which are essential to the metabolism and genome stability of egg cells, decline with age. The team proceeded to add these vitamin-like substances back into the drinking water of reproductively aged, infertile lab mice, which then had babies.
“It's an important proof of concept,” says Wu. He is investigating how safe it is to replicate the experiment with humans in two ongoing studies. The ultimate goal is to restore the quality of egg cells that are left in patients in their late 30s and early- to mid-40s, says Wu. He sees the goal of getting pregnant for this age group as less ethically troubling, compared to 70-year-olds.
But what is ethical, anyway? “It is a tricky word,” says Hessel. He differentiates between ethics, which represent a personal position and may, thus, be more transient, and morality, longer lasting principles embraced across society such as, “Thou shalt not kill.” Unprecedented advances often bring out fear and antagonism until time passes and they just become…ordinary. When IVF pioneer Landrum Shettles tried to perform IVF in 1973, the chairman of Columbia’s College of Physicians and Surgeons interdicted the procedure at the last moment. Almost all countries in the world have IVF clinics today, and the global IVF services market is clearly a growth industry.
Besides, you don’t have a baby at 70 by accident: you really want it, Greely and Hessel agree. And by that age, mothers may be wiser and more financially secure, Hessel says (though he is quick to add that even the pregnancy of his own wife, who had her child at 40, was a high-risk one).
As a research question, figuring out whether older mothers are better than younger ones and vice-versa entails too many confounding variables, says Greely. And why should we focus on who’s the better mother anyway? “We've had 70-year-old and 80-year-old fathers forever–why should people have that much trouble getting used to mothers doing the same?” Greely wonders. For some women having a child at an old(er) age would be comforting; maybe that’s what matters.
And the technology to enable older women to have children is already here or coming very soon. That, perhaps, matters even more. Researchers have already created mice–and their offspring–entirely from scratch in the lab. “Doing this to produce human eggs is similar," says Hessel. "It is harder to collect tissues, and the inducing cocktails are different, but steady advances are being made." He predicts that the demand for fertility treatments will keep financing research and development in the area. He says that big leaps will be made if ethical concerns don’t block them: it is not far-fetched to believe that the first baby produced from lab-grown eggs will be born within the next decade.
In an op-ed in 2020 with Stat, Greely argued that we’ve already overcome the technical barrier for human cloning, but no one's really talking about it. Likewise, scientists are also working on enabling 70-year-old women to have babies, says Hessel, but most commentators are keeping really quiet about it. At least so far.
New Cell Therapies Give Hope to Diabetes Patients
For nearly four decades, George Huntley has thought constantly about his diabetes. Diagnosed in 1983 with Type 1 (insulin-dependent) diabetes, Huntley began managing his condition with daily finger sticks to check his blood glucose levels and doses of insulin that he injected into his abdomen. Even now, with an insulin pump and a device that continuously monitors his glucose, he must consider how every meal will affect his blood sugar, checking his monitor multiple times each hour.
Like many of those who depend on insulin injections, Huntley is simultaneously grateful for the technology that makes his condition easier to manage and tired of thinking about diabetes. If he could wave a magic wand, he says, he would make his diabetes disappear. So when he read about biotechs like ViaCyte and Vertex Pharmaceuticals developing new cell therapies that have the potential to cure Type 1 diabetes, Huntley was excited.
You also won’t see him signing up any time soon. The therapies under development by both companies would require a lifelong regimen of drugs for suppressing the immune system to prevent the body from rejecting the foreign cells. It’s a problem also seen in the transplant of insulin-producing cells of the pancreas – called islet cells – from deceased donors. To Howard Foyt, chief medical officer at ViaCyte, a San Diego-based biotech specializing in the development of cell therapies for diabetes, the tradeoff is worth it.
“A lot of the symptoms of diabetes are not something that you wear on your arm, so to speak. You’re not necessarily conscious of them until you’re successfully treated, and you feel better,” Foyt says.
For many with diabetes, managing these symptoms is a constant game of Whack-a-Mole. “Any form of treatment that gets someone closer to feeling good is a victory,” he says.
“Am I going to be trading diabetes for cancer? That’s not a chance I
want to take."
But not everyone is convinced. What’s more, it’s likely that the availability of these cell therapies will be limited to those with life-threatening diabetes symptoms, such as hypoglycemia unawareness. To Huntley, these therapies remain a bit of a Faustian bargain.
“Am I going to be trading diabetes for cancer? That’s not a chance I want to take,” he says.
The discovery of insulin in 1921 transformed Type 1 diabetes from a death sentence into a potentially manageable condition. Even as better versions of insulin hit the market—ones that weren’t derived from pigs and wouldn’t provoke an allergic response, longer-acting insulin, insulin pens—they didn’t change the reality that those with Type 1 diabetes remained dependent on insulin. Even the most advanced continuous glucose monitors (which tests blood sugar levels every few minutes, 24/7) and insulin pumps don’t perform as well as a healthy pancreas.
Whether by injection or pump, someone with diabetes needs to administer the insulin their body no longer makes. With advances in organ transplantation, the concept of transplanting insulin-producing pancreatic beta cells seemed obvious. After more than a decade of painstaking work, James Shapiro, who directs the Islet Transplant Program at the University of Albania, honed a process called the Edmonton Protocol for pancreas transplants. For a few patients who couldn’t control their blood sugars any other way, the Edmonton Protocol became a life saver. Some of these patients were even able to stop insulin completely, Shapiro says. But the high cost of organ transplant and a chronic shortage of donor organs, pancreas or otherwise, meant that only a small handful of patients could benefit.
Stem cells, however, can be grown in vats, meaning that supply would never be an issue. “We would be going from a very successful treatment of today to a potential cure tomorrow,” Shapiro says.
In 2014, spurred by his own children’s diagnoses with Type 1 Diabetes, stem cell biologist Doug Melton of Harvard University figured out a way to differentiate embryonic stem cells into functional pancreatic beta cells. It was a long process, explains immunoengineer Alice Tomei at the University of Miami, because “the islet is not one cell, it's like a mini-organ that has its own needs.”
Add on the risk of rejection and autoimmunity, and Tomei says that scientists soon realized that chronic and systemic immunosuppression was the only way forward. Over the next several years, Melton improved his approach to yield more cells with fewer impurities. Melton partnered with Boston-based Vertex Pharmaceuticals to create a cell therapy called VX-880.
The first patient received his dose earlier in 2021. In October, Vertex released 90-day results from the Phase 1/2 trial, which revealed the patient was able to reduce his insulin usage from an average of 34 units per day to just 2.9 units per day. The tradeoff is a lifelong need for immunosuppressive drugs to prevent the body from attacking both foreign cells and pancreatic beta cells. It’s what recipients of ViaCyte’s first-gen PEC-Direct will also need. For Foyt, it’s an easy choice.
“At this point in time, immunosuppression is the necessary evil,” he says. “For parents, would you like to worry about going into your child’s bedroom every morning and not knowing if they’re going to be alive or dead? It’s uncommon, but it does occur.”
Not everyone, however, finds the trade-off easy to swallow. Especially with COVID-19 cases reaching record highs, the prospect of reducing his immune function at a time when he needs it most doesn’t sit well with Huntley. The risks of immunosuppression also mean that diabetes cell therapies are limited to those patients with life-threatening complications.
It’s why ViaCyte has created two new iterations of cellular therapies that would eliminate this need. The ViaCyte-Encap contains the cells in a permeable container that allows oxygen, insulin, and nutrients to flow freely but prevents immune system access. Their latest model, PEC-QT, just began safety trials with Shapiro’s lab at the University of Alberta and uses gene editing to eliminate any cellular markers that would trigger an immune response.
Sanjoy Dutta, vice president of research at JDRF International, a nonprofit that funds the study of diabetes, is thrilled with the progress that’s been made around cell therapies, but he cautions it’s still early days. “We have proven that these cells can be made. What we haven’t seen is are they going to work for six months, two years, five years? It’s a challenge we still need to overcome,” he says.
Iowa social worker Jodi Lynn’s concerns echo Dutta’s. Lynn was diagnosed with diabetes in 1998 at age 14 after a bout of severe influenza, spends each day inventorying supplies, planning her food intake, and maintaining her insulin pump and glucose monitor. These newer technologies dramatically improved her blood sugar control but, like everyone with diabetes, Lynn remains at high risk for complications, such as diabetic ketoacidosis, heart disease, vision loss, and kidney failure. Lynn, already considered immunocompromised due to medications she takes for another autoimmune condition, is less concerned with immune suppression than the untested nature of these therapies.
“I want to know that they will work long-term,” she says.