Slowing Aging Could Transform Society As We Know It
People's lives have been getting longer for more than a century. In 1900, in even the wealthiest countries, life expectancy was under 50, according to the World Health Organization. By 2015, the worldwide average was 74, and a girl born in Japan that year could expect to live to 87. Most of that extra lifespan came from improvements in nutrition and sanitation, and the development of vaccines and antibiotics.
People's lives have been getting longer for more than a century. In 1900, in even the wealthiest countries, life expectancy was under 50, according to the World Health Organization. By 2015, the worldwide average was 74, and a girl born in Japan that year could expect to live to 87. Most of that extra lifespan came from improvements in nutrition and sanitation, and the development of vaccines and antibiotics.
The question is, how will slowing aging change society?
But now scientists are trying to move beyond just eliminating the diseases that kill us to actually slowing the aging process itself. By developing new drugs to tackle the underlying mechanisms that make our bodies grow old and frail, researchers hope to give people many more years of healthy life. The question is, how will that change society?
There are several biological mechanisms that affect aging. One involves how cells react when they're damaged. Some die, but others enter a state called senescence, in which they halt their normal growth and send out signals that something's gone wrong. That signaling causes inflammation at the sight of a wound, for instance, and triggers the body's repair processes. Once everything is back to normal, the senescent cells die off and the inflammation fades. But as we age, the machinery for clearing senescent cells becomes less efficient and they begin to pile up. Some researchers think that this accumulation of senescent cells is what causes chronic inflammation, which has been implicated in conditions such as heart disease and diabetes.
The first clinical trial in humans of senolytic drugs is happening now.
In 2015, researchers at the Mayo Clinic in Minnesota and the Scripps Research Institute in Florida tested the first so-called senolytic drugs, which cause senescent cells to die. After the scientists treated mice with a combination of an anti-cancer drug and a plant pigment that can act as an antioxidant, some of the senescent cells shrank away and caused the mouse's heart function to revert to that of a much younger mouse.
"That suggests that senescence isn't just a consequence of aging, it's actually a driver of aging," says Paul Robbins, a professor of molecular medicine at Scripps and one of the researchers involved. Other animal studies have found that reducing the number of senescent cells improves a variety of age-related conditions, such as frailty, diabetes, liver disease, pulmonary fibrosis, and osteoporosis.
Now the same researchers are moving those tests to humans in the first clinical trials of senolytic drugs. In July 2016, the Mayo Clinic launched what may be the first clinical trial of senolytic therapy, studying the effect of the two drugs, called dasatinib and quercetin, on people with chronic kidney disease, which they hope to complete in 2021. Meanwhile Mayo and Scripps researchers have identified six different biochemical pathways that give rise to senescence, along with several drug candidates that target those pathways. Robbins says it's likely that different drugs will work better for different cells in the body.
Would radical life extension lead to moral deterioration, risk aversion, and an abandonment of creativity?
In Robbins' work, treating mice with senolytic drugs has extended their median lifespan—the age at which half the animals in his experiment have died—by about 30 percent, but hasn't extended the maximum lifespan. In other words, the oldest mice treated with the drugs died at the same age as mice who hadn't been treated, but more of the mice who received senolytics lived to that ripe old age. The same may turn out to be true for humans, with more people living to the limits of the lifespan—estimated by some to be about 115—but no one living much longer. On the other hand, Robbins says, it's early days for these therapies, and it may turn out that delaying aging actually does push the limit of life farther out.
Others expect more radical extensions of human life; British gerontologist Aubrey DeGray talks about people living for 1000 years, and people who call themselves transhumanists imagine replacing body parts as they wear out, or merging our minds with computers to make us essentially immortal. Brian Green, an ethicist at Santa Clara University in California, finds that concept horrifying. He fears it would make people value their own lives too highly, demoting other moral goods such as self-sacrifice or concern for the environment. "It kind of lends itself to a moral myopia," he says. "Humans work better if they have a goal beyond their own survival." And people who live for centuries might become averse to risk, because with longer lives they have more to lose if they were to accidentally die, and might be resistant to change, draining the world of creativity.
Most researchers are focused on "extending the 'healthspan,' so that the people who live into their 90s are vigorous and disease-free."
He's not too worried, though, that that's where studies such as the Mayo Clinic's are headed, and supports that sort of research. "Hopefully these things will work, and they'll help us live a little bit longer," Green says, "but the idea of radical life extension where we're going to live indefinitely longer, I think that is very unrealistic."
Most of the researchers working on combatting aging don't, in fact, talk of unlimited lifespans. Rather, they talk about extending the "healthspan," so that the people who live into their 90s are vigorous and disease-free up until nearly the end of their lives.
If scientists can lengthen life while reducing the number of years people suffer with dementia or infirmity, that could be beneficial, says Stephen Post, a professor of medicine and director of the Center for Medical Humanities, Compassionate Care, and Bioethics at Stony Brook University in New York. But even increasing the population of vigorous 90-somethings might have negative implications for society. "What would we do with all these people who are living so long?" he asks. "Would we stop having children? Would we never retire?"
Adding 2.2 healthy years to the U.S. life by delaying aging could benefit the economy by $7.1 trillion over 50 years.
If people keep working well past their 60s, that could mean there would be fewer jobs available for younger people, says Maxwell Mehlman, professor of bioethics at Case Western Reserve University's School of Law in Ohio. Mehlman says society may have to rethink age discrimination laws, which bar firing or refusing to hire people over a certain age, to make room for younger workers. On the other hand, those who choose to retire and live another two or three decades could strain pension and entitlement systems.
But a longer healthspan could reduce costs in the healthcare system, which now are driven disproportionately by older people. Jay Olshansky, an epidemiologist at the University of Illinois at Chicago School of Public Health, has estimated that adding 2.2 healthy years to the U.S. life by delaying aging would benefit the economy by $7.1 trillion over 50 years, as spending on illnesses such as cancer and heart disease drop.
For his part, Robbins says that the scientific conferences in the anti-aging field, which tend to focus on the technical research, should hold more sessions on social and economic impacts. If anti-aging therapies start extending healthy lifespans, as he and other researchers hope they will within a decade or so, society will need to adjust.
Ultimately, it's an extension of health, not just of longevity, that will benefit us. Extra decades of senescence do nobody any good. As Green says, "Nobody wants to live in a nursing home for 1000 years."
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five, featuring interviews with Dr. David Spiegel, associate chair of psychiatry and behavioral sciences at Stanford, and Dr. Filip Swirski, professor of medicine and cardiology at the Icahn School of Medicine at Mount Sinai.
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Here are the promising studies covered in this week's Friday Five, featuring interviews with Dr. David Spiegel, associate chair of psychiatry and behavioral sciences at Stanford, and Dr. Filip Swirski, professor of medicine and cardiology at the Icahn School of Medicine at Mount Sinai.
- Breathing this way cuts down on anxiety*
- Could your fasting regimen make you sick?
- This type of job makes men more virile
- 3D printed hearts could save your life
- Yet another potential benefit of metformin
* This video with Dr. Andrew Huberman of Stanford shows exactly how to do the breathing practice.
This podcast originally aired on March 3, 2023.
Breakthrough drones deliver breast milk in rural Uruguay
Until three months ago, nurse Leopoldina Castelli used to send bottles of breast milk to nourish babies in the remote areas of Tacuarembó, in northern Uruguay, by way of ambulances or military trucks. That is, if the vehicles were available and the roads were passable, which wasn’t always the case. Now, five days per week, she stands by a runway at the hospital, located in Tacuarembó’s capital, watching a drone take off and disappear from view, carrying the milk to clinics that serve the babies’ families.
The drones can fly as far as 62 miles. Long distances and rough roads are no obstacles. The babies, whose mothers struggle to produce sufficient milk and cannot afford formula, now receive ample supplies for healthy growth. “Today we provided nourishment to a significantly larger number of children, and this is something that deeply moves me,” Castelli says.
About two decades ago, the Tacuarembó hospital established its own milk bank, supported by donations from mothers across Tacuarembó. Over the years, the bank has provided milk to infants immediately after birth. It's helped drive a “significant and sustained” decrease in infant mortality, says the hospital director, Ciro Ferreira.
But these children need breast milk throughout their first six months, if not longer, to prevent malnutrition and other illnesses that are prevalent in rural Tacuarembó. Ground transport isn't quick or reliable enough to meet this goal. It can take several hours, during which the milk may spoil due to a lack of refrigeration.
The battery-powered drones have been the difference-maker. The project to develop them, financed by the UNICEF Innovation Fund, is the first of its kind in Latin America. To Castelli, it's nothing short of a revolution. Tacuarembó Hospital, along with three rural clinics in the most impoverished part of Uruguay, are its leaders.
"This marks the first occasion when the public health system has been directly impacted [by our technology]," says Sebastián Macías, the CEO and co-founder of Cielum, an engineer at the University Republic, which collaborated on the technology with a Uruguayan company called Cielum and a Swiss company, Rigitech.
The drone can achieve a top speed of up to 68 miles per hour, is capable of flying in light rain, and can withstand winds of up to 30 miles per hour at a maximum altitude of 120 meters.
"We have succeeded in embracing the mothers from rural areas who were previously slipping through the cracks of the system," says Ferreira, the hospital director. He envisions an expansion of the service so it can improve health for children in other rural areas.
Nurses load the drone for breast milk delivery.
Sebastián Macías - Cielum
The star aircraft
The drone, which costs approximately $70,000, was specifically designed for the transportation of biological materials. Constructed from carbon fiber, it's three meters wide, two meters long and weighs 42 pounds when fully loaded. Additionally, it is equipped with a ballistic parachute to ensure a safe descent in case the technology fails in midair. Furthermore, it can achieve a top speed of 68 miles per hour, fly in light rain, and withstand winds of 30 miles per hour at a height of 120 meters.
Inside, the drones feature three refrigerated compartments that maintain a stable temperature and adhere to the United Nations’ standards for transporting perishable products. These compartments accommodate four gallons or 6.5 pounds of cargo. According to Macías, that's more than sufficient to carry a week’s worth of milk for one infant on just two flights, or 3.3 pounds of blood samples collected in a rural clinic.
“From an energy perspective, it serves as an efficient mode of transportation and helps reduce the carbon emissions associated with using an ambulance,” said Macías. Plus, the ambulance can remain available in the town.
Macías, who has led software development for the drone, and three other technicians have been trained to operate it. They ensure that the drone stays on course, monitor weather conditions and implement emergency changes when needed. The software displays the in-flight positions of the drones in relation to other aircraft. All agricultural planes in the region receive notification about the drone's flight path, departure and arrival times, and current location.
The future: doubling the drone's reach
Forty-five days after its inaugural flight, the drone is now making five flights per week. It serves two routes: 34 miles to Curtina and 31 miles to Tambores. The drone reaches Curtina in 50 minutes while ambulances take double that time, partly due to the subpar road conditions. Pueblo Ansina, located 40 miles from the state capital, will soon be introduced as the third destination.
Overall, the drone’s schedule is expected to become much busier, with plans to accomplish 20 weekly flights by the end of October and over 30 in 2024. Given the drone’s speed, Macías is contemplating using it to transport cancer medications as well.
“When it comes to using drones to save lives, for us, the sky is not the limit," says Ciro Ferreira, Tacuarembó hospital director.
In future trips to clinics in San Gregorio de Polanco and Caraguatá, the drone will be pushed to the limit. At these locations, a battery change will be necessary, but it's worth it. The route will cover up to 10 rural Tacuarembó clinics plus one hospital outside Tacuarembó, in Rivera, close to the border with Brazil. Currently, because of a shortage of ambulances, the delivery of pasteurized breast milk to Rivera only occurs every 15 days.
“The expansion to Rivera will include 100,000 more inhabitants, doubling the healthcare reach,” said Ferreira, the director of the Tacuarembó Hospital. In itself, Ferreira's hospital serves the medical needs of 500,000 people as one of the largest in Uruguay's interior.
Alejandro Del Estal, an aeronautical engineer at Rigitech, traveled from Europe to Tacuarembó to oversee the construction of the vertiports – the defined areas that can support drones’ take-off and landing – and the first flights. He pointed out that once the flight network between hospitals and rural polyclinics is complete in Uruguay, it will rank among the five most extensive drone routes in the world for any activity, including healthcare and commercial uses.
Cielum is already working on the long-term sustainability of the project. The aim is to have more drones operating in other rural regions in the western and northern parts of the country. The company has received inquiries from Argentina and Colombia, but, as Macías pointed out, they are exercising caution when making commitments. Expansion will depend on the development of each country’s regulations for airspace use.
For Ferreira, the advantages in Uruguay are evident: "This approach enables us to bridge the geographical gap, enhance healthcare accessibility, and reduce the time required for diagnosing and treating rural inhabitants, all without the necessity of them traveling to the hospital,” he says. "When it comes to using drones to save lives, for us, the sky is not the limit."