Could Humans Hibernate?

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istock.com/ByronOrtizA

Some animals have it made. Their whole day revolves around eating and having sex (and, to be fair, trying not to get eaten themselves). And when winter arrives, they get to curl up somewhere and wait things out until the weather is nice again. Can humans get in on this hibernation thing?

First, a note on the lingo. While people often use the term loosely to refer to any state of dormancy in animals, true hibernation is a pretty specific thing characterized by “profound reductions in metabolism, oxygen consumption and heart rate.”

A hibernating animal’s core body temperature drops to extreme lows, sometimes matching the local outside temperature. As its body cools, its metabolism slows. This reduces the need for oxygen, and its breathing will also slow, sometimes to just one to five breaths per minute. The heart rate will likewise slow to just a few beats per minute. All of this ensures that the animal’s body will conserve as much energy as possible, which is necessary because it’s largely fueling itself with a limited supply of fat. "True hibernators" don’t shut down for the whole winter, though, and occasionally rouse to use the bathroom, eat from stored food, and stretch a little so their muscles don’t atrophy. Some animals may even switch hibernation spots.

Animals go into this energy-saving mode to ride out long stretches of environmental extremes, like lack of food and water, or very cold or very hot seasonal temperatures (dormancy during cold seasons is hibernation, and dormancy in the summer is called aestivation). Humans can deal with these situations while remaining active because we have things like canned food, greenhouse tomatoes, air conditioners, heaters, and turtleneck sweaters. Our bodies aren’t required to hibernate and we’re not perfectly adapted to it, but scientists have turned up a number of ways in which we’re pretty close.

Deep Sleepers

There are plenty of documented cases of humans going into hibernation-like states. In October, 2006, rescuers found Mitsutaka Uchikoshi 24 days after he’d gone missing on western Japan’s Mount Rokko. When they discovered him, he had no detectable pulse or respiration and his body temperature had dropped to 71 degrees Fahrenheit. Doctors would later confirm that his metabolism was almost at a standstill. When he woke up, remarkably showing no signs of brain damage or other ill effects, he explained that the last thing he remembered was falling on the trail and hitting his head. The entire time he’d been missing, he was unconscious, exposed to the elements and without food or water. The doctors who treated him said that the quick onset of hypothermia slowed his body down like hibernation would, and probably saved his life.

Similar survival stories include a Norwegian skier who’d fallen into icy water and woke up unfazed after showing no heartbeat, no respiration, and a core temperature of 57ºF, and the Canadian toddler who got lost outside on a cold night and was later revived after cooling to 61ºF and exhibiting no heartbeat for a full two hours.

In a controlled experiment in the early 1970s, the Yogi Satyamurti confined himself to a small, sealed underground pit in a state of deep meditation for eight straight days while being monitored by an electrocardiogram. At first, the yogi’s heart rate was normal, and then increased to 250 bpm for a while. On the evening to the second day, the ECG flatlined and remained like that until about 30 minutes before the pit was scheduled to be opened on the last day. The astonished researchers who’d been monitoring the yogi - whose core temperature had dropped four degrees in the pit - were sure that something was wrong with their equipment, but couldn’t find any malfunction or explanation besides the yogi’s heart stopping or decreasing in electrical activity below a recordable level.

It looks like our bodies have some of the abilities needed for hibernation. But like we said already, we’ve never had to, so our bodies aren’t completely adapted to the task. A few of the things holding us back are rather big obstacles. For example, researchers at the Paul Flechsig Institute for Brain Research in Leipzig discovered a few years ago that the brains of hibernating ground squirrels have brain cells containing modified proteins that are similar to those in the brains of Alzheimer's patients. The synapses that connect the brain’s neurons in both groups were also similarly degraded. The catch is that the squirrels’ brains bounce back after hibernation. They repair themselves and the animals show no signs of damage when they wake up in the spring, while human brains in the same state continue to deteriorate.

But hibernation on-demand would be useful to humans for reasons other than avoiding winter. Inducing hibernation in an accident victim on the way to the hospital could stave off extreme blood loss and cell breakdown, plus buy surgeons extra time to repair the injuries. It would also allow for the sort of space exploration that only seems possible in the movies. Placing astronauts in a dormant state, like in the Alien franchise, would allow them to sleep off the multiple years it would take for a spacecraft to travel to the outer reaches of the solar system and beyond.

Put to Bed

Researchers have been toying around with various ways to turn hibernation states “on” in animals over the last few years. Hydrogen sulfide seems to be one possible way to do that. By binding at the same cell sites as oxygen, the gaseous compound reduces the need for oxygen and depresses the metabolism. Mark Roth at the Fred Hutchinson Cancer Research Center in Seattle induced hibernation for the first time in lab mice in 2005 by having them inhale large doses of a hydrogen sulfide gas. Their metabolic processes slowed, their temperatures dropped, and then they snapped right out of it when they got a big breath of oxygen hours later.

Surgeons at Massachusetts General Hospital took a different approach in an experiment on Yorkshire pigs, to see how beneficial induced hibernation was in a trauma setting. After anesthetizing the pigs and giving them serious wounds that led to shock and extreme blood loss, the surgeons quickly chilled the pigs' bodies to 50ºF and pumped their veins full of a solution used for preserving transplant organs. At that point, the pigs were almost dead. They had little to no heartbeat, extremely reduced blood flow and no measurable electrical activity in the brain. The surgeons operated on the pigs and repaired their injuries. The pigs were revived when their temperatures were returned to normal and warm blood was pumped back in. The pigs bounced back with no noticeable physical or cognitive impairments.

While these are incredible breakthroughs and promising starts, we’re still a long way from making human hibernation simple, safe, and reliable. Other experiments failed to induce hibernation in sheep and pigs with hydrogen sulfide, so it might not work on larger animals, including us. Testing the Massachusetts method on humans, meanwhile, would be a bit tricky, ethically speaking. It’s a start, though, and sooner or later we might move beyond mere sleep and hibernate our way through surgery, or a flight to Jupiter.

Mental Floss's Three-Day Sale Includes Deals on Apple AirPods, Sony Wireless Headphones, and More

Apple
Apple

During this weekend's three-day sale on the Mental Floss Shop, you'll find deep discounts on products like AirPods, Martha Stewart’s bestselling pressure cooker, and more. Check out the best deals below.

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Apple

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Sony

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Sony

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Martha Stewart

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Jashen

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Evachill

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Gourmia

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Townew

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FenSens

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Noerden

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Prices subject to change.

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Why Do Supreme Court Justices Serve for Life?

Chip Somodevilla/Getty Images
Chip Somodevilla/Getty Images

There are few political appointments quite as important as a nomination to the U.S. Supreme Court. Unlike a cabinet secretary or an ambassador, justices serve for life. In the modern era, that often means more than three decades on the court. Thanks to increased lifespans, justices appointed in the next century are expected to sit on the Supreme Court for an average of 35 years, compared to the average of around 16 years that judges served in the past. Because of this shift, some scholars have begun to question whether lifetime appointments are still appropriate, as the definition of “for life” has changed so much since the Constitution was written. But why do justices serve for life, anyway?

Well, for one thing, the U.S. Constitution doesn’t exactly specify that justices and the court are in a “’til death do us part” relationship. Article III says that judges (of both the Supreme Court and lower federal courts) “shall hold their offices during good behavior.” So technically, a judge could be removed if they no longer meet the “good behavior” part of the clause, but there are otherwise no limits on their term. In practice, this means they have their seat for life, unless they are impeached and removed by Congress. Only 15 federal judges in U.S. history have ever been impeached by Congress—all lower court judges—and only eight have been removed from office, though some have resigned before their inevitable removal.

The only Supreme Court justice Congress has tried to impeach was Samuel Chase, who was appointed by George Washington in 1796. Chase was an openly partisan Federalist vehemently opposed to Thomas Jefferson’s Democratic-Republican policies, and he wasn’t afraid to say so—either in his role as a lower court judge or once he was appointed to the Supreme Court. In 1804, the House of Representatives, at then-president Jefferson’s urging, voted to impeach Chase, accusing him, among other things, of promoting his political views from the bench instead of ruling as a non-partisan judge. However, he was acquitted of all counts in the Senate, and went on to serve as a Supreme Court justice until his death in 1811.

The point of giving justices a seat on the bench for the rest of their lives (or, more commonly nowadays, until they decide to retire) is to shield the nation’s highest court from the kind of partisan fighting the Chase impeachment exemplified. The Supreme Court acts as a check against the power of Congress and the president. The lifetime appointment is designed to ensure that the justices are insulated from political pressure and that the court can serve as a truly independent branch of government.

Justices can’t be fired if they make unpopular decisions, in theory allowing them to focus on the law rather than politics. Justices might be nominated because a president sees them as a political or ideological ally, but once they’re on the bench, they can’t be recalled, even if their ideology shifts. Some data, for instance, suggests that many justices actually drift leftward as they age.

The lack of term limits “is the best expedient which can be devised in any government, to secure a steady, upright, and impartial administration of the laws,” Alexander Hamilton wrote in the Federalist No. 78. The judiciary, he believed, “is in continual jeopardy of being overpowered, awed, or influenced by its coordinate branches,” and “nothing can contribute so much to its firmness and independence, as permanency in office.” Without lifetime job security, he argued, judges might feel obligated to bow to the wishes of the president, Congress, or the public, rather than confining their work strictly to questions of the Constitution.

While lifetime appointments may be a longstanding tradition in the U.S., this approach isn’t the norm in other countries. Most other democracies in the world have mandatory retirement ages if not hard-and-fast term limits for high court judges. UK Supreme Court justices face mandatory retirement at age 70 (or 75 if they were appointed before 1995), as do judges on Australia’s High Court. Canadian Supreme Court justices have a mandatory retirement age of 75, while the 31 justices of India’s Supreme Court must retire by the age of 65. Until her passing at the age of 87 on September 18, 2020, the oldest justice on the current U.S. Supreme Court was Ruth Bader Ginsburg. Oliver Wendell Holmes Jr., the oldest justice in U.S. history, retired in 1932 at age 90.

Though the U.S. Supreme Court has never had term limits before, there have recently been serious proposals to implement them. Term limits, advocates argue, could combat partisan imbalances on the court. Presidents wouldn’t get to appoint justices purely based on whether someone died while they were in office, and the stakes for political parties nominating a justice would be slightly lower, possibly leading presidents and Congress to compromise more on appointments. One popular suggestion among political analysts and scholars is to impose an 18-year term limit, though critics note that that particular plan does bring up the potential that at some point, a single president could end up appointing the majority of the justices on the court.

In any case, considering such a change would likely require a constitutional amendment, which means it’s probably not going to happen anytime soon. For the foreseeable future, being on the Supreme Court will continue to be a lifetime commitment.

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