Cryopreservation and human hibernation: what is it, does it really work?


The desire to extend life while waiting for a cure is the idea behind human cryopreservation or hibernation.

Those who wish and can afford it can freeze their bodies after death, waiting for science to make such progress that they can revive the deceased and replace their sick cells with healthy ones.

The technique is expensive and controversial. To date, no one is able to predict whether it will be possible to bring hibernated bodies back to life because there is still no technology to do so.

The first man to be hibernated was James Bedford who died of cancer on 12 January 1967 at the age of 73.
In 1991 his body was transferred into a more modern container and with the occasion it was possible to see its perfect state of preservation.
In fact, the possibility to freeze his body was already offered in 1965 by Evan Cooper, an entrepreneur who had founded Life Extension, which later became Alcor.
The first candidates died suddenly, however, and it was impossible to cryopreserve the bodies in time.

James Bedford
James Bedford

Although there is no scientific certainty about cryonics, to date more than 300 people in the world have decided to entrust their bodies or heads to hibernation.

What is cryopreservation

Cryonics is a technology that consists of gradually but rapidly lowering the body temperature of people declared legally dead until the temperature of liquid nitrogen is reached.
The technique must be started within half an hour of death, at which point decomposition stops.
A person kept in such conditions is considered a “cryopreserved patient” and not really “dead”.

Can one hibernate while alive?

Hibernation is only permitted post-mortem, but before brain death, cryopreservation from the living is not legally permitted even in cases of terminally ill patients.
Cryonics professionals, however, argue that it would be preferable to cryopreserve a patient before the disease can cause such damage that he or she dies.

How does cryopreservation work?

As soon as the heart stops beating and brain death is declared, technicians intervene to mechanically restore ventilation to the lungs and blood flow to the brain.
At this point the body is immersed in freezing water to be transported.
Before bringing the body to -196 degrees Celsius, the temperature of the liquid nitrogen, the blood is replaced by a substance that protects against the main contraindication of the technique, the freezing of water in the cells.
The necessary “cryoprotective” solution is injected intravenously to prevent the cooling process that would break the cell walls.
The body is then immersed in liquid nitrogen and brought to a temperature of -125 degrees centigrade and, after three hours, to the final temperature of -196 degrees.
The storage takes place upside down in Dewar vessels, insulating tanks that contain liquid nitrogen and prevent heat conduction.
The staff of the centre is in charge of frequently changing the liquid nitrogen indefinitely.

Preserving the body or just the brain?

It is also possible to use the head-only conservation procedure known as neuro conservation, which consists of conserving only the brain.
It is based on the hope that in the future it will be possible not only to revive cryopreserved bodies, but also to grow or clone new bodies in which to store hibernated brains.
The brain is kept in its natural place, the skull: the head is cut off from the rest of the body at the seventh cervical vertebra.
Here too, after a gradual drop in temperature, the head is placed in a small dewar container and immersed at -196° for long-term storage.

On what assumptions is human hibernation based?

The possibility of cryopreservation is based on three main hypotheses, but at the moment they have never been confirmed by science:

  • an individual’s memory and personality remain intact within the structure of the brain even when its activity is interrupted (after clinical death).
  • Cryopreservation procedures in no way affect the brain structures responsible for memory and personality.
  • It will be possible in the future to restore the brain capacity of cryopreserved brains.

At the moment there is no technique to bring hibernated people back to life.

However, scientists who practice it are convinced that resuscitation will be possible because:

  • Some biological samples have been cryopreserved, kept at liquid nitrogen temperature (stopping their decomposition) and brought back to life. These include whole insects, certain types of eels, many types of human tissue (including brain tissue), human embryos and some mammalian organs.
  • The capabilities of molecular biology and nanotechnology point to a future where we will have technologies that can repair the damage caused by ageing, disease and freezing.
  • However, it is not known whether information about memory and personality can remain in brain structures for a long time.

In 2016, steps were taken when a rabbit brain was able to hibernate and thaw without apparent damage, as can be read in the “Journal of Cryobiology” .

What are the cryopreservation centres?

At the moment there are only three centres in the world where cryonics can be performed on human beings: Alcor, in Arizona, the cryonics organisation with the highest number of subscribers.
The Cryonics Institute near Detroit was founded by Robert Ettinger, the “father” of cryonics.
The KryoRus, born in 2006 in Russia.
They all have long waiting lists for access.

Hibernation in Europe

There are no cryogenesis centres in Europe, but human hibernation is neither prohibited nor permitted. Only that the law provides for a 24-hour observation period after cardiac arrest in order to dispose of the body, but to avoid decomposition it is necessary to bring the body to -90° within half an hour of death in order to prepare it for hibernation.
He then decides to hibernate and must travel to the United States or Russia before dying.

The costs

In the United States the figures are between 80 and 200 thousand dollars.
The most expensive service is that of Alcor, which asks 200 thousand dollars (about 186 thousand euros) for the whole body and 80 thousand for the brain alone.
Cryonics, on the other hand, has variable rates, all under 100 thousand dollars.
In Russia, Kriorus asks 36 thousand dollars for the whole body and 18 thousand for the brain.