Uptil now we used to think that death means “Your heart stops beating, your brain shuts down” or the moment of cardiac arrest. Until fifty years ago, when CPR was developed, when you reached this point, you couldn’t come back. That led to the perception that death is completely irreversible.
But remember if I were to die this instant, the cells inside my body wouldn’t have died yet. It takes time for cells to die after they’re deprived of oxygen. It doesn’t happen instantly.
We have a longer period of time than people perceive.
When you become a corpse, when the doctor declares you dead, there’s still a possibility, from a biological and medical perspective, of death being reversed.
If left alone the cells become damaged. There’s going to be a time when you can’t bring them back. But nobody knows exactly when that moment is.
It might not just be in tens of minutes, but in over an hour. Death is really a process.
Death is, essentially, the same as a brain stroke. In stroke, blood flow stops from getting into the brain. Whether it’s because the heart stopped pumping, or there was a clot that stopped blood flow, the cells don’t care.
Brain cells can be viable for up to eight hours after blood flow stops.
If we can learn to manipulate processes going on in cells, and slow down the rate at which cells die, we could go back and fix the problem that caused a person to die, then re-start the heart and bring them back. In a sense, death could become reversible for conditions for which treatments become available.
If someone dies of a heart attack, for example, and it can be fixed, then in principle we can protect the brain, make sure it doesn’t experience permanent cellular death, and re-start the heart. If someone dies of cancer, though, and that particular cancer is untreatable, then it’s futile.
When you die, most of your cell death occurs through apoptosis, or programmed cell death. If your body is cold, the chemical reactions underlying apoptosis are slower. Making the body cold slows the rate at which cells decay.
But we’re talking about chilling, not freezing. The process of freezing will damage cells.
(Source: Erasing Death:The Science That Is Rewriting the Boundaries Between Life and Death.)
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