The Book of Secrets - Deepak Chopra [72]
Apoptosis is programmed cell death, and although we don’t realize it, each of us has been dying every day, right on schedule, in order to remain alive. Cells die because they want to. The cell carefully reverses the birth process: It shrinks, it destroys its basic proteins, and then it goes on to dismantle its own DNA. Bubbles appear on the surface membrane as the cell opens its portals to the outside world and expels every vital chemical, to finally be swallowed up by the body’s white cells exactly as they would devour an invading microbe. When the process is complete, the cell has dissolved and leaves no trace behind.
When you read this graphic account of a cell sacrificing itself so methodically, you can’t help being touched. Yet the mystical part is still to come. Apoptosis isn’t a way to get rid of sick or old cells, as you might suppose. The process gave us birth. As embryos in the womb, each of us passed through primitive stages of development when we had tadpole tails, fishlike gills, webbing between our fingers, and most surprisingly, too many brain cells. Apoptosis took care of these unwanted vestiges—in the case of the brain, a newborn baby forms proper neural connections by removing the excess brain tissue that we were all born with. (It came as a surprise when neurologists discovered that our brains contain the most cells at birth, a number which gets whittled down by the millions so that higher intelligence can forge its delicate web of connections. It was long thought that killing off brain cells was a pathological process associated with aging. Now the whole issue must be reconsidered.)
Apoptosis doesn’t end in the womb, however. Our bodies continue to thrive on death. The immune cells that engulf and consume invading bacteria would turn on the body’s own tissues if they didn’t induce death in each other and then turn on themselves with the same poisons used against invaders. Whenever any cell detects that its DNA is damaged or defective, it knows that the body will suffer if this defect is passed on. Fortunately, every cell carries a poison gene known as p53 that can be activated to make itself die.
These few facts barely scratch the surface. Anatomists long ago knew that skin cells die every few days; that retinal cells, red blood cells, and stomach cells also are programmed with specific short life spans so that their tissues can be quickly replenished. Each dies for its own unique reason. Skin cells have to be sloughed off so that our skin remains supple, while stomach cells die as part of the potent chemical combustion that digests food.
Death cannot be our enemy if we have depended upon it from the womb. Consider the following irony. As it turns out, the body is capable of taking a vacation from death by producing cells that decide to live forever. These cells don’t trigger p53 when they detect defects in their own DNA. And by refusing to issue their own death warrants, these cells divide relentlessly and invasively. Cancer, the most feared of diseases, is the body’s vacation from death, while programmed death is its ticket to life. This is the paradox of life and death confronted head on. The mystical notion of dying every day turns out to be the body’s most concrete fact.
What this means is that we are exquisitely sensitive to the balance of positive and negative forces, and when the balance is tipped, death is the natural response. Nietzsche once remarked that humans are the only creatures who must be encouraged to stay alive. He couldn’t have known that this is literally true. Cells receive positive signals that tell them to stay alive—chemicals called growth factors. If these positive signals are withdrawn, the cell loses its will to live. Like the Mafia’s kiss of death, the cell can also be sent messengers that bind to its outer receptors to signal that death has arrived—these chemical messengers are actually known as “death activators.”
Months after