As blood decays, so the cells die
If the blood has rotten 10 percentage then as many cells are not reformed. Only 90 percentage of the normal cells are reformed. If 20 percentage, then 80 percentage, if 30 percentage then 70 percentage. In short, new cells are reformed in inverse proportion to the decay of blood. What is worse, as the cells diminish in number, all the organs of human body weaken. They work feeble. The stomach, the pump, the brain, the eyes, the ears, and so on all don’t work full. That is to say, the organs work in proportion to the reforming rate of new cells.
Meanwhile, the older man grows, the more his blood decays.
It is because of his desire. Because he has been desirous and greedy for all his life, his blood decays by degrees as he grows older. Further, blood and cells are in feedback each other. The unsound cells reformed from the decayed blood bear the impure blood, and the impure blood gives birth to the unsound cells.
Therefore, as man grows older, the cells of his flesh, bone, and all organs diminish in number. It is because of the decay of his blood. Because his blood has decayed a lot, new cells are not reformed perfectly and his body falls short of the normal number of the whole cells. On this, he comes to have many wrinkles all over his body. Now that the reason for growing old is revealed obviously, we cannot use such expression as man grows old because of his age or time and tide.
The exact expression to be used is as following. “Man grows old not because of age but because of desire”