[Kim Jaeho's Life Story]<253> How to Protect Health Created by Cells

원본보기 아이콘

Our bodies are made up of tens of trillions of cells. Few people are unaware of the fact that our bodies consist of such a vast number of cells. Since these cells are co-living entities sharing a common fate with us, it is easy to think that they live with us for a lifetime. However, are people well aware that the lifespan of cells is generally much shorter than that of a person, and that countless cells die and are newly created to fill the spaces left by dead cells even while we are alive?

The lifespan of cells is generally shorter when the environment in which they work is harsh. For example, mucosal cells and white blood cells on the surface of the stomach or small intestine have the shortest lifespan of about 1 to 5 days, and skin cells also have a relatively short lifespan of about 2 weeks, which is why we often experience peeling skin. Platelets live about 10 days, red blood cells about 4 months, liver cells about 300 to 500 days, bone cells about 10 years, and the longest-living cells such as brain cells, lens cells of the eye, and heart muscle cells are known to live until a person dies if they are not damaged.

The reason why the lifespan of cells varies depending on the type of cell can be examined from the perspective of cell damage and repair. Each cell contains about 6 billion biomolecules called DNA, which is the minimum unit of the cell. It is known that up to one million DNA molecules can be damaged in a single day during our daily lives. Damaged DNA must be repaired to normal for cells to function properly.

However, if some cells sustain so much DNA damage during their activity that it is more efficient for the cell to die and be replaced by new cells rather than repairing the damaged DNA, our body makes this choice. This is the reason why the lifespan varies depending on the type of cell.

There are many other causes of cell death, which can be divided into two types: 'necrosis,' where cells die due to external factors, and 'apoptosis,' where cells self-destruct according to a programmed genetic program inside the cell. External factors causing necrosis include toxic substances, injury, infection, and interruption of blood supply. When cells undergo necrosis, inflammation occurs, which can cause additional pain or damage inside the body.

Unlike necrosis, apoptosis is a process where cells self-destruct according to a genetic program prepared inside the cell, often referred to as 'suicide.' Apoptosis plays an important role in maintaining health by removing old cells whose lifespan has ended, unnecessary cells, or unhealthy cells, and it is characterized by leaving no harmful substances around. In adults, it is known that 50 to 70 billion cells die by apoptosis daily, while in adolescents, 20 to 30 billion cells die this way.

If apoptosis does not function properly, serious problems can arise. If cells that should be removed are not eliminated, they can transform into cancer cells. Conversely, if apoptosis occurs excessively and too many cells die, the shortage of normal cells can cause organs or tissues to malfunction, leading to neurodegenerative diseases such as Alzheimer's disease or Parkinson's disease.

To maintain health, our bodies must first keep tens of trillions of healthy cells at an appropriate number without decreasing, allowing them to function normally. This requires minimizing the death of cells and ensuring that the spaces left by dead cells are filled by newly created cells. For this to happen, cell regeneration must be well maintained.

Cell regeneration, like apoptosis, is controlled by genes prepared inside the cells and occurs in two ways. The first is mitosis, where one cell divides into two genetically identical daughter cells. The daughter cells produced by mitosis are completely identical to the original parent cell in terms of DNA, function, and genetic information. Mitosis is observed in most cells such as skin cells, muscle cells, and liver cells.

The second form of cell regeneration is for cells that cannot regenerate by mitosis. First, stem cells divide by mitosis to increase their number, then differentiate into various types of progenitor cells. A representative example can be found in hematopoietic stem cells in the bone marrow. Blood cells such as red blood cells, white blood cells, and platelets do not undergo mitosis themselves, so hematopoietic stem cells divide by mitosis and then differentiate into red blood cells, white blood cells, and platelets.

This method of cell regeneration, where stem cells first divide and then differentiate into progenitor cells, is also found in brain cells. Since brain cells do not undergo mitosis, it was believed until 20 years ago that once brain cells die in adults, they never regenerate. However, it has been confirmed that neural stem cells in the hippocampus of the brain divide by mitosis and then differentiate into brain cells and non-neuronal cells.

Thus, countless cells in our bodies die or get damaged, and even without our knowledge, damaged cells are repaired to normal or self-destruct, and the spaces left by dead cells are replaced by new cells to maintain our health. If too many cells die or are damaged, making repair and regeneration difficult, it becomes hard for us to maintain health.

Therefore, to maintain optimal health for a long time, it is necessary to reduce cell necrosis and damage while ensuring proper cell repair and regeneration. This lifestyle improvement is achieved through Newstart (refer to Life Story Part 6), which creates an environment where the best doctor encoded in our body’s genes can work well by correcting unhealthy habits.

The first of Newstart’s eight components is a life diet that involves eating a variety of plant-based foods including fruits, vegetables, and grains in their whole form without selective eating of specific foods. Along with this, it is important to reduce the intake of sugar?which causes many problems when consumed excessively?as well as processed or refined bad carbohydrates, saturated fats, trans fats, salt, and alcohol.

Additionally, practicing the remaining Newstart components?exercise, water, sunlight, temperance, air, rest, trust, and love?is also important.

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