The Causes of Human Aging

Throughout history, human beings have always been trying to overcome disease and aging.  What are the major reasons behind these two biggest challenges for human survival and longevity?

In the recent years, one of the major breakthroughs in bioscience is the discovery of stem cells.  Scientists have categorized all human cells into two groups - "stem cells" and "specialized cells".  Stem cells, the primitive cells at the earliest stage of cell development and differentiation, are able to divide and self-renew, and differentiate into various specialized cell types to form tissues and organs such as heart, liver, brain, and lymphoid tissues.  On the other hand, specialized cells create the homeostasis (internal environment) which supports and promotes the growth of stem cells. Despite having different mechanisms, stem cells and specialized cells are interdependent and also very important for the metabolism and vitality in a living organism. 

Although manifested in different ways, disease and aging are both results of dysfunctional mechanisms of stem cells. Organ degenerations (e.g. epidermal cells) are generally induced by the failure of stem cells to proliferate, self-renew and differentiate into specialized cells for repairing and replacing organ- and tissue-specific cells. By restoring and improving the mechanisms of stem cells, mankind would be able to prevent and treat any kind of diseases, even delay aging and have true beauty.

Let us further analyze the mechanisms of stem cells to understand why they are so important.

Different types of stem cells are located in different tissues and organs of a living organism.  When the specialized cells are damaged or lost due to normal wear and tear, injury or disease, stem cells will renew themselves through cell division, differentiate into organ- or tissue-specific cells to replenish these cells, and maintain the normal functions of organs and tissues.  Specialized cells’ direct involvement in the body’s metabolism is manifested by the activities in the tissue and organs, for example, liver detoxification and bile secretion, cardiac contraction, and urinary function of the kidneys.  By continuously repairing and replacing specialized cells, stem cells play a vital role in maintaining the normal functions of the organs and tissues.

Under the external stimuli, not only specialized cells gradually degenerate and become less effective, stem cells are also damaged and fail to repair and replace specialized cells effectively.  Over time, as the count and activities of specialized cells are reduced to a certain extent, the overall functions of organs and tissues deteriorate and are manifested by aging and different types of chronic diseases (e.g. hypertension, high cholesterol, high blood sugar, etc.).
The current treatment of chronic disease or beauty therapies are directly acting on specialized cells or replacing their functions.  For example, most types of skin care products are acting directly on epidermal cells.  Although certain skin care products may be able to penetrate the inner skin layer to stimulate the stem cells and even renew skin cells, they are only acting on the skin cells which are only one type of the human stem cells. Only by repairing and enhancing the overall functions of stem cells, true beauty can be achieved from inside out.