Aging, also simply called "senescence," is an inevitable, cumulative, intrinsic, and progressive biological process that, over the years, leads to the loss of bodily functions. It's important to note that it is not a disease in itself, but rather a risk factor for many other age-related illnesses.
Have you ever wondered how this happens ? To understand it, we need to know what cellular senescence is. It's quite interesting: when your body's cells have accumulated enough damage, they try to protect your body by preventing themselves from multiplying further. This is called cell division arrest. Interestingly, these cells are also very resistant to dying on their own ( apoptosis ), and because of this same damage, they become dysfunctional. Furthermore, they infect other healthy cells nearby. Like zombie cells, these are precisely the senescent cells. The so-called hallmarks of aging , which we will discuss later, are involved in this entire process.
Now, senescent cells aren't entirely bad for your body, as they appear during tissue repair processes (during wound healing) and during development. In these cases , they are eliminated by your immune system . HOWEVER, if they begin to accumulate excessively in your tissues, organs, and systems, that's where problems arise. For example, the accumulation of these cells is linked to diseases such as Alzheimer's, arteriosclerosis, osteoarthritis, and type 2 diabetes mellitus (Figure 1). This makes aging a complex process.
