One reason given for aging is that, as you get older, some of your cells do not die as expected. These cells accumulate in the body and limit the growth of replacement cells. This delay in the death of aging and and removal of rather unhealthy cells is called senescence.
Research has shown that speeding up the death of these cells and their removal has led to longer life in mice. Drugs were used called senolytics to speed up the removal of these older cells. The result was that the mice appeared to have experienced a degree of reverse aging and their health improved, which also increased their longevity.
The health of the mice was also better. Their biological systems became more capable of fighting off disease. They performed better on exercise tests and their muscles did not deteriorate (sarcopenia) as fast. Their organs also continued to function better.
The process of senescence is currently believed to be a protection against cancer. But as the senescent cells continue to accumulate, the effect overcomes the ability of the immune system to destroy them. Senolytics has shown that their introduction into the body strengthens the immune system.
In cancer and some other diseases, substances are released that naturally help aging cells to live longer. They are called pro-survival and anti-apoptoptic (against normal programmed cell death).
One thing that often leads to death in seniors is that the cells that normally fight off disease – called T-cells lose their ability to do so. As your thymus gets older, it ceases to function as well, which means the training the T-cells get from their development in the thymus is not completed and they no longer can recognize harmful bacteria or infections.
When they cannot recognize harmful agents anymore, the body becomes subject to getting various diseases because the T-cells no longer attack the harmful agents. It is often these diseases that eventually take the life of the individual.
The use of senolytics on mice revealed several promising developments. Since the body begins to be affected even by a small accumulation of senescent cells, the experiments on mice removed these aging cells and the immune system improved.
The key to a valuable senolytic in humans is to which ones that can kill senescent cells without damaging normal healthy ones. They also must not stop the normal aging process of cells, but only kill those that refuse to die.
Although the science of senolytics is rather new, testing on humans has already begun. Some positive results have already been shown, but much more needs to be done to find senolytics that can be used to treat various diseases.
Several senolytics have already been ruled out because although they have helped destroy senescent cells, they have also have some rather serious side effects. New ones are in the early stages of testing, and researchers also continue to look for new ones that might be promising.
When you exercise, the mitochondria in your cells control cell activation. The exercise burns a lot of energy, and at the same time it helps to turn on the process of cell death among older cells. This process enables new cells to grow in their place, which enables a better functioning body.
