Immune System
The immune system defends the body against invaders like bacteria, viruses, toxins, cancer cells, and foreign tissues by generating specialized cells and antibodies that eliminate these harmful substances.
With aging, however, the immune system's responsiveness diminishes, resulting in increased vulnerability to diseases. Moreover, in older individuals, flu shots and other vaccines may not be as effective or provide protection for as long as they typically would in younger individuals.
In autoimmune diseases, the immune system erroneously targets and damages healthy body tissues. Additionally, with a decline in the number of functional immune cells for repair and surveillance, the body becomes more susceptible to cancer due to its diminished capacity to detect and rectify cellular mutations and abnormalities.Í
After the age of 40, the immune system becomes less effective in the following ways:
- Reduced ability to differentiate itself from foreign substances, increasing the risk of autoimmune diseases.
- Slower macrophage activity against bacteria and cancer cells, which may contribute to elevated incidence of infections and cancer. Macrophages are cells that engulf and kill foreign invaders, including cancerous cells.
- T-cells react slower to antigens or foreign invaders that they encountered before, resulting in less potent immunity attained from prior infection or vaccination.
- Fewer white blood cells (leukocytes) are produced in response to foreign invaders, thus impairing immune responses and immunity formation.
- Diminished production of complement proteins in response to pathogenic infections. Complement proteins are important in supporting the function of other immune cells and ensuring a coordinated immune response.
- Although antibody production in response to foreign invaders remains largely intact, these antibodies become less effective. This also explains why vaccines become less efficacious with aging.