As we get older, our immune system changes in a number of ways. It often becomes both overactive and less effective, leaving the body in a state of chronic inflammation. This inflammation, sometimes referred to as inflammaging, can cause damage to cells and tissues. As a result, bodily functions, including those of the brain, work less and less well.
A major cause of these inflammatory responses is a piece of DNA ending up in the wrong place within the cells. Normally, this DNA is neatly in place, but with ageing it sometimes gets into the wrong location, as if the body thinks it has an infection. This keeps the immune system constantly on high alert, which is ultimately harmful to the tissue.
At the same time, the immune system also weakens. This phenomenon is called immunosenescence. Immune cells grow older and less effective, making them less able to fight diseases and clear away debris such as damaged cells. In the brain, this causes special immune cells, microglia, to perform their tasks less effectively. This contributes to the onset and progression of neurodegenerative disorders, such as dementia.
These insights show that better understanding and addressing age-related changes in the immune system is important to counteract brain ageing. Research is therefore focussing on ways to reduce or prevent inflammaging and immunosenescence. This can improve the quality of life at a later age.
For anyone consciously working towards healthy ageing, this research highlights just how far our immune system influences our brain health.
Source: Reason
