What It Is:
The immune system theory of aging is that the rate of aging is largely controlled by the immune system. As we age, the numbers of critical cells in the immune system decrease and become less functional. Starting before age 20, the thymus (which produced certain immune cells) begins to shrink.
How These Changes Affect the Body:
The immune system is important in keeping our bodies healthy. Not only does it protect us against viruses and bacteria, it also helps to identify and remove cancer cells and toxins. As we age, the potential for these elements to cause damage in our bodies increases.
Sources: Aging Under the Microscope; National Institutes of Health, National Institute of Aging.
