Aging and the Immune System

The immune system of human beings (as well as that of other mammals and birds), is composed by two important groups of lymphocytes: 

• T-cells that are differentiated in the thymus gland, and
• B-cells that are differentiated in a pouch-like cavity (or bursa) in birds. Mammals do not posses this cavity, but the name of the cells stuck.

During the puberty period, the thymus gland becomes smaller and smaller until almost disappears in adults. Without the presence of this gland, the T-cells are not well or not at all differentiated. The production of their colleagues, the B-cells, also begins to decrease. When the production starts diminishing of those cells in the bone marrow that are the precursor cells of the T- and B-cells, the bone marrow is less capable to properly perform cellular divisions. This means that the immune system becomes increasingly weaker, which might explain why people are much more sensitive to infections when they’re coming closer to the end of their lives.

From a certain age, the risk of developing an auto-immune disease, which means a condition where healthy cell in the body are attacked by the innate immune system, starts to increase. An example of such an auto-immune disease with a high prevalence among the elderly, is arthritis. In people suffering from arthritis, the cells of their own immune system begin to attack the cells that constitute the lining of the joint cavities, which causes inflammation and a steady decline in joint flexibility. This is often accompanied by pain and swelling of the joints.

Now, what can you do to prevent or counter this decline in immune function with age?

The immune system declines with age and that fact can not (yet) be changed. But you can try to make this decline as little as possible. There are several ways to naturally boost your immune system. Some of the most obvious ones are:

• Sleep and rest well: The functioning of the immune system is affected by sleep and rest. Sleep deprivation often results in a compromised immune system.
• Eat well: Like most systems of the body, the immune system depends on proper nutrition. It is known that both mal- and over-nutrition are associated with problems of the immune function. Some foods and herbs that positively affect the immune system are: fresh fruits and vegetables, ginseng, garlic, sage, hyssop and even honey.
• Go out and move: Both moderate exposure to sunlight and exercise are good for the immune system. The vitamin D and increased blood flow positively affect the immune function.