Your immune system is crucial in maintaining your health—so it's important to keep it in good order. But how do you do that? People talk about boosting immunity as if it were a task similar to building muscles or reducing blood cholesterol. Hundreds of ads for supplements and other products promise to boost immunity. But keeping your immune system in good shape is a complicated task. "How do I boost immunity?" is really the same question as "What can I do to stay well?" Here are the answers to 13 key questions about immunity.
How does the immune system fight disease?
Because war is a handy metaphor for the human body's reaction to disease, science writers like to describe the immune system in militaristic terms—the body's department of defense. But unlike the Armed Forces, the immune system has no headquarters or commander-in-chief. And its operations are usually swifter and more efficient than any army's could be.
Rather than "making war," your immune system is really more like an immigration service: a highly differentiated cellular bureaucracy that supervises your biological commerce with the outside world, sorts through billions of pieces of information about incoming materials and takes routine action as required. Only occasionally does it declare an emergency.
The immune system's basic task is to recognize "self" (the body's own cells) and "nonself" (an antigen—a virus, fungus, bacterium or any piece of foreign tissue, as well as some toxins). To deal with nonself or antigens, the system manufactures specialized cells—white blood cells—to recognize infiltrators and eliminate them. We all come into the world with some innate immunity. As we interact with our environment, the immune system becomes more adept at protecting us. This is called acquired immunity.
What are the parts of the system?
Among the primary components of the immune system are a variety of white blood cells. These constitute a communications network that helps organize the immune response.
Most people are surprised to learn that the skin, including the mucous membranes, is among the most vital components of immunity. The skin not only forms a wall against intruders, but actually alerts the white blood cells if the wall is breached by invading organisms (through a wound, for instance). The protection afforded by the intact skin is why it's nearly impossible to catch a disease from a toilet seat, for example.