The immune system is usually seen as our defence against infections. However if we want to support it best we should see it as much more than this, indeed as a key part of our internal housekeeping.
We can start by seeing it as a vast array of linked mechanisms designed to distinguish substances that should not be in the body, and then to prepare these for removal.
Why is this so important to us? The main target of the immune system is proteins and their larger fragments (peptides), as well as other complex molecules. These targets become known as antigens. However they are the same kind of substances that cells use to communicate with each other. Our healthy functions would be impossible if internal communications were disrupted by agents that should not be there. So our bodies expend huge resources to keep the channels clear.
When we look at where disruptions to our internal communications can come then we can see that infections are only one source. There are two constant and major sources of antigens into the bloodstream and circulating fluids.
- Our food. By definition this made up of foreign materials, and we would suffer great harm if food went straight into our tissues. We rely on a healthy digestive system to make food safe. Our digestive juices not only sterilise our food and reduce infection from this source, but render large antigenic molecules into small safe building blocks (eg amino acids and simple sugars).
- The internal contents of our own cells. Proteins inside a cell belong in there. Mostly they have no role in the body fluids and become antigens if they get out. Cells die and are recycled constantly. This is normally done very rigorously so that internal contents are pre-digested before the cell membrane is breached, a process known as apoptosis. Illness or severe tissue damage can disrupt apoptosis and many forms of immune disease are autoimmunity to our own intracellular contents.
The main role of the immune system is to guard against antigenic junk from any source. As well as gobbling it up it provides a very sophisticated mechanism to flag up anything that slips into the body tissues, so that it can be disposed of by other means.
Essentially therefore the immune system regulates our internal environment. It determines our health. It is also individual: my immune system is as unique as my fingerprint – it has my name on it!
However because they are complex, immune responses can go wrong. Many modern health conditions, especially if they are long term and severe, involve some degree of immune disruption, particularly autoimmunity, when our immune system targets our own tissues. We should understand the immune system as well as possible so as to develop herbal strategies that may help when it goes wrong.