If you want to maximise your chances of remaining free of bacterial
and viral infection, and given the prevalence of
malnutrutrition, a comprehensive micro-nutritional support programme
is a good starting point. But you can do more. Many micronutrients
play an essential role in immune function (at least 20, according to
Professor Ranjit Chandra at John Hopkins), but some may be more
important than others.
The immune system can be divided into two distinct sub-systems; the
innate and the acquired immune systems. The acquired immune system is
the one with the memory function, and is involved in immunisation,
allergy and auto-immunity. Once the acquired immune system has learned
to recognise an enemy (after an initial infection or after
vaccination), it remembers the enemy's characteristics. On second
exposure to the threat the memory cells recognise it, and generate an
immune response involving highly specific weapons such as antibodies.
This is a powerful, sophisticated and highly specific system, but it
is slow to mount and often insufficient to protect the host against
the first onslaught of a virulent bacterium or virus.
The very complexity of the acquired immune system can cause problems.
In autoimmune disease the acquired immune system confuses an element
in the body with a pathogen which it partly resembles, and attacks the
host's own tissues (as in rheumatoid arthritis, Multiple Sclerosis,
Systemic Lupus, Hashimoto's thyroiditis etc). In allergy, the acquired
immune system over-reacts to a stimulus such as animal dander or a
species of pollen, and causes the well-known symptoms of allergic
conjunctivitis, rhinitis or asthma.
The innate immune system is rather more basic. In evolutionary terms
it is much older than the more sophisticated acquired immune system.
It is less specific; and its key components are macrophages and
Natural Killer (NK) cells. Broadly, these patrol the body and look out
for anything that doesn't belong there. If macrophages spot a
bacterium they swallow it whole and try to digest it. If NKcells
recognise a virally infected cell or a cancer cell in the body they
will kill it so that it cannot produce more viruses, or replicate.
Unlike the acquired immune system, the innate immune system is
generally in a state of high alert. It springs into action the moment
it recognises the presence of a pathogen. It is our first line of
defence, while the acquired immune system is the second line. As the
numbers of antibiotic resistant bacteria in our environment continue
to increase, and the flu pandemic approaches, it makes good sense to
ensure that your innate immune system is working as effectively as
possible. But as with the acquired immune system, there is persuasive
evidence that this first line of defence is too often in disrepair,
due again to malnutrition.
As with the immune system overall, therefore, a comprehensive
micronutrient support programme is a good foundation. Onto that
foundation you can add a second layer of very specific innate immune
support agents. They include vitamin D, the trace element selenium,
the plant extract beta-sitosterol, and the 1-3, 1-6 beta glucans
derived from yeast, or, more expensively, from mushrooms such as the
Click here for Hazel Courteney's Beta Glucan
article Aug 2008