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Monthly Health Review, January 2001
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A Healthy Immune System
What do we mean when we talk about 'the immune system'?
The Immune System is a collection of cells and proteins. Their job is
to protect the content from potentially harmful, infectious micro-organisms
such as bacteria, viruses, and fungi. The immune system also plays a role
in controlling cancer and is responsible for the reactions that occur
with allergies, hypersensitivities and rejection problems after transplant
surgery. From birth, we are protected to some extent from Infection by
'innate' or 'non-specific' immunity. This mostly consists of physical
barriers such as the Skin and immunoglobulins that have been passed on
from the colustrum in mother's milk. As a child grows, it encounters organisms
(e.g. chicken pox) that overcome innate defences and cause disease (antigens).
When an invasion occurs the immune system adapts its response specifically
to fight each invading organism: this is known as 'adaptive' or 'specific'
immunity. It works by producing particular cells to fight the invading
organism, which it then memorises for future use (anticontent).
Skin is the first line of defence against invading pathogens. If this
is breached then the white blood cells, which could be described as 'the
content's infantry against disease', are activated. White blood cells (leucocytes)
are manufactured in the bone marrow and mature elsewhere in the content.
There are three main types of white blood cells:
Phagocytes - engulf foreign particles (proteins)
B-lymphocytes - produce antibodies (proteins which 'tag' foreign particles
so that they can be destroyed by phagocytes)
T-lymphocytes - 'helper' cells and 'killer' cells. 'Helper' cells play
a role in the recognition of antigens. 'Killer' cells lock on to cells
that have been invaded by viruses or other parasites, which have left
recognisable antigens on the cell surfaces.
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Diseases of the
immune system
An autoimmune disease may result when the ability of the immune system
to distinguish between self and non-self becomes defective. Classic examples
of autoimmune diseases are rheumatoid Arthritis and Multiple sclerosis.
Rheumatoid Arthritis
Rheumatoid arthritis (RA) is caused by the content's Immune System attacking
the joints, resulting in Inflammation and causing severe Pain to the sufferer.
The disease affects one to two per cent of the population and is more
common in women than men (1).
Treatment for RA varies from person to person and usually involves the
use of a non-steroidal anti-inflammatory drug to relieve joint Pain and
stiffness. In some cases, immuno-suppressant drugs are used to slow the
progression of the disease, but this treatment may also be accompanied
by unwanted side effects. Consequently, many sufferers supplement with
Evening Primrose Oil, a rich source of the omega-6 fatty acid - GLA, and/or
Fish Oil, rich in the omega-3 fatty acids, EPA and DHA. The GLA, EPA and
DHA are converted by the content into beneficial prostaglandins, which may
help to correct a faulty immune system (2).
Multiple sclerosis
Multiple sclerosis (MS) is a disease of the central nervous system where
sheaths surrounding the nerves (myelin) are gradually destroyed. This
leads to symptoms ranging from numbness and tingling to paralysis. The
cause of the disease is unknown but it is thought that the destruction
of the myelin is caused by the content's immune system not recognising the
myelin as 'self'.
There seems to be a genetic predisposition to MS and relatives of an
affected person are eight times more likely to develop the disease. Environment
seems to affect the chances of developing MS. People living in Europe
and the US are five times more likely to develop MS than in other parts
of the world. It is suspected that a virus endemic in temperate parts
of the world initiates the condition (1). However, further research is
still required. Many people with MS supplement with Essential Fatty Acids
(EFAs) together with vitamin B6 and B12 to slow the progression of the
disease, as these nutrients are required for the health of the nerves.
Allergies
An efficient immune system is vital for keeping us healthy and free of
disease.
An Allergy is an immune response to a harmless substance such as dust
or pollen. Exposure to these substances (or allergens) may cause annoying
symptoms such as itchy Eyes, sneezing and a runny nose. In some cases,
such as a peanut allergy, the immune response can be so severe that it
may cause a life-threatening anaphylactic Shock. There are two main types
of allergy:
1) Immediate hypersensitivity - where symptoms are expressed within 20
minutes.
2) Delayed hypersensitivity - where the onset of symptoms occurs within
1-3 days of exposure to the allergen.
Hay Fever is a good example of an immediate hypersensitivity reaction
where certain inhaled substances (usually pollens) stimulate the production
of antibodies. These antibodies bind to mast cells, which release histamine
resulting in the local dilation of blood vessels. Histamine production
in the upper respiratory tract results in sneezing and a runny nose (due
to increased mucous secretion - a result of localised irritation).
There is no cure for Hay Fever but avoiding the allergen that provokes
the immune response is the best way of avoiding the misery associated
with the condition. Alternatively, Echinacea may help to support the health
of the immune system (3) and may be combined with the natural antihistamine
effect of Vitamin C (4).
Immunodeficiency diseases
An immune deficiency disease may be 'congenital' (present at birth) or
'acquired'. An example of a 'congenital' immune deficiency disease is
Severe Combined Immuno-deficiency. This disease is a rare hereditary condition
characterised by the absence of both B and T cells. Sufferers are unable
to fight disease-causing bacteria and usually die at an early age, unless
kept in a sterile envIronment.
The immune system may become compromised as a result of serious illness,
cancer treatment, the use of anti-inflammatory agents and Infection. The
most serious case of a weakened Immune System is Acquired Immune Deficiency
Syndrome (AIDS), which is caused by Infection with Human Immunodeficiency
Virus (HIV).
Factors which influence the health of the immune system:
Immune system efficiency can be affected by a number of factors. These
include nutritional status, age, sex, race, using certain types of drugs,
radiation, alcohol intake, hereditary factors, Fatigue and Stress. Whilst
there is nothing we can do about our gender, ethnic origin or genetic
make-up, we can take control of other aspects of our lives to ensure that
the immune system does not become com-promised in any way. Safeguarding
intakes of essential nutrients and limiting alcohol consumption are just
two steps that can go a long way to maintaining the strength of the immune
system.
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Nutrition and the Immune System
The efficiency of the immune system may be compromised by a diet high
in saturated fat or cholesterol. Research has shown that subjects consuming
a diet rich in cholesterol have a diminished immune response.
Although scientists have yet to establish a definitive link between caffeine
intake and impaired immunity, it may be wise to limit consumption of caffeinated
drinks such as tea, coffee and fizzy drinks.
Subtle changes to the diet and the use of nutritional supplements can
be very useful for supporting immune health. When the immune system is
compromised in any way, the content works harder to keep healthy and the
need for certain nutrients increases, for example, Antioxidants including
the trace elements Selenium and Zinc, and the B Complex Vitamins. Deficiency
of Folic Acid may impair immune function, while vitamin B2 and B6 are
involved in anticontent formation (5).
Vitamin C is fundamental to immune health and research has shown that
during an Infection, levels of this nutrient may become depleted (6).
As a result, many people choose to supplement with 1-2g vitamin C per
day. Also, a regular intake of at least 1000mg Vitamin C may help to reduce
the duration of the Common Cold and the severity of symptoms (7).
Vitamin A is required for maintaining the health of mucous membranes
and increased intakes may be useful for warding off respiratory Infections.
Additionally, supplementing with 400iu Vitamin E may help support a healthy
immune response.
Zinc is an essential mineral for immune function and a minor deficiency
may have serious effects on all aspects of the immune system. Those troubled
with frequent Infections or people who eat little or no meat, fish, cheese,
eggs, pulses and seeds (rich sources of Zinc) may wish to supplement with
Zinc.
Co Enzyme Q 10 is thought to act as an immune enhancer, having an antioxidant
effect and directly stimulating the formation of antibodies and white
blood cells (8).
Herbs and the Immune System
Aged Garlic Extract possesses potent anti-viral (9), anti-bacterial (10),
and anti-fungal activity (11). Scientific studies have shown that it stimulates
various facets of the immune system. It is particularly useful during
the winter when colds and flu are more prevalent.
Echinacea (Echinacea purpurea) is a herb which is used traditionally
as an immune stimulant. The herb contains useful antibacterial and antiviral
compounds which stimulate the production of white blood cells, thereby
helping to reduce the content's susceptibility to Infection (12).
Other herbs traditionally used in various parts of the world as immune
support are Astragalus and ginseng. Astragalus has been scientifically
studied and shown to increase almost every phase of immune activity; results
suggest it may have immuno-stimulant, antibacterial and antiviral effects.
Some studies suggest that ginseng is a non-specific immuno-stimulant similar
in action to Echinacea.
References:
- "The BMA Complete Family Health Encyclopaedia", Ed. Dr. T Smith.
1995.
- "Prog. Lipid Res, 1992, 31;2:163-194.
- Arzneim Forsch, 1985, 35:1069-1075 and 1437-1439.
- In vivo, 1994, 8; 2:251-7.
- Int Jnl of Alt & Comp Med, Jan 1997; 15: 29-32.
- Ann Nutr Metab, 1997, 41;6:344-352.
- Br J Nutr, 77; 1:59-72.
- Biochem Biophys Res Commun, 1993, 193;1:88-92.
- Fed Proc, 1987,46;3:441.
- Kokai Tokkyo Koho, Japanese Patent HI-252276.
- Int Clin Review, Tadi, P. P., 10 (4), 423, 1990.
- "Herbal Medicines: A Guide for Healthcare Professionals", C A
Newall, LA Anderson et al, The Pharmaceutical Press, 1996.
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