Winter is a time when many people succomb to coughs , colds, flu and sore throats. Normally the immune
system will prevent unwanted invaders such as viruses and bacteria from entering the body or destroy
them before they have chance to spread. However, if the function of the immune system is impaired, an
organism can enter the body undetected and spread to cause infection. We should therefore ensure that
our immune systems are functioning efficiently if we want to avoid illness.
Many things can affect immune function, such as diet, exercise, mood and stress. Some of the warning
signs of a depressed immune system include :
Disordered sleep (too much or insufficient)
Loss of interest in enjoyable activities
Moodiness or depression
Excessive muscle soreness
Poor concentration, lack of mental energy
Altered appetite
Frequent injury or illness
Lack of physical energy.
There are a number of things which can be done to improve immune function and help protect against
infection. An important one is to avoid excessive stress (often easier said than done!) or introduce ways
of relieving stress such as meditation, regular exercise (in moderation!), having a massage, a relaxing
bath, a relaxing passtime etc. Stress suppresses the production of white blood cells and can lead to the
inhibition of the thymus gland. The workload of the immune system can be lessened by reducing the
number of micro-organisms entering the body via good hygiene habits. Substances should also be
avoided which reduce immune activity, such as drugs (including alcohol and tobacco!).
 |
 |
 |
 |
 |
 |
 |
 |
immune system. Some foods are high in nutrients
which are vital to maintaining the body’s defences.
The following table summarises the most
important vitamins and minerals for the immune
system and lists some sources.
| Nutrient |
Function |
Richest Sources |
| Vitamin C |
which inhibits viral growth)
destroy certain viruses.
carcinogenic nitrate compounds, which can occur after consuming nitrates in foods (eg in fertilizer residues, preservatives, or in smoked food.) |
Kiwi fruit, blackcurrants, strawberries, watermelon, peppers, parsley and dark green leafy vegetables. NB : smoking significantly increases vitamin C requirements. |
| Vitamin A |
Antiviral properties |
Red and yellow fruits and vegetables such as carrots, sweet potatoes, peaches, apricots and pumpkins and also dark green leafy vegetables such as spinach, broccoli, curly kale, watercress. (also found in hard cheese, eggs and liver.) |
| Vitamin B6 |
pathogens.
T-cells that fight pathogens entering the body. |
Brewer’s yeast, wheat bran, marmite, lentils, pulses and green vegetables. |
| Iron |
|
Whole grains, nuts, seeds, pulses, green leafy vegetables, seaweed. Also animal kidneys, liver and shellfish. |
| Selenium |
immune cell cannot efficiently copy the cells that it produces in response to a repeated infection.
|
Shellfish, brazil nuts, wholegrains and cereals, red swiss chard, garlic, molasses, turnips, mushrooms. |
| Calcium |
defeat pathogens.
destroy certain viruses. |
Spinach and dark green leafy vegetables, brazil nuts, almonds, seaweed and seeds. Also eggs, fish and dairy products. However dairy products also contain a lot of saturated fat, which is proinflammatory and detrimental to the immune system. NB : A diet high in animal protein increases the loss of calcium from the body. |
| Magnesium |
Required for :
|
Seaweed, dark green leafy vegetables, fish, pulses, nuts and seeds, marmite, wholegrain cereals. |
| Zinc |
maturing T-cells.
|
Wholegrains, seaweed, seeds (especialy pumpkin seeds), nuts, pulses, oysters, kidneys, sardines, crab, whelks. |
: asparagus, broccoli, carrots, cauliflower, garlic, mushrooms, brussel sprouts, onions, pumpkin,
peppers. They have high levels of antioxidants to help combat damage by free radicals. In
addition, they have strong antiviral, antibacterial and antifungal properties as well as being natural
antibiotics.
Some foods depress the immune system. Sugar inhibits the activity of the white cells, that digest
pathogens, for up to 5 hours after eating it. Caffeine, in coffee and tea, inhibits the absorption of
vital nutrients in addition to directly suppressing the immune system. Green tea, however, has
been found to stimulate immune function and should be substituted for the caffeinated, black
Chinese version.
The immune system is closely associated with the health of the colon. The natural balance of
bacteria in the colon can easily be upset, both by an excess of simple sugars and also by taking
antibiotics. Many bacteria produce natural antibiotics, which act against viruses, bacteria and
fungal infections. If medicinal antibiotics are taken they damage some of these friendly bacteria,
along with the target bacteria. The yeast, Candida albicans, can then get out of control and
proliferate. In so doing it inhibits immune action by decreasing the production of white blood cells.
Overgrowth of Candida albicans can be resoved by adopting a strict diet that excludes all sugars
and includes natural antibiotics and antifungals such as garlic and onions. Probiotics can be used
to recolonize the gut with friendly bacteria in the form of live, unsweetened bio-yoghurt, rich in
Lactobacillus acidophilus and Bifidobacteria.
It might seem more convenient to take a multi-vitamin pill to obtain vital nutrients. However, fruit
and vegetables also contain fibre and hundreds of other beneficial components as well as vitamins
and minerals. In addition, nutrients obtained from fruit and vegetables are more effectively
absorbed by the body than the synthetic alternatives. Increased consumption of fruit and
vegetables is also very beneficial for other aspects of health such as the heart and circulatory
system, the digestive system and can help prevent some forms of cancer.
The kitchen can be a source of powerful natural remedies. Many of the pungent, warming spices
can help to ward off colds and flu and assist in relieving symptoms. In hot countries, spices have
traditionally been used in cooking as an internal disinfectant to overcome the dangers from impure
food. Home-made curries, chilli and other spicy dishes can therefore be a good way of fighting
infections and avoiding illness.
Garlic is my favourite herb. It is a tasty addition to food but also has a huge range of medicinal
properties. The healing properties of garlic have been known for thousands of years. Its use in
ancient Egypt was documented 4500 years ago when a clove of garlic was given each day to the
workers building the pyramids to keep up their energy and ward off contagious diseases such as
flu and colds. In World War I garlic was used to fight typhus and dysentery and was used
externally as an antiseptic and on battle wounds to ward off septic poisoning and gangrene. Dr
Albert Schweitzer used garlic to combat typhus and cholera and Hippocrates used it to treat lung
infections.
Particular properties which make garlic an ideal weapon for combating winter bugs are its immune-
stimulating action and its antiviral and and antibacterial activity. A smelly compound called allicin is
formed when raw garlic is cut or crushed. Allicin has been found to have antibiotic properties.
Studies have shown garlic to have an antibiotic action against a wide range of microbes.One
researcher noted that garlic has the broadest spectrum of any known antimicrobial substance. It is
antibacterial, antifungal, antiparasitic, antiprotozoal and antiviral. It is used as an antibacterial
agent in many countries such as Japan, China and Poland. In the former Soviet Union it is known
as “Russian penicillin”. Raw garlic also increases the action of natural killer cells, thus boosting the
function of the immune system.
However, if you are unlucky enough to get a cold, garlic is also decongestant and helps to break
down and expel mucus. It was once commonly used to treat whooping cough. The volatile oils,
which have an antibacterial action, are excreted via the lungs making garlic effective at clearing
respiratory infections.
Garlic has many other useful properties, particularly for the cardiovascular system. Its warming
qualities dilate the blood vessels increasing circulation. It also lowers blood pressure, reduces
cholesterol levels in the blood and thins the blood, thus lowering the risk of strokes.
Garlic has to be raw to kill bacteria and boost immune functioning. Cooked garlic retains the ability
to lower blood cholesterol, thin the blood and act as a decongestant and expectorant. Processed
forms, such as garlic paste and dried or powdered garlic are not as beneficial as fresh. Daily
consumption of 1 – 2 cloves of fresh garlic can help prevent and fight infections.
For those who dislike garlic, onions share similar properties, although they are not as potent as
garlic. Onion is an old cold remedy, taken raw, in soup, roasted or made into a syrup. Onions
were at one time hung up as a protection against infectious diseases because it was believed that
they absorbed poison. Pasteur discovered onion’s antibacterial properties in the mid-1800s.
cold symptoms by thinning mucus and helping it to be expelled more easily, thus clearing the
airways. It also cleans out the sinuses. This action is mainly attributable to capsaicin, the
pungent component in chilli. Capsaicin has also been shown to block the bronchoconstriction
caused by cigarette smoke and other irritants. Chilli may therefore be beneficial for people with
asthma or those with hypersensitive airways.
Chilli also reduces levels of cholesterol and triglycerides in the blood, stimulates the circulation
and discourages blood clots. Capsaicin has been shown to cause a reduction of a
neurotransmitter called substance P in nerve cells. This substance relays pain sensations to
the central nervous system. Thus it short-circuits the perception of pain. It can be used in an
ointment as a local analgesic.
Capsaicin and the other chemicals responsible for the hot taste dissolve in alcohol and also in
fat. So for those who have the tendency to be a little “generous” with the chilli powder, a few
sips of milk or beer will relieve the burning sensation more effectively than water or soft drinks.
Other warming spices such as ginger, mustard, cinnamon and cloves also have a beneficial
action. All four have a decongestant action, helping to thin mucus and clear phlegm from the
respiratory passages. Mustard was also traditionally used externally in plasters applied to the
upper chest and throat to clear an imminent cold.
Cinnamon and cloves also have an antiseptic action, inhibiting various organisms including
viruses and can therefore act as a preventative against colds and flu. Clove oil has been used
traditionally as a germicide and antiseptic to kill pain from decaying teeth. Eugenol, which
makes up 85-90% of the oil acts as a temporary anaesthetic. Cloves can also be used to treat
laryngitis and sore throats.