Allergies are on the increase - a third of the population believe that they suffer from allergies, and even though some of these people may be mistaken, everyone agrees that eczema, asthma, hay fever, irritable bowel syndrome, etc. are now more and more common. So, what has happened?

It is often unclear why a person has a tendency to be allergic or intolerant to a range of substances. Medical practitioners talk about 'atopic individuals' - atopic means 'out of place'. To the unknowing this sounds like a medical diagnosis, but in fact all it means is: You have a tendency to have allergies; you may have several different symptoms caused by your allergic reactions; this often runs in families; we don't know why. Describing someone as an atopic individual is not saying anything the person does not already know about themself!

Genetic Predisposition

Allergy problems undoubtedly do run in families, so there may be a genetic component, although the exact mechanism is not clearly understood. Some small genetic mutation can cause the immune system to be triggered more easily, so that family members sharing this mutation will all have a tendency to allergic reactions, although not necessarily to the same substances, but this does not explain the rise in the incidence of allergies in recent years.

Severe Virus Infections

A severe virus infection can lead to damage to the immune system, so that the individual is more likely to develop allergies in the future. Again, although this may explain why someone has allergies, the incidence of virus infections is not on the increase.

So we have to look elsewhere to explain the rise, and there are several completely different possibilities.

Parasites

One allergy theory now being proposed is that the lack of the proper enemies (liver fluke, tapeworms, etc.) has led to an idle immune system finding inappropriate work in allergic reactions. There are many antibodies produced in the body to protect it against invasion by harmful organisms. IgE antibodies deal effectively and quickly with the extreme danger of infection by large parasites, such as tapeworms. Parasites' effect on health can be devastating, so over the years individuals with efficient IgE mechanisms have lived to reproduce and pass on their genes at a greater rate than people with a less efficient IgE mechanism. The IgE antibodies are also involved in allergic and hypersensitivity reactions, so people with these inherited efficient IgE mechanisms are more likely to suffer allergy problems than people who have inherited a less efficient system. This super-charged immune system was a plus for an asthma sufferer's distant ancestors inhabiting a world with many life-threatening parasites, but now leads to a 'trigger-happy' immune system firing off inappropriately.

Other practitioners (notably Hulda Clark in 'Cure For All Diseases') take the opposite view, and see many allergy symptoms as being a reaction to an infestation of parasites.

Excessive Cleanliness

The obsession with the danger of 'germs' is thought to have led to an increase in allergies. Much of this obsession with cleanliness seems to be driven by the media and advertising. Headlines about 'killer bugs', and advertisements that claim a product kills even more germs have led many people to buy more and more products to wipe out these dangerous enemies. A view now gaining ground among many researchers and some doctors is that a certain level of dirt is good for us, particularly during infancy and early childhood when the immune system is maturing.

T-helper cells in the immune system recognise foreign antigens and then secrete substances to activate other cells to fight the invader. In pregnancy the T-helper cells that attack invaders directly without producing antibodies (Th1 cells) are less active, as these could lead the mother's system to reject the foetus. This means that the T-helper cells that are responsible for antibody reactions (Th2 cells) are more prominent. These are the ones that are involved in allergic reactions. The new baby's immune system has the same emphasis as the mother's had during pregnancy. It is believed that the exposure of the very young to some level of 'dirt' is beneficial in that it helps to rebalance the immune system to emphasise the T-helper cells that are not involved in the allergy process.

In an excellent article ('New Scientist' July 18th 1998) Garry Hamilton talks about 'the gentler side of germs'. If the young are not exposed to 'dirt', the immune system does not go through this rebalancing process, and a tendency to allergy can result. Linda Gamblin in 'The Allergy Bible' cites several medical research projects, which support the idea of allowing children to be exposed to dirt and minor infections to help protect against allergies.

Vaccination

Our children are now being vaccinated against a bigger and bigger range of diseases. While some of these are serious, many are mild illnesses that were once considered part of a normal childhood. Many alternative practitioners consider that these childhood illnesses help to prime the immune system so that it is better able to cope with a whole range of illnesses later in life. This view is not accepted by most of the medical profession, and indeed it would be difficult to prove. However, there is some evidence that vaccination alters the ratio of T-helper cells and T-suppresser cells. This would be likely to have an effect on the vaccinated child's susceptibility to allergy reactions. It is also known that most vaccines stimulate the branch of the immune system that is concerned with the more extreme immune reactions to invaders such as parasites ('New Scientist' July 18th 1998).

Ubiquitous Presence Of Some Foods

Before the advent of freezers and airfreight most people ate local foods in season. Now most fruit and vegetables are available all year round, so that our systems are exposed to the same foods continually without respite.

There has been a dramatic increase in people experiencing soya allergy, since soya has become a common ingredient in many processed foods. In Europe and North America rice allergy is relatively uncommon, whereas in Asia where it is consumed more frequently it is much more common.

Technological Developments

Developments that make modern life more comfortable have also led to an increase in allergies. With the advent of air conditioning, central heating and wall-to-wall carpeting house dust mites and moulds such as alternaria have an ideal environment in which to thrive. Modern offices with sealed windows mean that everyone is exposed to the perfumes worn by other people. The increasing use of plastics, formaldehyde, benzene etc. have led to all of us being exposed to an amazing variety of chemicals.

Contamination By Environmental Pollutants

The chemicals in diesel fumes are known to damage the outer membranes of pollens. This means that when the pollen is breathed in, the pollen proteins are immediately in much closer contact with the delicate membranes in the mouth, nose and lungs than they would be if the pollen had not been damaged in this way.

It has now also been suggested that the immune system is reacting to some harmless substances because they have been contaminated by environmental pollution: the immune system does not recognise the food, for example, if it has molecules from tyre rubber attached to it. These molecules sometimes appear similar to enzymes produced by parasites and so the immune system attacks the 'parasite'.

Although more and more evidence is accumulating for a role for environmental pollutants, this does not explain why New Zealand, which is relatively unpolluted, has one of the highest incidences of asthma in the world.

Electro-Magnetic Pollution

An increase in electro-magnetic pollution has run parallel with the increase in allergies. The scientific jury is still out on the danger of mobile phones, power lines, etc., but many people are becoming more concerned about our constant exposure. People who are sensitive to computers, etc. often also show many symptoms typical of allergic individuals. In some cases correcting this sensitivity to electro-magnetic sources, results in all or most of the adverse reactions disappearing. (I recommend health kinesiology for this.)

Stress

The pace of life is quickening all the time: modern technology gives us more possibilities and many of us want to experience as many of these as we can. A survey found that half of the 950 young people in their 20's interviewed said that they would feel a failure if they did not own a home by 26, were not married by 27 and not both rich and parents by 29. Many of the interviewees said they were prepared to sacrifice a healthy diet and way of life to achieve this. These expectations and pressures are not conducive to long-term health and can also lead to stress and allergies. Pre-packaged, processed foods eaten in front of the television, too much alcohol, too little fresh air and exercise all take their toll.

Sometimes particular traumatic events can explain a particular allergy. One of my clients was allergic to wool and tea. She told me that when she was a small child she had pulled a cup of hot tea on to herself. At the time she was wearing a wool sweater, and the tea soaked into the sweater and burnt her very badly.

Diet

It is now well known that bottle-fed babies are more likely to be prone to allergy problems than breast-fed ones. Sudden or early weaning can contribute to the problem too.

Sadly the modern diet may be abundant in calories, but there is more and more evidence that it is low in some important nutrients. People are eating more pre-processed foods, which may be nutritionally compromised.

Soil is becoming depleted of some minerals, because they have long been taken up by plants grown in the soil. If the mineral is not in the soil, it cannot be in the plant, and so it is not available in the foods we eat either.

It is unlikely that there is one simple answer as to why people are allergic, intolerant or sensitive in general or to particular substances. Research is still being carried out in this fascinating area. Fortunately with the tools that are available it is not necessary to know why someone has allergy problems in order to be able to detect and correct them.

Jane Thurnell-Read is a writer and researcher on health, stress, alternative medicine, and happiness. Visit her web site http://www.healthandgoodness.com for tips and information on how to live a happier, healthier life no matter how busy you are.