Why Do People Become Allergic, And Why Are Allergies On The Increase?

by Jane Thurnell-Read

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 dont 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 sufferers 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 mothers 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 babys immune system has the same emphasis as the mothers 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 childs 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.