The incidence of asthma is increasing in Western countries worldwide especially Australia, New Zealand and the UK. In the past decade, there has been such an increase in asthma in Australia and New Zealand, for instance, that it’s now the most common reason for children being admitted to paediatric hospitals in both countries.

In New Zealand, approximately 15 per cent of the adult population and 20 per cent of children under 15 are affected by asthma. In Australia, around 12 per cent of all Australians have reported asthma as either a recent or long-term condition in the previous 12 months and childhood asthma has the same high prevalence as in New Zealand with up to 20 per cent of Australian children being diagnosed with asthma.

Asthma is also very expensive. In the 2000-2001 financial year, health expenditure on asthma in Australia was $693 million or 1.4 per cent of the total health expenditure in that year. From 1994 to 2000, there was a 21 per cent increase in expenditure on asthma, the greatest increase being on pharmaceuticals.

However you look at it, asthma is a major health issue in this part of the world. So it’s well worth looking at natural ways to prevent and treat this common condition.

The theory of asthma

Given the rising incidence of asthma, the burning question becomes: what causes it?

Types of asthma

Inherited asthma (atopy)

Atopy is a genetic problem manifested by a difficulty metabolising essential fatty acids such as omega-3 (or omega-6) — the anti-inflammatory fats. Research suggests atopic asthma and dermatitis are associated with an enzyme defect in lipid metabolism, meaning the person has a greater requirement for essential fatty acids.

Environmentally triggered asthma

This form of asthma is a bronchial hypersensitive reaction to various external stimuli such as chemicals, cold air, exercise, infection and emotional upset or stress.

Asthma can also be considered either a “dry” (inflammatory/allergic) asthma or a “wet” asthma in which the bronchial constriction is triggered by the increased mucus produced by a cold or ‘flu. The wet asthma needs to be treated a little differently; stimulating the immune system to protect against bronchial infections is of the utmost importance to manage the condition.

We know asthma is a hypersensitivity disorder featuring a spasm of the bronchial tubes. In asthmatics, the bronchial tubes are blocked by the swelling caused by inflammation, or by bronchial spasms or mucous plugs. One interesting theory to explain the increase in asthma in the Western world involves two interacting components of the immune system: Th1 and Th2 (T-helper lymphocytes 1 and 2).

Th1 is the part of the immune system that responds to infection, while Th2 rises with allergies and inflammatory conditions. These two components are in a constantly shifting relationship with each other (and the environment). If one goes up, the other goes down. /p>

This has meant that with the improvements in hygiene of recent times there has been less call on Th1, so there has been a rise in Th2. Our children are more sanitised than they have been in the past (or in societies where asthma is a rare condition). When children play in the dirt and mud, the exposure to different microbes activates the Th1 component (and lowers Th2) in the development of immunity.

With Th1 being activated, children are much less likely to get the chronic inflammatory diseases associated with the activation of Th2, such as asthma. The immune system of children living in excessively clean environments does not develop correctly due to lack of natural exposure to germs and microbes. At the same time, vaccinations, while they may protect to some extent against the infectious diseases, can exacerbate allergies and inflammation (by increasing Th2).