Wednesday, May 03, 2006

Obsession with avoiding health risks is unhealthy

One fifth of all Americans has asthma or other allergies. More Americans than ever before say they are suffering from allergies. Allergy is among the country's most common, yet often overlooked, diseases.

And the picture is similar in other developed countries. Allergies are increasing among the populations of the affluent Western world, but they are relatively rare in poor countries. Children, in particular, seem to be more and more prone to allergies in rich nations.

Allergies are often considered a minor ailment, but the truth is that they can be very serious, and sometimes fatal.

Although allergies have a genetic component, a shift in the human gene pool is an unlikely explanation for the increased prevalence of allergies, because it would require several generations and a much longer time.

A plausible hypothesis to explain this increase is that our immune system has weakened, because of excessive hygiene and sterilization.

Basically, allergies are an overreaction of the immune system to practically harmless substances (the ‘allergens’) that should not cause a reaction. They are a disease of the immune system.

The immune system's role is getting rid of any organism that should not be in our body, from microscopic parasites to viruses, from cancer cells to bacteria to fungal spores. Aids occurs when the immune system is not capable of carrying out its function. Allergy is the contrary: it develops when the immune system is too sensitive and performs too much.

Why should allergies be increasing? A theory proposed, the Hygiene Hypothesis, says that inadequate exposure to genuinely harmful agents leads to immune dysfunction. Under normal circumstances, the immune system is exposed to various viral, bacterial and other challenges, getting strengthened after successful defenses. Today's over-cleanliness and phobias of germs have minimized these opportunities.

Supporting evidence is ample. Children who have had early infections manifest less tendency to allergies. Populations in which parasitic infestation is common show lower levels of hay fever and asthma. People who have had measles have fewer allergies, as do children who have multiple siblings and therefore more infections in childhood.

New Scientist magazine reported a discovery that microorganisms found in dirt influence maturation of the immune system. The lack of connection with these organisms through soil may be the reason why allergies, bowel diseases, chronic fatigue and other immune disorders are now reaching epidemic proportions.

This is to me one of the classical cases of defeating the object.

Parents are particularly prone to this kind of obsession with protecting their children from any possible risk, as the furore in the UK about MMR vaccine's alleged link with autism has shown, leading to decrease in vaccination and increase in diseases.

But it is a common trend.

The problem is that we obviously cannot live in a risk-free environment, and we should instead learn to accept and live with the risks, and perhaps develop a more intelligent understanding of risk assessment, based on reason rather than emotion.

How does all this relate to the issue of animal experimentation?

I think there's a lesson to be learned from the allergies case.

There was a time when people sacrificed animals to the gods (tragically, they still do in some religions and in certain parts of the world), in the hope that the sacrifices would deliver them from evils.

The times have changed, but the hope that sacrificing somebody else, someone who cannot defend himself, will save us is still present.

Animal experimentation is the heir to the ritual sacrifice. And similarly it is founded on an attitude which, rather than accepting risks and developing a rational method to control them, relies on an emotionally charged hope of protection and salvation by risk-displacement, by transferring the risks on someone else.

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