Immunity Gone Wrong
PUBLISHED: 15:11 22 October 2007 | UPDATED: 14:54 20 February 2013
More and more people are suffering from allergies in this country - why? The House of Lords Science and Technology Committee warned recently that allergies are reaching epidemic proportions in the UK. In the last 20 years, there has been a dramati...
More and more people are suffering from allergies in this country - why? The House of Lords Science and Technology Committee warned recently that allergies are reaching epidemic proportions in the UK. In the last 20 years, there has been a dramatic increase in the instance of allergies, giving the UK one of the highest rates of allergic disease in the world. The severity of the symptoms has also increased, so much so that a number of potentially life-threatening disorders, previously rare, are now much more common. Peanut allergy - the most common food allergy to cause fatal or near-fatal reactions - is one such. Ten years ago it was a rare disorder, yet it has since trebled in incidence and now affects one in 70 children in the UK. The latest estimates suggest that around 18 million people will develop an allergy at some time in their lives.
Allergic reactions are caused by substances in the environment known as allergens, which are harmless to most people but can cause significant symptoms in the body of a predisposed person. That person's immune system believes itself to be under attack so produces a particular type of antibody to attack the 'invading' material. This in turn triggers other blood cells to release histamines, and these together produce the symptoms of an allergic attack - typically sneezing, a runny nose, wheezing, shortness of breath, itchy and watery eyes or rashes - although these symptoms can all also be caused by factors other than allergy. Common allergens are pollen, house dust mites, moulds, pets, industrial and household chemicals, medicines and foods such as milk and eggs.
We don't start out with allergies, but develop them as a result of contact with the allergen. There are various theories for the rapid increase in allergies. Increased incidence of peanut allergy, for example, could be the result of more pregnant women eating nuts and sensitising their foetuses, or more children being introduced to nuts at an earlier age. There's also the possibility that Western society's increasing obsession with cleanliness is leaving children's immune systems with nothing to react against, causing it to respond inappropriately to 'safe' products. And, curiously, children with more siblings are less likely to develop hayfever than an only child. It's thought that children with more siblings experience more childhood infections, and that having infections somehow protects against allergy. Dirt and infections - maybe there's something to be said for the old adage about the benefits of eating a peck of dirt before you die.
The House of Lords Science and Technology Committee www.publications.parliament.uk/pa/ld200607/ldselect/ldsctech/166/16602.htm
Peanut allergy www.peanutallergyuk.co.uk