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Filthy friends and the rise of allergies

0. 16 April 2005

0. Garry Hamilton

0. Magazine issue 2495

It is not disease-free living that has sent asthma and allergy rates soaring but, as New Scientist discovers, the answer still lies in good old muck

AS THE mother of a child with severe allergies, Jana Robertson knows only too well that sometimes even constant vigilance isn't enough. Recently her 16-year-old son Ian, who is allergic to several foods including dairy products and peanuts, was planning to go to a pizza restaurant with friends. A few days in advance, Jana tracked down ingredient lists for everything her son would be eating on his night out. She had been checking ingredients ever since he was rushed to hospital at 11 months of age after suffering a severe reaction to soy formula.

This time everything was fine - or so she thought. But on the way home from the pizza parlour Ian complained of itchiness. When his forehead and lips began to swell his parents rushed him to hospital where doctors pumped him with epinephrine and intravenous fluids. He was in the early stages of anaphylactic shock, a ...

The complete article is 3726 words long in the New Scientist.

Notes on Article.

PROTECTION BY INFECTION?

The author notes that research now indicates that ‘contact with the hordes of benign microbes encountered by the body on a daily basis – deemed largely irrelevant by immunologists in the past – may be an essential step on the infant immune system’s road to healthy maturity. Likewise they suggest that the shift to a western life style may have short circuited this development by cutting off the body’s contact with certain microbes. The question now is which ones.’

Researchers are now looking at the microbes found in untreated water and dirt in unpolluted areas.

The evidence – children on farms have far less allergies – as do children ‘who drink unpasturised milk’ and have more contacts with cows – the stomachs of children are colonized much more quickly with a wider range of microbes. The presence in the gut of lactic- acid producing lactobacillus and bifidobacilus - as well as microscopic worms - seems to be particularly more common in those with less allergies. In January 2006 Joel Winstock and his team at the University of Iowa cured 21 out of 29 cases of Crohn’s Disease by dosing children once every 3 weeks for 24 weeks with a sports drink containing 2,500 pig whipworm eggs (a worm that cannot survive as an adult in a human). Worm killing medications likewise seem to create more allergy reactions. Endotoxin, ‘a potent immune stimulatory molecule associated with many bacteria commonly found in dirt and animal faeces’ also seems to ward of allegies.

However a hurdle obstructing research is that it is considered unethical to expose children experimentally with different bacteria.

The ‘rapid rise and peculiar distributions (of allergies) strongly suggests that environmental factors play a major role. Allergies are far more common in most western countries than in the developing world and more common in cities than in rural areas. … ‘ the dust mite theory is losing ground – as are other pollutants…

Instead we are now looking the immune system and microorganisms.

1980s studies showed that infants that caught measles were much less likely to get allergies in later life. In 1989 David Strachan at the London School of Hygiene and Tropical Medicine coined the name ‘hygiene hypothesis’ – meaning ‘modern immune systems were under rimed because of the dramatic reduction in serious childhood diseases.’

This theory is now revised – and focuses on Helper T Cells (CD4) as these seem able to stop the allergic reaction. These regulate the use or non use of killer T-Cells. CD8 , In 2005 Cezmi Akdis at the Swiss Institute of Allergy and Asthma Research in Davos found killer T cells were more common in allergy sufferers and helper T-cells in non-allergy sufferers.

My note - CD$ and CD8, Helper and Killer, T-Cells have long been known to be changed from one to the other in the body as needed, with the total number of both remaining constant.