The background to the research
The researchers first used mice to see what was going on. They exposed them to farm dust and found that they did not suffer from the most common house dust mite allergy that affects most people. What was protecting the mice? Was there a secret ingredient in the dust? They found that there was a protein called A20 which kicked into action when the mice and humans were exposed to the dust. This is a vital component when allergies affect humans because it offers a sort of protection for the mucous membranes which overreact to allergens. When this A20 was in short supply or inactivated in the mice, they started to have allergic and asthmatic reactions.
Why farm children are protected
Research is still ongoing but a few things are emerging which give us a clue as to what is going on. They are not sure which bacteria in the farm dust stimulates an immune system response in the farm kids. City kids are apparently not getting enough farm dust, just petrol fumes and other toxins. They also have a reduced amount of the A20 protein which would protect them. This is why their reaction to allergens and asthmatic triggers are so unstable. According to the CDC (Centers for Disease Control and Prevention) in the USA, about 7 million kids suffer from asthma. Those suffering from allergic reactions to mold and pollen account for 17%. The majority of farm kids just do not figure in these statistics. Those that do suffer from allergies were found to have a mutation in their A20 gene which prevents them producing enough to prevent their allergies.
Amish children
The University of Arizona has conducted similar research on Amish farm kids in Indiana who grow up exposed to farm dust from hay, silage and cattle. These kids never or rarely need inhalers. Researchers are curious to know why the Hutterite people in South Dakota who also grow up on farms have a higher rate of asthma. They use more modern farming technology than the Amish and this may be a factor.
The hygiene hypothesis
There have been suggestions that urban kids are growing up in an environment which is too clean. This hygiene hypothesis could be one explanation as to why these kids are often subject to allergies and asthma. As the child’s immune system matures, it needs to respond to threats. Otherwise, it will never be fully effective in recognizing what may or may not be harmful. T This may be one explanation as to why asthma is reaching epidemic proportions as mentioned by Dr. Fernando Martinez, Director of the Arizona Respiratory Center, University of Arizona who has remarked, “Asthma is reaching epidemic levels in children, and 1 in 10 now need treatment for this debilitating condition.”
What is the way forward?
What is that active substance in the farm dust which kicks the A20 protein into action and gives kids protection? The answer could be in the dried-up cow manure lying round the farm. The bacteria may be found here which will open up new possibilities This is the question that researchers are determined to find the answer to. It will, eventually, lead to more effective medication for asthma and also pave the way for a vaccine. Allergy medications are likely to improve and be much more effective, but all this will take time. Featured photo credit: Pudge got his first asthma inhaler today/Thomas Widmann via flickr.com
