A study, recently published by the New England Journal of Medicine, and written up into an article for AFP Relaxnews, suggested that children who grow up in contact with farm animals have stronger immune systems than those who do not.
The subjects of the study were the children of two similar farming communities — the Hutterites, who live in South Dakota, and Amish families in Indiana. The latter group is well-known for their shunning of modern technology and preference for simple, non-mechanized methods of farming. They tend to live and work on their own family farms, making use of horses to provide the muscle for heavy work.
The former community is less well-known, but shares close roots with the Amish. They are also descended from Germanic immigrants and base their lifestyle around farming. Like the Amish, they drink raw dairy milk, forbid animals to enter their homes, breastfeed their babies and have their children vaccinated.
Despite all of these similarities, it has been found that the children of the Hutterites (over 20%) suffer a much greater extent from conditions such as asthma while Amish children have exceptionally low rates of asthma (around 5%). It is thought that around 10% of American children, as a whole, suffer from the disease.
There is a key difference between the traditions of both communities, which is now believed to account for this difference. While Amish farms are small, and labor is carried out by farm animals and family members, Hutterite farms are much larger, communal projects, which make use of industrial farming machinery to do the heavy work.
This difference is important because it affects how much contact each family member has with the farm animals. Unsurprisingly, Amish children are in regular contact with farm animals, whereas Hutterite children are generally not.
Carole Ober, co-author of the study, and professor and chairman of human genetics at the University of Chicago, said that the link between growing up on a farm and a reduced risk of asthma was discovered over a decade ago. Thanks to this discovery, made by her colleague Erika von Mutius, she has now been able to narrow down the potential reasons for the link.
The link between asthma and dust has long been established, and this was obviously going to be of interest to the researchers. They found that dust found in Amish homes was richer in microbial products than the dust in Hutterite homes. Ober explained that neither community’s homes were dirty or particularly dusty, but that the difference in the characteristics of dust could be accounted for by the fact that Amish homes are closer to their barns. Amish children tend to run barefoot between the barn and the house throughout the day. Hutterite children, meanwhile, are relatively isolated from the farming.
This is important because it indicates that the microbes from farm animals, brought into the household on dust particles, serve to bolster a child’s immunity towards asthma. A young child’s immune system is exposed to tiny microbes and figures out how to fight it off at an early stage. This was reinforced by blood tests carried out on 60 children, half of the Amish, half of the Hutterite. These showed that the Hutterite children lacked neutrophils — blood cells for fighting infections — when compared with the Amish children.