Old folklore wisdom stated that “A little dirt never hurt anyone,” or “Everyone must eat a peck of dirt before they die.” As so often proves the case, the knowledge of the pre-scientific world was based on common sense and observation.
Few parents today would tell a child to “Play outside and get dirty.” However, raising children in an antiseptic, germ-free environment may be creating health problems for them later in life.
The Hygiene Hypothesis
In November 1989, David Strachan, an epidemiologist, wrote an article in the British Medical Journal in which he proposed the existence of what came to be known as “The Hygiene Hypothesis.”
Dr. Strachan was studying the incidence of hay fever and eczema when he noticed that these allergy-based problems cropped less frequently in children who came from large families when compared with kids from single-child families.
He speculated that exposure to germs during early childhood gives the human body better protection against allergies.
Dirt Helps Skin Heal
Writing in The Telegraph, Murray Wardrop (November 23, 2009) reports that researchers in the United States have found a scientific explanation for the hygiene hypothesis. “Scientists have discovered that bacteria on the surface of the skin play an important role in combating inflammation when we get hurt. The bugs dampen down overactive immune responses, which can lead to rashes or cause cuts and bruises to become swollen and painful.”
By over-sanitizing their children, parents may be impairing the ability of the harmless bacteria to aid the healing process.
Dermatologist Professor Richard Gallo of the School of Medicine at University of California, San Diego led the research team that made discovery. The results have been published in the scientific journal Nature Medicine (November 22, 2009) and reported by BBC News (November 23, 2009) as showing that “a common bacterial species, known as Staphylococci, blocked a vital step in a cascade of events that led to inflammation.”
The bacteria “did this by making a molecule called lipoteichoic acid or LTA, which acted on keratinocytes – the main cell types found in the outer layer of the skin.”
Parent Lobby Group Welcomes Research
The British lobby group parentsoutloud.com says the research supports its view that an overabundance of government health and safety regulations has created an artificially cleansed environment around children.
The guiding force of the group is Margaret Morrissey, and she is quoted by The Telegraph as saying: “Parents have become so paranoid about their children playing outside and getting dirty that today’s youngsters are not enjoying a proper childhood.
“You cannot blame parents for this because they are constantly bombarded with advertising telling them they have to buy antibacterial products to keep their children clean and healthy.”
Morrissey blames living in an antiseptic bubble for tripling of the number of children developing food allergies.
In his research report Dr. Gallo writes that this view “is supported by clinical trials and experimental models in which exposure to microorganisms that were ubiquitous during mammalian evolutionary history, but are currently ‘missing’ from the environment in rich countries, will treat allergy, autoimmunity, or intestinal inflammation.”
Sources:
“Dirt Can be Good for Children, Say Scientists”. BBC News, November 23, 2009.
“Commensal Bacteria Regulate Toll-like Receptor 3-Dependent Inflammation After Skin Injury”. Nature Medicine, published online November 22, 2009.
Wardrop, Murray. “Children Should be Allowed to Play in the Dirt Because Being too Clean Can Impair the Skin’s Ability to Heal Itself, New Research Suggests.” The Telegraph, November 23, 2009.
Rupert Taylor - Rupert Taylor is the editor of a magazine that provides background to current events.
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