While the exact cause of allergies is not clear, many scientists believe that genetic factors in the allergic person and environmental factors act together in their development. Numerous studies have reported an association between genes that exert their effects predominantly in combination with environmental factors, e.g., cigarette smoke (Kabesch, 2006) or tobacco smoke (Diaz-Sanchez, 2006), to cause allergies.
At least some early life exposure to common household microbes and unpasteurized milk reduces our later risk of acquiring allergies. Allergic people can avoid triggering allergy symptoms by limiting the exposure to allergens. Healthy eating habits and exercise can further strengthen one's immune system and avert undesired effects.
Bacterial extracts have been reported as "modulators" of the
host immune system. In one study farmer's children and rural residents
were reported to be less likely to develop allergies than their
urban counterparts. Perkin and Strachan (2006)
proved that unpasteurized or raw milk consumption was associated
with significantly lower IgE levels and fewer allergy symptoms.
Several studies in human volunteers report that ingestion of probiotic bacteria (Lactobacillus,
bifidobacterium, eubacteria) or fermented milk products or exposure
to environmental mycobacteria are helpful in preventing allergies
(Matricardi et.al, 2003;
Schrezenmeier and Vresem,
2001; Adlerberth et
al. 1991). These different bacteria have a role in modification
of Th2 to Th1 immune response and induction of interferons (IFN-^g),
interleukins (IL-2, IL-12)
and allergen-specific IgG antibodies that antagonize IgE mediated
effects. (Matricardi et.al,
Although allergens are known to increase symptoms in allergic
individuals, early exposure to some of them, e.g., common environmental
microbes as fungal spores or bacteria in mattresses, carpets,
play grounds, unsanitary places, decreases the chances of developing
an allergy. The exposure to bacterial endotoxins and lipopolysaccharides
present in unpasteurized milk, yoghurt or fermented milk early
in life helps prevent the development of asthma and other related
allergies (Douwes et al.
2006). Similarly, the presence of an animal in the home has
been associated with decreased sensitization to animal allergens.
Infections with helminthes in early life reduced the risk of developing allergies. Mangan et al. (2006) proved in their animal model studies that infection with parasitic worms like Schistosoma mansoni in mice reduced respiratory allergic disorders by increasing the production of interleukins (IL-4, IL-10 and IL-13) and reduction of IL-5 levels. If a person has little or no exposure to helminth infections in childhood, Th1 cells will not be stimulated to produce the cytokines and interferons that help prevent the overproduction of IgE which results in an increased risk of developing allergies (Bell, 2002).
Thus some exposure to microbes, helminths, and unpasteurized milk in early life can reduce the probability of developing allergies.
Go To Beware of the Common Allergens
Special thanks to Deborah
Whitman for her invaluable help with this Discovery Guide
List of Visuals
- A cigarette will burn to ash on one end
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