Pesticides in produce and drinking water may be playing a role in the
increasing prevalence of food allergies, according to a new study.
Researchers
looked at 2,211 people and found those in the top 25% for urine
concentrations of chemical dichlorophenols -- used to chlorinate tap
water and keep pests off produce - were also 80% more likely to have a
food allergy.
"Adults can develop food allergies even though
they're not kids anymore," says allergist and study author Dr. Elina
Jerschow. "Adult allergies to foods are on the rise. That certainly
includes shellfish and fish allergies, but also peanuts. We don't know
what influences this development. But having been exposed to
dichlorophenols in our study suggests there could be some
link."Researchers believe dichlorophenols may alter the composition of
healthy bacteria growing in the human gut, which plays an active role in
immune system functioning.
It's the "hygiene hypothesis" - that
allergies result from too few exposures to microbes in our contemporary,
sterile environments - with a twist: the anti-bacterial environment
might also be found inside the intestines.
The study, published
Monday in the journal Annals of Allergy, Asthma and Immunology, doesn't
confirm that pesticides necessarily cause allergies or vice versa, but
it does indicate a possible association.
"Pesticides, and
insecticides in particular, are inherently toxic to human health," says
Dr. Kenneth Spaeth, director of the Occupational and Environmental
Medicine Center at North Shore University Hospital in Manhasset, New
York.
"This has been known for a long time in regards to large
exposures. However, it is only in recent years that the harmful effects
of low-level exposure from pesticides have begun to be revealed."
