The finding was published in Annals of Allergy, Asthma and Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI), and came from a team of experts led by Elina Jerschow, M.D., M.Sc., ACAAI fellow and allergist.
According to the researchers, high levels of dichlorophenols, a chemical used to chlorinate water and also used in pesticides, is linked to food allergies when it is found in a person's body.
Dr. Jerschow explained:
"Our research shows that high levels of dichlorophenol-containing pesticides can possibly weaken food tolerance in some people, causing food allergy. This chemical is commonly found in pesticides used by farmers and consumer insect and weed control products, as well as tap water."
Data of 10,438 people from the United States National Health and Nutrition Examination Survey 2005-2006 was analyzed for purpose of the study. Dichlorophenols was found in the urine of 2,548 subjects, but 2,211 were further observed.
Results showed that 411 of the 2,211 analyzed had a food allergy, and 1,016 had an environmental allergy.
Dr. Jerschow said:
"Previous studies have shown that both food allergies and environmental pollution are increasing in the United States. The results of our study suggest these two trends might be linked, and that increased use of pesticides and other chemicals is associated with a higher prevalence of food allergies."
Although drinking bottled water may seem less risky for developing an allergy than drinking water from the tap, the results from this research indicate that making the switch to bottled water may not be effective in preventing allergies.
"Other dichlorophenol sources, such as pesticide-treated fruits and vegetables, may play a greater role in causing food allergy," added Dr. Jerschow.
Between 1997 and 2007, food allergy increased by 18%, according to the CDC (Centers for Disease Control and Prevention).
A previous report, published in Journal of Allergy and Clinical Immunology, found that 7.5 million Americans have at least one food allergy, and young black children seem to be at the highest risk.
The most frequently reported food allergens are:
- tree nuts
What are the symptoms of a food allergy?Food allergy symptoms may be mild for some people and severe for others. For example, some individuals may experience a mild rash while others experience a life-threatening reaction called anaphylaxis, which can cause a rapid pulse, swollen throat, and loss of consciousness. People with this reaction should seek medical treatment immediately. If untreated, it may result in a coma or death.
The symptoms of a food allergy normally develop within a few minutes to a couple of hours after eating.
Mild symptoms include:
- isolated hives
- mild nausea
- itchy mouth
- stomach cramps
- dizziness or confusion
- hives all over the body
- repetitive cough
- shortness of breath
- pale or blue skin
- tight throat, trouble swallowing
- weak pulse
- swelling of tongue or lips
Written by Sarah Glynn