Running Head: ENVIRONMENTAL CAUSES OF FOOD ALLERGIES
Environmental Causes of Food Allergies
Carli M Yokoi
7 December 2013
University of California, Davis
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ENVIRONMENTAL CAUSES OF FOOD ALLERGIES
Abstract
This paper will discuss the role of the environment in influencing the development of
food allergies. I will research the epigenetic factors involved in food allergies, specifically
focusing on those that significantly increase the risk for being diagnosed. The symptoms and
current treatments available will also be included in order to provide background information on
the seriousness of food allergies.
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ENVIRONMENTAL CAUSES OF FOOD ALLERGIES
Environmental Causes of Food Allergies
Food allergies are on the rise and this occurrence poses the question as to what food
allergies are actually caused by. According to Discovery Channel (Channel, 2013), "15 million
Americans have food allergy, a potentially life-threatening disease. Almost 6 million of them are
children. Every 3 minutes, a food allergy reaction sends someone to the emergency department."
In the womb, children are influenced by what their mother eats and does. Because of this
influence, it is vital that precautions are taken in order to minimize the risk of food allergies. As
an often overlooked disease, food allergies are more dangerous than ever. The prevalence of food
allergies is on the rise, causing distress and death to children and adults worldwide. The
environmental factors influencing the development of food allergies need to be further
investigated in order to work towards putting an end to this phenomenon.
An Overview of Food Allergies
During an allergic reaction, the immune system registers a particular food consumed as
being dangerous and thus enacts a response. Immunoglubin E (IgE) antibodies are discharged,
which causes chemicals to be released into the bloodstream. Histamine, one of the chemicals that
was released in the blood, forces the body to experience varying symptoms such as
lightheadedness, stuffy nose, coughing, wheezing, hives, nausea, vomiting, blood pressure
decrease, and possibly death. The term anaphylaxis includes any life-threatening symptoms that
can lead to death.
Reactions to food allergies are not consistent, making the symptoms experienced
extremely dangerous and unpredictable. A person could experience hives the first time, but
anaphylaxis the next. One such story was noted in The New York Times (Thernstrom, 2013):
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ENVIRONMENTAL CAUSES OF FOOD ALLERGIES
"...B.J., who ate a dessert that turned out to contain peanut while on a family trip to Mexico to
celebrate his high-school graduation...The family didn’t have an EpiPen, because they thought
the worst that could happen was that he would get some itchy hives, as he had before. They still
thought he would be O.K. when the medical team arrived, but then the doctor said, “I’m sorry,”
and pulled a blanket over his head and everything was over." No one in B.J.'s family knew that
he would die from his allergy. If they had, they would've had the opportunity to better prepare
themselves for disaster, such as bringing an EpiPen and keeping it readily available at all times.
Because the number of people affected by food allergies continues to grow, various hypotheses
have been formed as to explain why.
Causes
Genetics alone cannot be responsible for the rapid increase in food allergies (Tan, T. H.,
Ellis, J. A., Saffery, R., & Allen, K. J., 2011). A combination of factors contribute to this disease
and recent research has suggested a relationship between food allergies and epigenetics.
Epigenetics refers to the environment and its influence on modifying what is carried on to each
generation.
According to Susan Prescott and Richard Saffery (2011), factors that could potentially
cause food allergies include "progressively cleaner environments, more pro-inflammatory
Western style diets, environmental contaminants and pollutants, and maternal transmission of
antigens during pregnancy or soon thereafter. Most notably, there is now evidence that these
environmental exposures can modify early immune gene expression through potentially heritable
epigenetic changes" (p. 3). As food allergies increase in occurrence, more is being discovered
about what might be causing it.
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ENVIRONMENTAL CAUSES OF FOOD ALLERGIES
The hygiene hypothesis states that society has become too clean, thus removing the
exposure children get to bacteria at an early age. Without this exposure, it is thought that
children's immune systems do not develop proper defenses. Whether or not a child grew up with
pets and other siblings is also a factor.
During pregnancy, diet is a crucial part of determining the presence of food allergies. A
study was completed that showed evidence of increased risk of developing food allergies and
asthma for a child when a pregnant mother consumed hydrogenated oils (Thernstrom, 2013).
According to The New York Times article by Melanie Thernstrom (2013), a study by the
American Academy of Allergy, Asthma and Immunology showed that food allergy risk also
increases if babies are given rice or corn at the age of 6 months (Nwaru et al.,2012). Genetically
modified foods, such as soy, have been proven to cause elevated levels of food allergy. Smith
(2007) stated that in 1999, scientists in the United Kingdom revealed that there was a 50%
increase in reactions to soy products in just one year alone. To genetically modify a certain food
is to add a virus, bacteria, or genes to it. In doing so, a new protein is created that has potential to
cause allergic reactions. Horizontal gene transfer occurs when genes move from the DNA of one
species to the DNA of another. This action combined with the process by which genetically
modified products are made led Smith (2007) to the conclusion "that years after people stop
eating GM soy, they may still be exposed to its risky protein, which is being continuously
produced within their intestines." Genetically modified foods have the possibility of heightening
the effects experienced from certain allergens or even containing and introducing entirely new
ones. A protein found in genetically modified soybeans was shown to respond to the antibody
IgE, which is responsible for the symptoms of allergic reaction and anaphylaxis. Based on the
results of a study by HealthNuts, Tan, Ellis, Saffery, and Allen (2011) concluded that
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"introducing egg into the diet at either 10–12 months or after 12 months was associated with
higher risks of egg allergy." Clearly, diet is a factor in influencing food allergy risk.
Hong and Wang (2012) stated that "Air pollution exposure during the first year of life
was associated with an increased risk of FS [food sensitization] at year 8." According to
Thernstrom (2013), children exposed to tobacco smoke, whether in the womb or in early years of
life, also have increased risks for food allergies. Various studies completed, however, seem to
have conflicting results. This suggests that more factors are at work together to influence food
allergy development, such as genetics and other environmental causes.
Current Treatments
Food allergies continue to affect millions of people, yet the amount of people truly aware
of its implications seems to be only a handful. At this time, no cure exists for food allergies, but
studies are continuing to progress.
Avoidance is the only way to be sure one does not experience an anaphylactic reaction.
This involves taking special precautions when going out in public or merely eating at home.
Each and every single ingredient must be placed under scrutiny because even the tiniest bit of a
food could cause a reaction, depending on how sensitize a person is. For example, a peanutallergic child touching a playground that other children have touched after eating peanuts could
have devastating consequences. As awareness continues to grow, however, it is becoming easier
to live a normal lifestyle. Restaurants are now being required to accommodate food allergies,
specially training its staff and providing a list of ingredients used in meals. This is a small step,
but with food allergies on the rise, future problems are sure to be presented.
An anaphylactic reaction can be stopped if epinephrine is quickly administered. In order
for the epinephrine to work, it needs to enter the bloodstream as soon as possible. Doctors
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recommend EpiPens to be carried on the person with food allergies at all times. EpiPens have the
ability to be a life-saving treatment. There are cases, however, in which the reaction is too
severe, or the epinephrine was given too late. In such situations, death is inevitable.
Kari Nadeau, an associate professor of allergies and immunology at Stanford University
School of Medicine and Lucile Packard Children’s Hospital, is currently in the beginning stages
of research. Specifically, she is working on immunotherapy for children with food allergies. In
the trial, she would administer precise doses of a particular food that a child had an allergy to,
slowly increasing the doses each time. Over an extended period of time, Nadeau was able to
desensitize multiple children's food allergies. Nadeau and her team experienced a breakthrough
when they successfully desensitized a child to several allergens at the same time. Much like
taking medication, however, each child must regularly consume small doses of the food they
have become desensitized to (Thernstrom, 2013). Although this experiment is in its beginning
stages, its results hold promises for future research.
What does this mean?
Thernstrom (2013) stated that a particular study "led researchers to believe that food allergies are
about 70 percent genetic in origin and 30 percent environmental." These statistics show just how
important the interactions between genes and the environment can be. It is essential that society
takes note of this epidemic and takes steps to further the current knowledge of it. Children and
adults around the world continue to suffer, and with new research and developments currently
taking place, the environment's influences are sure to be addressed as well. It might be possible
to slow the progression of food allergies by controlling what we eat and what our children are
exposed to.
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References
Channel. (2013). An Emerging Epidemic: Food Allergies in America. <i>Discovery Channel
CME</i>. Retrieved November 18, 2013, from
http://www.discoverychannelcme.com/patient-education/food-allergies
Hong, X., & Wang, X. (2012, September). Early Life Precursors, Epigenetics, and the
Development of Food Allergy. <i>NCBI</i>. Retrieved November 18, 2013, from
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3439840/
Nwaru, B., Takkinen, H., Kere, J., Simell, O., Veijola, R., Ilonen, J., et al. (2012, November 22).
Elsevier Health. Timing of infant feeding in relation to childhood asthma and allergic
diseases. Retrieved December 6, 2013, from
http://download.journals.elsevierhealth.com/pdfs/journals/00916749/PIIS0091674912016
96X.pdf
Prescott, S., & Saffery, R. (2011, August). The role of epigenetic dysregulation in the epidemic
of allergic disease. NCBI. Retrieved November 18, 2013, from
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3156327/
Smith, J. (2007, May). Institute for Responsible Technology. Genetically Engineered Foods May
Cause Rising Food Allergies-—Genetically Engineered Soybeans. Retrieved November
18, 2013, from http://www.responsibletechnology.org/gmo-dangers/health-risks/articlesabout-risks-by-jeffrey-smith/Genetically-Engineered-Foods-May-Cause-Rising-FoodAllergies-Genetically-Engineered-Soybeans-May-2007
Tan, T. H., Ellis, J. A., Saffery, R., & Allen, K. J. (2011, July 19). The role of genetics and
environment in the rise of childhood food allergy. Wiley Online Library. Retrieved
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November 18, 2013, from http://onlinelibrary.wiley.com/doi/10.1111/j.13652222.2011.03823.x/full
Thernstrom, M. (2013, March 7). Can a Radical New Treatment Save Children With Severe
Food Allergies?. The New York Times. Retrieved November 18, 2013, from
http://www.nytimes.com/2013/03/10/magazine/can-a-radical-new-treatment-savechildren-with-severe-allergies.html?pagewanted=1&_r=2&&pagewanted=all