| Food
Allergies:
When Food Becomes the EnemyBy
Ray Formanek Jr (staff writer for FDA Consumer) Imagine
what it would be like if eating a peanut butter sandwich or some shrimp, or drinking
a tall glass of milk left you vomiting, gasping for breath, and furiously scratching
a fresh crop of hives. For some people with food allergies, that's reality.
A
food allergy, or hypersensitivity, is an abnormal response to a food triggered
by the immune system. While many people often have gas, bloating or another unpleasant
reaction to something they eat, this is not an allergic response. Such a reaction
is thought to not involve the immune system and is called "food intolerance."
Only
about 1.5 percent of adults and up to 6 percent of children younger than 3 years
in the United States--about 4 million people--have a true food allergy, according
to researchers who have examined the prevalence of food allergies.
It's
critical for people who have food allergies to identify them and to avoid foods
that cause allergic reactions. Some foods can cause severe illness and, in some
cases, a life-threatening allergic reaction (anaphylaxis) that can constrict airways
in the lungs, severely lower blood pressure, and cause suffocation by the swelling
of the tongue or throat.
An
estimated 150 Americans die each year from severe allergic reactions to food,
says Hugh A. Sampson, M.D., director of the Elliot and Roslyn Jaffe Food Allergy
Institute at Mount Sinai School of Medicine in New York City and a food allergy
expert. The
Food and Drug Administration's Center for Food Safety and Applied Nutrition has
made it a high priority to boost consumer and food industry awareness of food
allergens. As part of these efforts, the FDA is conducting food allergen education
programs for consumers and industry. The agency also is developing a strategy
for clear, easy-to-understand labeling of food allergens. Allergic
ReactionsFood
normally doesn't provoke a response from the human immune system, the body's defense
against microbes and other threats to health. In food allergies, two parts of
the immune response are involved, according to researchers at the National Institute
of Allergy and Infectious Diseases. One is the production of an antibody called
immunoglobulin E (IgE) that circulates in the blood. The other part is a type
of cell called a mast cell. Mast cells occur in all body tissues but especially
in areas that are typical sites of allergic reactions, including the nose, throat,
lungs, skin, and gastrointestinal tract. People
usually inherit the ability to form IgE against food. Those more likely to develop
food allergies come from families in which allergies such as hay fever, asthma,
or eczema are common. A
predisposed person must first be exposed to a specific food before IgE is formed.
As this food is digested for the first time, tiny protein fragments prompt certain
cells to produce specific IgE against that food. The IgE then attaches to the
surface of mast cells. The next time the particular food is eaten, the protein
interacts with the specific IgE on the mast cells and triggers the release of
chemicals such as histamine that produce the symptoms of an allergic reaction. If
the mast cells release chemicals in the nose and throat, the allergic person may
experience an itching tongue or mouth and may have trouble breathing or swallowing.
If mast cells in the gastrointestinal tract are involved, the person may have
diarrhea or abdominal pain. Skin mast cells can produce hives or intense itching. The
food protein fragments responsible for an allergic reaction are not broken down
by cooking or by stomach acids or enzymes that digest food. These proteins can
cross the gastrointestinal lining, travel through the bloodstream and cause allergic
reactions throughout the body. The
timing and location of an allergic reaction to food is affected by digestion.
For example, an allergic person may first experience a severe itching of the tongue
or "tingling lips." Vomiting, cramps or diarrhea may follow. Later,
as allergens enter the bloodstream and travel throughout the body, they can cause
a drop in blood pressure, hives or eczema, or asthma when they reach the lungs.
The onset of these symptoms may vary from a few minutes to an hour or two after
the food is eaten. Most
Likely Suspects
Food
allergy patterns in adults differ somewhat from those in children. The most common
foods to cause allergies in adults are shrimp, lobster, crab, and other shellfish;
peanuts (one of the chief foods responsible for severe anaphylaxis); walnuts and
other tree nuts; fish; and eggs.
In
children, eggs, milk, peanuts, soy and wheat are the main culprits. Children typically
outgrow their allergies to milk, egg, soy and wheat, while allergies to peanuts,
tree nuts, fish and shrimp usually are not outgrown.
Adults
usually do not lose their allergies. A
Growing Problem"The
prevalence of food allergy is growing and probably will continue to grow along
with all allergic diseases," says Robert A. Wood, M.D., director of the pediatric
allergy clinic at Johns Hopkins Medical Institutions in Baltimore. Wood
says that research over the last three decades indicates that the number of people
with allergies is skyrocketing in developed and developing countries, but not
in underdeveloped areas. "The
fewer germs in terms of infection and the environment, the more time the immune
system has to worry about things like allergens," says Wood. "Recent
studies indicate that growing up in a large family or daycare center actually
decreases the likelihood of developing an allergy." Wood,
who has had a severe peanut allergy since he was a toddler, says allergic reactions
to foods can vary dramatically. "They can range from just a mild rash to
very severe swelling in the throat and the airways in the lungs so that there
is a complete inability to breathe," he says. Wood's
parents learned of their son's allergy when they introduced him to peanut butter.
"The first time I had peanut butter I developed a rash and severe swelling
in my face," he says. "I'm extremely allergic. Just being around when
a peanut shell is broken and dust is being released is enough to cause a reaction. "I've
had a number of very dangerous reactions," Wood says. "People with a
food allergy typically walk around with a little bit of fear all the time. Once
it starts, it's a fear-generating experience." Multiple
AllergiesWhen
Sarah Buster of Columbia, Md., was 4 months old, her parents discovered that an
allergy to milk was causing her eczema, a chronic skin inflammation. Her skin
improved with a switch to a soy-based formula. Sarah's doctor believed there was
little cause for concern since many infants have eczema and most outgrow it by
age 2. Sarah didn't. Tests later indicated that she was allergic to eggs, peanuts,
tree nuts, penicillin, tree pollen, ragweed, dust mites, and dogs and cats. It
was then that Sarah's parents, Mike and Brenda Buster, began reading food labels
as carefully as they would a legal contract. They joined a food allergy advocacy
group, replaced the carpet in Sarah's bedroom and throughout the house with hardwood
floors, placed dust mite covers over her bedding, gave away the family's dogs,
and kept Sarah indoors as much as possible. A
small wooden chair with a wicker seat has taken the place of upholstered furniture
for 9-year-old Sarah, and devices that filter dust, pollen and other particles
hum both upstairs and downstairs. For
a time, soaking baths and ointment head-to-toe helped keep her skin moist, and
a prescription antihistamine eased the itching enough so she could sleep. However,
Sarah's eczema soon worsened again. "Sarah's
itching would be so severe that we could stand right by her and call her name
and she would not respond because she was so focused on scratching," says
Brenda Buster. "She would scratch until she bled because the pain felt better
than the itch." Finally,
allergists at Johns Hopkins eliminated all conventional food and put her on a
special formula made of amino acids. Sarah also started a four-month regime of
prednisone, a drug that mimics the effects of the body's natural corticosteroid
hormones and suppresses the activity of the immune system. Eventually,
her diet was expanded to six foods that doctors believed she was not allergic
to: turkey, pork, rice, apples, grapes and tomatoes, supplemented by the special
formula. Sarah's
skin cleared and after several months she began a series of dietary "challenges"--tests
to determine whether specific foods cause an allergic reaction. Several years
later, Sarah eats a more varied diet, and the Busters maintain a list of safe
foods and those that cause an allergic reaction. "The
most difficult thing I have faced with my allergies is that when I see my friends
eating something that I know I can't have, it just makes me feel left out,"
says Sarah. "We
never order food for Sarah at a restaurant because, even if the ingredients in
the food itself are safe, there is a considerable chance for cross-contamination
with something that's unsafe for her to eat," says Mike Buster. "For
example, a baked potato might be safe, but if the person preparing the potato
even touched a dairy, nut or egg product and then touched the potato, Sarah could
have a serious reaction. "We
go out to eat, but we bring all her food with us," he says. "It's just
not worth taking the chance." Wood,
who cares for Sarah at Johns Hopkins, says, "She's got it a lot tougher than
someone who just has a peanut allergy. She's dealing with this stuff on an every-single-meal
basis. Her parents have really helped provide her with a wonderful life."
That
life includes her favorite activities--ice-skating (she likes the cool air of
the rink) and swimming (the moisture and chlorine are beneficial to her skin,
according to her doctors). Sarah
continues to outgrow some of her allergies, and has added about a dozen foods
into her diet over the past year, Wood says. "The
taste in my mouth when I'm trying something new is very different," says
Sarah. "Strawberries felt hard because of the seeds. They tasted great but
I didn't like the texture, so my dad tried to take the seeds out. I still didn't
like the strawberries that much, but I kept reminding myself over and over again
that if I passed the test, I would be able to have a lot of things with strawberries
in it. Like now I can have strawberry Skittles." The
food at Sarah's Montessori school is nut-free, and on special school occasions,
Brenda Buster tries to prepare something that Sarah and her classmates can enjoy,
such as some types of candy, homemade cupcakes made without eggs or dairy products,
a nondairy frozen dessert, or popcorn prepared at home. "We
make our own bread and most other foods," says Brenda. "Although we
do have several more products we can buy, including one brand of potato chips
and one brand of pretzels, saltines and several types of canned vegetables." Still,
the Busters must be vigilant and can be found constantly checking labels. For
example, a type of food may be safe from one manufacturer but not from another.
"One brand of candy corn may be OK, while another contains eggs," says
Brenda. Even
foods that have proved to be safe previously can subsequently cause a problem.
"Manufacturers can change the ingredients without changing the packaging,"
adds Mike Buster. "We appreciate manufacturers who clearly label their products." Food
Labeling: A Critical ComponentCurrently,
the only way to treat food allergies is to avoid the foods that trigger reactions.
Even the most diligent label-readers and ingredient-checkers likely will be inadvertently
exposed to proteins that elicit an allergic response at some point. That's why
Wood, Sarah and others with food allergies severe enough to cause anaphylactic
reactions should wear medical alert bracelets or necklaces and carry a syringe
of adrenaline (epinephrine) obtained by prescription from their physicians. Anaphylactic
allergic reactions can be fatal even when they begin with mild symptoms such as
a tingling in the mouth and throat or gastrointestinal discomfort. Antihistamines
and bronchodilators can be used to treat less severe symptoms. FDA's
RoleSince
2000, the FDA has presented information on allergen risk and labeling requirements
at more than a dozen locations nationwide, says Kenneth J. Falci, Ph.D., who leads
the FDA's initiatives on food allergies. The
meetings provide the FDA with firsthand accounts from people with food allergies
and data that can be used to improve consumer labeling. The
FDA's food allergy efforts include focusing on the eight most common food allergens:
milk, eggs, fish, wheat, tree nuts, peanuts, soybeans and crustaceans (such as
shrimp and crabs). Proteins in these eight major foods are estimated to cause
90 percent of the allergic reactions in the United States. Industry
ResponseFood
manufacturers and consumer groups are working with the FDA to increase public
awareness of the seriousness of food allergen reactions and to ensure that allergens
are appropriately labeled in food products. An
allergen labeling program and a "code of practice" developed by the
National Food Processors Association that calls for listing the eight most common
food allergens in "plain language" are among the voluntary efforts being
undertaken. An
example of "plain language" is using the word "milk" in a
product's ingredient list as well as the less familiar "caseinate" or
using "eggs" in addition to "albumin." Falci
says FDA investigators nationwide are being trained how to properly inspect food-processing
plants for allergen control procedures. In addition, FDA officials have updated
a 1996 notice to the food industry addressing the problem of undeclared allergens
in food by recently publishing a
compliance policy guide. Falci
regularly speaks to food industry gatherings across the country to discuss many
allergen topics, including methods being used by some processors to avoid problems
related to food allergies. "Sharing
'best practices' in the industry through workshops is a really good way to get
people to talk to each other," Falci says. "This is not a competitive
edge issue. This is a safety concept, and sharing these thoughts is helpful to
everyone in the industry. "Altering
production scheduling is a practice that can have a huge impact on minimizing
the inadvertent introduction of undeclared allergens," says Falci. "Manufacturers
who use shared equipment to process foods without allergens can benefit from following
a carefully laid out production plan, such as running non-allergen-containing
products first, followed by those containing allergens, then a clean-up step." The
payoff? The shared equipment is less likely to contaminate other products with
undeclared allergens. In
August, the FDA will sponsor a workshop with the food industry, consumers, trade
associations and consumer advocate groups to discuss ways to improve the identification
of food allergens within the ingredients list. Falci
says that labeling food allergens in plain language--a source statement simple
enough for a child to know if an ingredient is derived from soy or milk, for example--and
precautionary food labeling are among the subjects likely to be discussed. Labeling
PolicyThe
Federal Food, Drug, and Cosmetic Act requires, in virtually all cases, that all
the ingredients of a food be listed on the food label. Two exemptions to the labeling
requirements recently have been involved in a number of reported food allergen
reactions: the collective naming of spices, flavorings, and colorings; and insignificant
levels of additives in a food that do not have a technical or functional effect
on the final product. The FDA, however, does not consider food allergens eligible
for the latter labeling exemption. The agency also strongly encourages the declaration
of an allergenic ingredient in a spice, flavor, or color. "While
the FDA believes that food processors make a sincere effort to label the ingredients
in their food products completely, it's clear from data on food recalls that firms
do miss including some allergenic ingredients on their food labels," says
Falci. Gaps
in Allergen Labeling Between
September 1999 and March 2000, FDA researchers working with state inspectors from
Wisconsin and Minnesota inspected 85 bakery product, ice cream and candy manufacturers
for allergen labeling and cross-contamination issues, with a focus on peanut and
egg allergens. Many of the firms in the study were small- to medium-sized operations.
The joint study was prompted, in part, by a jump in the number of national recalls
due to allergy-related ingredients not being listed on labels. Samples
were collected for egg and peanut protein analysis only when labeling or cross-contamination
issues were identified by the investigator. Eighteen of the 73 samples (25 percent)
of the ice cream, bakery and candy food product samples tested positive for peanut
allergens, although peanuts were not listed on product labels. Investigators also
found that companies unintentionally introduced food allergens into other foods
through poor cleaning and cooking schedules or improper cleaning of utensils.
"These
findings show that more work is needed," Falci says. The
inspectors also found that just over half of the manufacturers checked their products
to ensure that the labels accurately reflected all of the ingredients. "We
certainly have legal authority at the moment to allow for recalls of undeclared
allergens, and recalls are occurring for that reason," Falci says. "We're
only in the beginning stages of negotiating and talking with the food industry
about some things we'd like to potentially see on the label. However, the industry
is beginning to take voluntary actions, which we applaud."
Consumer InvolvementThe
Food Allergy & Anaphylaxis Network (FAAN), based in Fairfax, Va., has been
an advocate for simple, clear and accurate food labels for a decade. "Reading
food labels is the only way that food-allergic consumers can avoid dangerous allergens
in packaged food," says Anne Muñoz-Furlong, FAAN founder and president.
"If food manufacturers don't follow good manufacturing practices and carefully
control that what is in the package matches what is on the label, we are all in
big trouble." According
to Muñoz-Furlong, many large food companies have long been aware of how
serious food allergies can be, and have made appropriate changes in their manufacturing
and labeling practices. There are still many more companies that have yet to take
the issue seriously. For
example, Muñoz-Furlong says that today there are more than a dozen ways
to indicate the presence of milk protein without using the word "milk."
Another common problem is the term "nondairy." Many consumers mistakenly
believe that nondairy means there is no milk in a product. Current labeling guidelines
allow the use of "nondairy" when the foods contain milk byproducts. In
addition, manufacturers may use the term "natural flavors" even when
the product contains major allergens. To avoid a major allergen, a food-allergic
consumer would need to call the manufacturer before purchasing the product to
confirm that an allergen was present. A
review of food labels indicates an overuse of "may contain" statements,
leaving food-allergic people to wonder whether food companies are really looking
after their best interest, Muñoz-Furlong says. (See "FDAc/departs/2001/401_word.html">Living
With Food Allergies: Not As Easy As You Might Think.") Ray
Formanket Jr. is editor of FDA Consumer.
Common
Symptoms of an Allergic Reaction to Food -
Symptoms typically appear within minutes to two hours after a person has eaten
the food to which he or she is allergic.
- Tingling
sensation in the mouth
-
Swelling of the tongue and throat
-
Difficulty breathing
-
Hives
-
Vomiting
-
Abdominal cramps
-
Diarrhea
-
Drop in blood pressure
-
Loss of consciousness, and death.
For
More Information FDA
Center for Food Safety
and Applied Nutrition
Information About Food Allergies
www.cfsan.FDA.gov/~dms/wh-alrgy.html National
Institute of Allergy and Infectious Diseases
www.niaid.nih.gov The
Food Allergy & Anaphylaxis Network
www.foodallergy.org Publication
No. (FDA) 02-2332 Reprinted
from FDA Consumer. This article originally appeared in the July-August 2001 FDA
Consumer. We
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