Food Allergies, Rare but Risky

                  A Reprint from FDA Consumer Magazine

Do you start itching whenever you eat peanuts?  Does seafood cause your
stomach to churn?  Symptoms like these cause millions of Americans to
suspect they have a food allergy.

But true food allergies affect a relatively small percentage of people.
Experts estimate that only 2 percent of adults, and from 2 to 8 percent
of children, are truly allergic to certain foods.  Food allergy is
different from food intolerance, and the term is sometimes used in a
vague, all-encompassing way, muddying the waters for people who want to
understand what a real food allergy is.

"Many people who have a complaint, an illness, or some discomfort
attribute it to something they have eaten.  Because in this country we
eat almost all the time, people tend to draw false associations (between
food and illness)," says Dean Metcalfe, M.D., head of the Mast Cell and
Physiology Section at the National Institute of Allergy and Infectious
Diseases.

Allergy and Intolerance-Different Problems

The difference between an allergy and an intolerance is how the body
handles the offending food.  In a true food allergy, the body's immune
system recognizes a reaction-provoking substance, or allergen, in the
food-usually a protein-as foreign and produces antibodies to halt the
"invasion."  As the battle rages, symptoms appear throughout the body.
The most common sites are the mouth (swelling of the lips), digestive
tract (stomach cramps, vomiting, diarrhea), skin (hives, rashes or
eczema), and the airways (wheezing or breathing problems). People with
allergies must avoid the offending foods altogether.

Cow's milk, eggs, wheat, and soy are the most common sources of food
allergies in children.  Allergists believe that infant allergies are the
result of immunologic immaturity and, to some extent, intestinal
immaturity.  Children sometimes outgrow the allergies they had as
infants, but an early peanut allergy may be lifelong.  Adults are
usually most affected by tree nuts, fish, shellfish, and peanuts.

Food intolerance is a much more common problem than allergy. Here, the
problem is not with the body's immune system, but, rather, with its
metabolism.  The body cannot adequately digest a portion of the
offending food, usually because of some chemical deficiency.  For
example, persons who have difficulty digesting milk (lactose
intolerance) often are deficient in the intestinal enzyme lactase, which
is needed to digest milk sugar (lactose). The deficiency can cause
cramps and diarrhea if milk is consumed. Estimates are that about 80
percent of African-Americans have lactose intolerance, as do many people
of Mediterranean or Hispanic origin.  It is quite different from the
true allergic reaction some have to the proteins in milk.  Unlike
allergies, intolerances generally intensify with age.

Dangerous Dishes

For people with true food allergies, the simple pleasure of eating can
turn into an uncomfortable-and sometimes even dangerous-situation. For
some, food allergies cause only hives or an upset stomach; for others,
one bite of the wrong food can lead to serious illness or even death.

Food intolerance may produce symptoms similar to food allergies, such as
abdominal cramping.  But while people with true food allergies must
avoid offending foods altogether, people with food intolerance can often
eat some of the offending food without suffering symptoms. The amount
that may be eaten before symptoms appear is usually very small and
varies with each individual.

Common Sites for Allergic Reactions

mouth (swelling of the lips or tongue, itching lips)

airways (wheezing or breathing problems)

digestive tract (stomach cramps, vomiting, diarrhea)

skin (hives, rashes or eczema)

[Graphic Omitted]

When Food Additives Are a Problem

Over the years, people have reported to FDA adverse reactions to certain
food additives, including aspartame (a sweetener), monosodium glutamate
(a flavor enhancer), sulfur- based preservatives, and tartrazine, also
known as FD&C Yellow No. 5 (a food color).  The federal Food, Drug, and
Cosmetic Act requires that FDA ensure the safety of all substances added
to foods, but individual health conditions sometimes cause problems with
certain additives.

*Aspartame

After reviewing scientific studies, FDA determined in 1981 that
aspartame was safe for use in foods.  In 1987, the General Accounting
Office investigated the process surrounding FDA's approval of aspartame
and confirmed the agency had acted properly.  However, FDA has continued
to review complaints alleging adverse reactions to products containing
aspartame.  To date, FDA has not determined any consistent pattern of
symptoms that can be attributed to the use of aspartame, nor is the
agency aware of any recent studies that clearly show safety problems.

Carefully controlled clinical studies show that aspartame is not an
allergen.  However, certain people with the genetic disease
phenylketonuria (PKU), those with advanced liver disease, and pregnant
women with hyperphenylalanine (high levels of phenylalanine in the
blood) have a problem with aspartame because they do not effectively
metabolize the amino acid phenylalanine, one of aspartame's components.
High levels of this amino acid in body fluids can cause brain damage.
Therefore, FDA has ruled that all products containing aspartame must
include a warning to phenylketonurics that the sweetener contains
phenylalanine.

*Monosodium glutamate

Monosodium glutamate (MSG) has been used for many years in home and
restaurant foods, and in processed foods.  People sensitive to MSG may
have mild and transitory reactions when they eat foods that contain
large amounts of MSG (such as would be found in heavily flavor-enhanced
foods).  Because MSG is commonly used in Chinese cuisine, these
reactions were initially referred to as "Chinese restaurant syndrome."

FDA believes that MSG is a safe food ingredient for the general
population.  It is regarded by the agency as among food ingredients that
are "generally recognized as safe."  FDA has studied adverse reaction
reports and other data concerning MSG's safety.  The agency also has an
ongoing contract with the Federation of American Societies for
Experimental Biology to reexamine the scientific data on possible
adverse reactions to glutamate in general.  MSG must be declared on the
label of any food to which it is added.

*Sulfites

Of all the food additives for which FDA has received adverse reaction
reports, the ones that most closely resemble true allergens are
sulfur-based preservatives.  Sulfites are used primarily as antioxidants
to prevent or reduce discoloration of light colored fruits and
vegetables, such as dried apples and potatoes, and to inhibit the growth
of microorganisms in fermented foods such as wine.

Though most people don't have a problem with sulfites, they are a hazard
of unpredictable severity to people, particularly asthmatics, who are
sensitive to these substances.  FDA uses the term "allergic-type
responses" to describe the range of symptoms suffered by these
individuals after eating sulfite-treated foods. Responses range from
mild to life-threatening.

FDA's sulfite specialists say scientists, at this time, are not sure how
the body reacts to sulfites.  To help sulfite- sensitive people avoid
problems, FDA requires the presence of sulfites in processed foods to be
declared on the label, and prohibits the use of sulfites on fresh
produce intended to be sold or served raw to consumers (see "A Fresh
Look at Food Preservatives" in the October 1993 FDA Consumer).

*FD&C Yellow No. 5

Color additives must go through the same safety approval process as food
additives.  But one color, FD&C Yellow No. 5 (listed as tartrazine on
medicine labels), may prompt itching or hives in a small number of
people.

Since 1980 (for drugs taken orally) and 1981 (for foods), FDA has
required all products containing Yellow No. 5 to list it on the labels
so sensitive consumers could avoid it.  (As of May 8, 1993, food labels
must list all certified colors as part of the requirements of the
Nutrition Labeling and Education Act of 1990.  See "From Shampoo to
Cereal, Seeing to the Safety of Color Additives" in the December 1993
FDA Consumer.)

True Allergies

Heredity may cause a predisposition to have allergies of any type, and
repeated exposure to allergens starts sensitizing those who are
susceptible.  Some experts believe that, rarely, a specific allergy can
be passed on from parent to child.  Several studies have indicated that
exclusive breast-feeding, especially with maternal avoidance of major
food allergens, may deter some food allergies in infants and young
children.  (Smoking during pregnancy can also result in the increased
possibility that the baby will have allergies.)  Most patients who have
true food allergies have other types of allergies, such as dust or
pollen, and children with both food allergies and asthma are at
increased risk for more severe reactions.

Life-Threatening Reactions

The greatest danger in food allergy comes from anaphylaxis, a violent
allergic reaction involving a number of parts of the body
simultaneously.  Like less serious allergic reactions, anaphylaxis
usually occurs after a person is exposed to an allergen to which he or
she was sensitized by previous exposure (that is, it does not usually
occur the first time a person eats a particular food).  Although any
food can trigger anaphylaxis (also known as anaphylactic shock),
peanuts, tree nuts, shellfish, milk, eggs, and fish are the most common
culprits.  As little as one-fifth to one-five-thousandth of a teaspoon
of the offending food has caused death.

Anaphylaxis can produce severe symptoms in as little as 5 to 15 minutes,
although life-threatening reactions may progress over hours. Signs of
such a reaction include: difficulty breathing, feeling of impending
doom, swelling of the mouth and throat, a drop in blood pressure, and
loss of consciousness.  The sooner that anaphylaxis is treated, the
greater the person's chance of surviving.  The person should be taken to
a hospital emergency room, even if symptoms seem to subside on their
own.

There is no specific test to predict the likelihood of anaphylaxis,
although allergy testing may help determine what a person may be
allergic to and provide some guidance as to the severity of the allergy.
Experts advise people who are susceptible to anaphylaxis to carry
medication, such as injectable epinephrine, with them at all times, and
to check the medicines's expiration date regularly. Doctors can instruct
patients with allergies on how to self-administer epinephrine. Such
prompt treatment can be crucial to survival.

Injectable epinephrine is a synthetic version of a naturally occurring
hormone also known as adrenaline.  For treatment of an anaphylactic
reaction, it is injected directly into a thigh muscle or vein.  It works
directly on the cardiovascular and respiratory systems, causing rapid
constriction of blood vessels, reversing throat swelling, relaxing lung
muscles to improve breathing, and stimulating the heartbeat.

Epinephrine designed for emergency home use comes in two forms: a
traditional needle and syringe kit known as Ana-Kit, or an automatic
injector system known as Epi-Pen.  Epi-Pen's automatic injector design,
originally developed for use by military personnel to deliver antidotes
for nerve gas, is described by some as "a fat pen."  The patient removes
the safety cap and pushes the automatic injector tip against the outer
thigh until the unit activates.  The patient holds the "pen" in place
for several seconds, then throws it away.

While Epi-Pen delivers one premeasured dosage, the Ana-Kit provides two
doses.  Which system a patient uses is a decision to be made by the
doctor and patient, taking into account the doctor's assessment of the
patient's individual needs.

Advice from Study

Hugh A. Sampson, M.D., and colleagues at Johns Hopkins University School
of Medicine in Baltimore, Md., published a study of anaphylactic
reactions in children in the Aug. 6, 1992, issue of The New England
Journal of Medicine.  The study involved 13 children who had severe
allergic reactions to food: Six died, and seven nearly died.  Among the
study's conclusions: * Asthma, a disease with allergic underpinnings,
was common to all children in the study. * Epinephrine should be
prescribed and kept available for those with severe food allergies. *
Children who have an allergic reaction should be observed for three to
four hours after a reaction in a medical center capable of dealing with
anaphylaxis.

Anne Munoz-Furlong, who founded The Food Allergy Network for people with
food allergies in 1991 after struggling to deal with her own child's
allergies, comments: "My youngest daughter was diagnosed with milk and
egg allergies when she was 9 months old, nine years ago. We tried to
lead a life around her restricted diet.  For example, we had Jell-O mold
for her first birthday because I didn't know it was possible to create a
cake without milk or eggs.  I knew there must be other families
struggling with the same issues."

Finding the Forbidden

Because there is no "cure" for food allergies other than strict
avoidance of an offending food, one of the biggest problems those with
food allergies face is verifying whether a forbidden product is
contained in a particular food.  For example, in Sampson's study, all
six deaths occurred because either the child or the parent was unaware
the food contained a substance to which the child was allergic.
Munoz-Furlong says the Nutrition Labeling and Education Act, which
requires more complete food labeling, should greatly help people with
food allergies to avoid dangerous foods.

The new labeling changes will make it easier for the consumer to readily
identify things they could be allergic to," says Linda Tollefson,
D.V.M., chief of the epidemiology branch at FDA's Center for Food Safety
and Applied Nutrition.  "Before this law was passed, true allergens were
required to be on the label, but the exceptions were standardized foods,
which will now have to list all ingredients."

According to Elizabeth J. Campbell, director of the center's division of
programs and enforcement policy, the principle underlying standardized
foods originally was that people basically knew what was in various
foods.

"Originally food standards were adopted to ensure uniformity.  If you
saw a product labeled mayonnaise, food standardization meant it had to
be mayonnaise.  People used to know what was in mayonnaise; nowadays
they have to be told that mayonnaise contains both eggs and oil,"
Campbell says.  "Years ago, when the law was first written to provide
for standards of identify for certain foods, it only required that
optional ingredients be declared.  The new law stipulates that all
ingredients in standardized foods must be declared." (See "Ingredient
Labeling: What's in a Food?" in the April 1993 FDA Consumer.)

Campbell believes that once the labeling is in place, consumers will
have the information they need to make correct food choices.  "In most
cases, ingredients have to be labeled simply because they are
ingredients, not because they are unsafe," she stresses.  "For those
with food allergies, I think it is more of a patient education problem."

Food additives, such as sulfites and certain colors, can also cause
problems for people sensitive to them.  (See "A Fresh Look at Food
Preservatives" in the October 1993 FDA Consumer and "From Shampoo to
Cereal: Seeing to the Safety of Color Additives" in the December 1993
FDA Consumer.)

"If you have a food allergy, you really have to alter your life,"
Tollefson says.  "You have to really read labels, and really be careful
about what you eat."

Steve Taylor, Ph.D., a professor and head of the Department of Food
Science and Technology at the University of Nebraska in Lincoln, says
the biggest problem for people with food allergies is restaurant food.
Historically, restaurants have been regulated by local health
departments and have not had to label foods.

"For many restaurants, labeling of food products they serve would cause
horrendous problems...what about chalkboard menus? How would you include
all the ingredients?  Enforcement would be a nightmare," he admits.

But steps are being taken to better educate restaurant employees. The
Food Allergy Network and The American Academy of Allergy and Immunology,
along with The National Restaurant Association, recently produced a
pamphlet on food allergies which has been distributed to 30,000 members
of the association.  The brochure explains what restaurants can do to
help customers who need to avoid certain foods, defines anaphylaxis, and
advises employees on what to do if food allergy incidents occur.

John A. Anderson, M.D., director of the Allergy and Immunology Training
Program at Henry Ford Hospital in Detroit, says changes in food habits
may be responsible for the feeling some physicians have that food
allergies may be on the rise.

"You could make a case for the fact that we are introducing peanuts, in
the form of peanut butter, to people at a very young age, which would
affect the prevalence rate for people who are sensitive to that
allergen," he notes.  "In Japan, where they use more soy, there is a
higher prevalence of soy allergy.  My feeling is that as soy, a cheap
protein supplement, is put in a lot of commercial foods you will see an
increase in the rate of sensitivity worldwide."

Metcalfe says that if food allergies are rising, it is due to more
common use of foods that tend to be allergenic.  He cites milk as a
source of protein supplement in many prepared foods, and points out that
people are eating more exotic seafood and more fish.

"But it's important to remember that the majority of people with true
food allergies are allergic to three or fewer foods," Metcalfe says.

Other than advising anyone with a known or suspected severe food allergy
to carry and know how to self-administer epinephrine, there is no
treatment for food allergy other than to eliminate the offending food.
But Metcalfe is optimistic about the future.

"I don't think it is likely a drug will be found to prevent food
allergies.  But I do think within 10 years we will see allergy shots
available for some of the more common food allergies, because we are
learning to identify and purify food allergens.  I think we will see
some development of immunotherapy for food allergies," he says.

Experts estimate that only 2 percent of adults, and from 2 to 8 percent
of children, are truly allergic to certain foods.

Food Allergies and Biotechnology

People with food allergies have expressed the concern that new varieties
of food, developed through the new techniques of biotechnology (such as
gene splicing), may introduce allergens not found in the food before it
was altered.

FDA addressed this concern in its 1992 biotechnology policy statement
and said it will regulate whole foods developed through biotechnology by
applying the same rigorous safety standards as for all other foods.  The
agency is taking steps to ensure that foods developed through
biotechnology do not pose any new risks for consumers.

Under the new policy guidelines, a protein copied by genetic engineering
from a food commonly known to cause an allergic reaction is presumed to
be allergenic unless clearly proven otherwise.  Any food product of
biotechnology that contains such proteins must list the allergen on the
label.

Labeling would not be required if the manufacturer could demonstrate
that the allergen was not transferred.  For example, if a food company
were to breed potatoes containing a genetically engineered soy protein
(to which some people might be allergic), the labeling on the potatoes
would have to disclose the presence of the soy protein. But labeling
would not be required if scientific data clearly showed that the protein
had been changed and no longer contained the soy allergen.

To ensure that FDA has state-of-the-art information for its food
biotechnology policy, the agency will sponsor a scientific conference in
the spring of 1994 to discuss what makes a substance a food allergen.

How to Cope

What should you do if you suspect you have a food allergy?

The Food Allergy Network's Anne Munoz-Furlong suggests keeping a food
diary as a first step, writing down everything you eat or drink for a
one- or two-week period.  Note any symptoms and how long it took for
such symptoms to develop.

But Furlong and other experts agree that those who suspect food
allergies also need to be evaluated by a physician with intensive
specialty training in allergy and immunology.  Be sure to discuss what
diagnostic and treatment plan is anticipated and the costs.

Ask if the tests have been proven effective by accepted standards of
scientific evaluation.

"Go to a board-certified physician who is an allergy expert," advises
Paul C. Turkeltaub, M.D., associate director of the division of
allergenic products and parasitology at FDA's Center for Biologics
Evaluation and Research.  "Be very wary of claims of food allergy to
explain chronic, common complaints."

The diagnosis of food allergy requires a careful history, physical exam,
appropriate exclusion diet, and diagnostic tests to rule out other
conditions.  Tests can include direct allergy skin tests, blood tests,
or "elimination and challenge" tests for suspected foods.

The most accurate kind of test is a controlled challenge test, often
done in "blind" or "double-blind" fashion to eliminate psychological
factors.  In a blind challenge, the patient is given either a sample of
the food, without being told what it is, or a placebo, an inert
substance used as a control in the test.  The observer (a doctor or
assistant), however, knows what the substance is.  Both patient and
observer record any symptoms of allergic reaction.  In a double-blind
challenge, neither the patient nor the observer knows if the patient is
given the food (allergen) or the placebo.

In recent years, unproven tests such as "food cytotoxic blood tests" and
"sublingual provocation food testing" have been promoted as supposed
"diagnosic" tools to detect food allergies. FDA believes that food
cytotoxic blood tests are not supported by well-controlled studies and
clinical trials.

In food cytotoxic testing, a test tube of blood is taken from the
patient.  The white cells (leukocytes) are mixed with plasma and sterile
water and placed on microscope slides coated with dried extracts of a
particular food.  The reaction of the cells is then examined under a
microscope; if they change shape, disintegrate, or collapse-or the
person examining them says they do-the patient is supposedly allergic to
that particular food. Test results may be interpreted by a "nutritional
counselor" working on commission, who recommends vitamins and minerals
(often available on site) that the patient needs to correct his or her
"allergic condition."  But FDA and other experts emphasize there is no
evidence that such tests are valid in diagnosing food allergies.

Sublingual provocation food testing dates back to 1944.  The tests
consists of placing three drops  of an allergenic extract under a
patient's tongue and waiting 10 minutes for any symptoms to appear. When
the doctor is satisfied he has determined the cause of the symptoms, he
administers a "neutralizing" dose, which is usually three drops of a
diluted solution of the same allergenic extract.  The symptoms are then
expected to disappear in the same sequence in which they appeared.
Advocates claim that if the neutralizing dose is given before a
challenge test (for instance, eating a meal containing the offending
food), the person will not have symptoms.

But after careful study of existing data, The American Academy of
Allergy and Immunology says no controlled clinical studies demonstrate
either diagnostic or therapeutic effects of sublingual provocation food
testing.  The academy concludes that use of the tests should be reserved
for experiments in well- designed trials.

If you are diagnosed with a food allergy, scrutinize food labels to
detect potential sources of food allergens.  When eating out, ask about
ingredients if you are unsure about a particular food; ask to talk to
the manager of the restaurant about ingredients in specific dishes.

Keep epinephrine with you and know how to administer it.  If you do
experience a reaction, seek medical attention immediately, even if the
symptoms are mild or seem to subside.  Mild symptoms may be followed 10
to 60 minutes later by the onset of severe problems.

More Information

For more information about food allergies, contact the following groups:

The Food Allergy Network
4744 Holly Ave.
Fairfax, VA  22030-5647
(703) 691-3179

American Academy of Allergy and
Immunology
611 East Wells St.
Milwaukee, WI  53202
(414) 272-6071

Physician Referral Hotline
(1-800) 822-ASMA

The American Dietetic Association
216 W. Jackson Blvd.
Chicago, IL 60606-6995
(1-800) 877-1600

For a free copy of An FDA Consumer Special Report: Focus on Food
Labeling, which includes the article on ingredient labeling, write to
FDA, HFE-88, 5600 Fishers Lane, Rockville, MD 20857.

A REPRINT FROM FDA CONSUMER MAGAZINE

Printed May 1994.
This reprint contains revisions made in May 1994.  This article
originally appeared in the December 1993 FDA Consumer.
PUBLICATION NO. (FDA) 94-2279

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