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Let your food be your medicine, and your medicine be your food. ...Hippocrates |
Controversial and Unproven Diagnostic Theories
Controversial and Unproven Disorders
There are several disorders that are popularly thought by
some to be caused by food allergies.
Either there is not enough scientific
evidence to support those claims,
or there is evidence that goes against
such claims.
Migraine headaches
There is controversy about whether
migraine headaches can be caused
by food allergy. Studies show people
who are prone to migraines can have
their headaches brought on by histamine and other
substances in foods. The more difficult issue is whether food
allergies actually cause migraines in such people.
Arthritis
There is virtually no evidence that most rheumatoid arthritis
or osteoarthritis can be made worse by foods, despite claims
to the contrary.
Allergic tension fatigue syndrome
There is no evidence that food allergies can cause a disorder
called the allergic tension fatigue syndrome, in which people
are tired, nervous, and may have problems concentrating or
have headaches.
Cerebral allergy
Cerebral allergy is a term that has been given to people
who have trouble concentrating and have headaches as well
as other complaints. These symptoms are sometimes blamed
on mast cells activated in the brain but no other place in
the body. Researchers have found no evidence that such a
scenario can happen. Most health experts do not recognize
cerebral allergy as a disorder.
Environmental illness
In a seemingly pristine environment, some people have many
nonspecific complaints such as problems concentrating or
depression. Sometimes this is blamed on small amounts of
allergens or toxins in the environment. There is no evidence
that these problems are due to food allergies.
Childhood hyperactivity
Some people believe hyperactivity in children is caused by
food allergies. Researchers, however, have found that this
behavioral disorder in children is only occasionally associated
with food additives, and then only when such additives are
consumed in large amounts.
There is no evidence that a true food allergy can affect a child’s
activity except for the possibility that if a child itches and
sneezes and wheezes a lot, the child may be uncomfortable
and therefore more difficult to guide. Also, children who are
on anti-allergy medicines that cause drowsiness may get
sleepy in school or at home.
Controversial and Unproven Diagnostic Methods
Cytotoxicity testing
One controversial diagnostic technique is cytotoxicity testing,
in which a food allergen is added to a blood sample. A
technician then examines the sample under the microscope to
see if white cells in the blood “die.” Scientists have evaluated
this technique in several studies and have found it does not
effectively diagnose food allergy.
Provocative challenge
Another controversial approach is called sublingual (placed
under the tongue) or subcutaneous (injected under the skin)
provocative challenge. In this procedure, diluted food allergen
is put under your tongue if you feel that your arthritis, for
instance, is due to foods. The technician then asks you if the
food allergen has made your arthritis symptoms worse. In
clinical studies, researchers have not shown that this procedure
can effectively diagnose food allergy.
Sublingual provocative challenge is not the same as a potentially new treatment for food allergy called sublingual immunotherapy or SLIT. Researchers are currently evaluating this treatment.
Immune complex assay
An immune complex assay is sometimes done on people
suspected of having food allergies to see if groups, or complexes,
of certain antibodies connect to the food allergen in the
bloodstream. Some think that these immune groups link with
food allergies. The formation of such immune complexes is
a normal offshoot of food digestion, however, and everyone,
if tested with a sensitive-enough measurement, has them.
To date, no one has conclusively shown that this test links
with allergies to foods.
IgG subclass assay
Another test is the IgG subclass assay, which looks specifically
for certain kinds of IgG antibody. Again, there is no evidence
that this diagnoses food allergy.