Food
allergies and food intolerances are different but they are often confused.
About 2 of a 100 people have a food allergy but many more have food
intolerances.
Food allergy or
intolerance?
Food
intolerance is an adverse reaction to a particular food or ingredient, which
occurs every time the food is eaten. It's often confused with a food allergy,
but it's very different because the immune system isn't activated. A food
allergy is an allergic reaction to the food.
An allergy produces specific symptoms, such as swelling of the lips, which
usually develops within minutes of eating the food, while intolerance produces
more general symptoms, such as indigestion and bloating, which can develop
several hours after eating.
Only a tiny particle of food is needed to trigger a food allergy, whereas
you would usually need to eat a larger amount of food to trigger intolerance.
The symptoms of a food allergy can be life threatening, whereas the
symptoms of a food intolerance are unpleasant but are never immediately life
threatening
Food
intolerance occur when the body is unable to deal with a certain foodstuff,
usually because it doesn't produce enough of the chemical or enzyme needed to
properly digest that particular food.
One
of the most common intolerances is to cow's milk, which contains a certain type
of sugar called lactose. If you have a shortage of the enzyme lactase, you
can't break down milk sugar into simpler forms that can be absorbed into the
bloodstream. When intolerant to lactose the sufferer may experience symptoms
such as bloating, abdominal pain and diarrhoea when they eat or drink dairy
products,
Food allergies
Since
1990, there has been a 500 per cent increase in hospital admissions for food
allergies among the young. The most frequent food allergies in children are to
milk, eggs, soya, wheat, fish, nuts, citrus fruit and tomatoes. Food allergies
are more common in children than adults. According to a study done by the Food
Safety Agency in the UK
in 2008, it was estimated that 5 to 8% of children and 1 to 2% of adults
suffered from a food allergy.
In
general terms, there are two types of food allergy; an immediate type of
allergy and a delayed type of allergy. With immediate type allergies, you
notice a reaction very quickly after you eat the offending food, usually within
a few minutes. Symptoms include hives, itchiness and swelling and in extreme
cases, a potentially life-threatening allergic reaction called anaphylaxis.
Anaphylaxis is an extremely rare but potentially life threatening allergic
reaction which if left untreated may lead to death. Symptoms vary but can
include anxiety, shortness of breathe, palpitations, swelling of lips, tongue
or throat and loss of consciousness. An adrenaline injection is normally the
treatment of choice. The adrenaline device used in children is called an Anapen®
Junior device and must be prescribed by the child’s GP. It will only be
prescribed in cases of children known to suffer from anaphylactic attacks. It
should be carried everywhere by the child. The child’s parent must be trained
to recognise the symptoms of anaphylaxis and shown how to use the Anapen®
Junior device. The GP, practice nurse or pharmacist can demonstrate how to use
the device.
Delayed-type
allergies are more subtle and more difficult to detect. This is because it is
the chronic build-up of a particular food that causes the allergic reaction. In
young children, the most common delayed type of food allergy is to milk
protein, which causes chronic symptoms such as eczema, colic, reflux and diarrhoea. This should not to be confused with lactose intolerance, which does not involve the immune system. Delayed-type
allergies are difficult for doctors to diagnose because there's no obvious
relationship between eating the food and the onset of symptoms. Because of the
fact that these symptoms are also common in children without allergies makes a
diagnosis even more difficult.
Most children outgrow food allergies such as milk, eggs,
soya and wheat by the time that they start school. Peanut allergies are usually
more persistent in children. An estimated 80% of children with peanut
allergies remain allergic to peanuts for the rest of their life.
There is currently no cure for food
allergies. Treatment involves identifying the specific food that triggers
the allergic reaction and then avoiding it. If the child inadvertently eats the
food that causes the allergy, an antihistamine such as Zirtek® liquid can be given to the child to reduce symptoms such an itch and
hives. Zirtek® liquid is available in pharmacies
without prescription and is non drowsy so won’t affect school work.
Food intolerance
Food intolerance is more common
than food allergies. It can occur in adults and children. It occurs when the
body is unable to deal with a certain food. This is generally because the
affected person lacks enough of the particular chemical or enzyme that is
needed for digestion of that food.
One of the most common types is
intolerance of cow's milk, which contains a type of sugar called lactose. Many
people have a shortage of the enzyme lactase, which is normally made by cells
lining the small intestine. Without this enzyme, the lactose intolerant person
can not break down milk sugar into simpler forms that can be absorbed into the
bloodstream. Symptoms of lactose intolerance include indigestion, bloating,
flatulence, diarrhoea and nausea. Babies are usually born with higher levels of
lactase, so lactose intolerance usually only begins after the age of about two,
as the body begins to produce less of the enzyme. But many people don't
experience symptoms until they're much older. A temporary lactase deficiency
may follow gastroenteritis, especially in children. Lactose intolerance in
children and adults is sometimes misdiagnosed as irritable bowel syndrome (IBS)
as many of the symptoms are similar.
Lactose intolerance is less common
among people of northern and western European origin than people of Mediterranean, African, Native American and Asian origin.
The reason lactose intolerance is less common in northern and western Europe is
evolutionary as dairy consumption has long been a part of the diet in these
areas so lactase production has developed as part of evolution over time in
people from these areas. About 10 to 15% of the population in northern/western Europe suffer from lactose intolerance. In non-dairy
consuming societies such a Thailand,
lactose intolerance can be as high as 98% of the population as dairy is not a
major part of diet so lactase is not required.
Colic is the name given to the sharp,
intermittent abdominal pains suffered by 20-25% of babies. The exact cause of
colic is not fully understood, but a recent study in Guy’s Hospital in London found that over
half of babies suffering from colic had lactose intolerance. When the enzyme
lactase was added to the milk of the babies in the study, the symptoms either
disappeared or were significantly reduced. Lactase Enzyme drops are available
in Whelehan’s Pharmacy. Ask our pharmacist for advice and information and
treatment options if you feel your baby or child may be lactose intolerant.
Some people have adverse reactions
to chemical preservatives and additives in food and drinks, such as sulphites,
benzoates, salicylates, monosodium glutamate, caffeine, aspartame and
tartrazine. These can be hard to diagnose by eliminating foods so a food
intolerance test with a health professional may help.
The lack of a specific enzyme in
the body may lead to the build up of toxic by-products and histamine, which
then mimic the symptoms of an allergy. The symptoms of food intolerance can be
similar to an allergic reaction. This is why many tests for food intolerance,
including the one performed by Whelehan’s Pharmacy, check for IgG antibodies
which if present can detect certain food intolerance.
I will discuss more about Food
Intolerance in my next Health Blog
Food
intolerance test
Whelehans Food Intolerance Testing
Service checks for food intolerance to 59 of the most common causes of food
intolerance. If a patient tests positive, to certain foods, the simple act of
eliminating the food could have a massive positive impact on overall wellbeing.
Our food intolerance test costs €100; it only takes a few minutes and you can
have results later that day. We will advise on the best next steps depending on
your results. Call us at 04493 34591 to find out more or to book an
appointment.
Disclaimer: Food intolerance tests are
not meant as a substitute for full medical check-up from your GP
For comprehensive and free health advice and information
call in to Whelehans, dial 04493 34591 or log on to www.whelehans.ie.
You can also e-mail queries to info@whelehans.ie. Find us on
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