Transcript Food allergies - Food a fact of life

Unpleasant reactions to
food
© Food – a fact of life 2009
Extension
Learning objectives
• To understand there are many different reasons for
unpleasant reactions to food.
• To know which foods may cause a food intolerance
and/or allergy.
• To recognise the symptoms of food intolerance and
/or allergy.
• To understand the severity of peanut allergies.
• To recognise the seriousness of anaphylaxis.
• To understand the terms oral allergy syndrome and
exercise induced food allergy.
• To define the term food aversion.
• To understand the cause and effects of lactose
intolerance and coeliac disease.
© Food – a fact of life 2009
Food intolerance
Most people can eat foods
without any problems
although they may have
different likes or dislikes that
influence what they choose.
However, some people react
to certain foods and eating
them may cause
uncomfortable symptoms or,
in rare cases, a severe illness.
© Food – a fact of life 2009
Assistance with a food intolerance
It is important that people who think they suffer from a
food intolerance do not change their diet dramatically
so that it becomes unbalanced.
They should take advice from a dietitian or doctor to
make sure that the medical condition is properly
diagnosed. Care needs to be taken to ensure that
their diet contains a wide variety of foods to provide all
the nutrients they need, particularly the nutrient/s
normally provided by the foods they cannot eat.
It is important to consume a balanced diet for good
health.
© Food – a fact of life 2009
The eatwell plate
The eatwell plate is the UK guide to help people
achieve a balanced diet for good health.
© Food – a fact of life 2009
Reasons for food intolerance
There are many different reasons for unpleasant
reactions to food and these are generally referred to
as food intolerances.
Most unpleasant reactions to food are not true food
allergies.
A food allergy is one particular type of food
intolerance. This is a reaction that involve the body’s
immune system. Food intolerances may cause
uncomfortable symptoms, but only true allergies
involve the immune system.
© Food – a fact of life 2009
Food allergies
A true allergy is a reaction by the immune system. The
immune system is the body’s defence system, it
protects against foreign particles like bacteria and
viruses. Sometimes it may react to substances in foods,
or in the environment.
This is an allergic reaction. Some people are allergic to
particular components of food, for example the
proteins in wheat or egg.
The symptoms of an allergic response may be very
similar to those of a food intolerance.
© Food – a fact of life 2009
Causes of allergic reactions
Any food may cause an allergy, however, the most
common allergic reactions to food are from the
following:
• celery;
• cereals containing
gluten (wheat, rye
barley and oats;
• fish, molluscs, and
crustaceans (including
prawns and crabs);
• lupins (seeds similar to
legumes);
• milk and milk products.
© Food – a fact of life 2009
• mustard;
• nuts (including Brazil
nuts, hazelnuts, almonds,
and walnuts);
• peanuts
• sesame seeds;
• soya;
•sulphur dioxide or
sulphites.
Children and food allergy
The most common food allergy reactions in childhood
are:
• eggs;
• milk and milk products;
• nuts (including peanuts);
• soya;
• wheat.
It is common for most children to grow out of food
allergies early in their childhood.
© Food – a fact of life 2009
Symptoms of food allergies
A food allergy usually occurs between a few minutes
and a few hours after eating a particular food.
The symptoms of food allergies may be:
• coughing;
• dry, itchy throat and tongue;
• nausea and feeling bloated;
• wheezing and shortness of breath;
• swelling of the lips and throat;
• runny or blocked nose;
• sore, red and itchy eyes.
© Food – a fact of life 2009
Peanut allergy
In extremely rare cases, a severe allergic reaction
called anaphylaxis can cause death.
An example of this is a serious
allergy to peanuts or other nuts.
Peanut allergy is becoming increasingly common,
especially in children. Currently, the UK government
recommends that, where there is a family history of
allergy, pregnant mothers should not eat peanuts, and
that peanuts are not given to infants.
© Food – a fact of life 2009
Anaphylaxis
A severe allergic reaction can sometimes lead to
anaphylaxis. When someone has an anaphylactic
reaction, they may have symptoms in different parts of
the body at the same time.
This can lead to death if it is not treated immediately.
Treatment is usually an injection of adrenaline
(epinephrine). Most people with severe allergies will
have this with them at all occasions.
© Food – a fact of life 2009
Anaphylaxis
The first symptoms can develop within minutes of eating
the food. Other symptoms can take hours to develop.
Anaphylaxis is most commonly caused by food
allergies, but can also be caused by other things, such
as insect bites, and drug allergies.
Peanuts, milk, eggs and fish are the most common
foods to cause anaphylaxis in the UK.
© Food – a fact of life 2009
Oral allergy syndrome
Foods such as fruit and vegetables can cause reactions
such as itching, or rashes in the lips and mouth.
This is called oral allergy syndrome and is a symptom of
a food allergy.
When foods such a fruit and vegetables are cooked it
often destroys the allergens that cause this kind of
reaction, e.g. people who react to raw mango might be
able to eat cooked mango.
© Food – a fact of life 2009
Exercise - induced food allergy
This is a rare condition where an allergic reaction
develops when a person undertakes physical activity
within a few hours of eating a certain food.
A person may normally have a mild allergic reaction to
a food, but can have a severe reaction if they eat it just
before they participate in physical activity.
Scientists do not fully understand why some people
react this way.
© Food – a fact of life 2009
Trends in intolerances and allergies
Food intolerance is more common in children than in
adults. Children often grow out of the problem.
The Food Standards Agency estimates that as many as
20% to 30% of people in the UK think they suffer from
some kind of food intolerance.
However, surveys have shown that only about 1- 2% of
adults in the UK have a food allergy that can be
detected by tests.
© Food – a fact of life 2009
Food aversion
Some people’s symptoms
only occur if they know that
they are eating a particular
food – they do not occur if
the food is disguised.
This is called food aversion.
It may be because they
believe the food will cause
symptoms, or because the
food has been associated
with illness in the past.
© Food – a fact of life 2009
Lactose intolerance
One type of food intolerance is caused by the lack of
an enzyme that is needed to digest a component of
food. The most common example of this is lactose
intolerance where sufferers are unable to digest
lactose, the sugar found in milk.
This is because they have low levels of the enzyme
lactase, which breaks down the lactose so that it can
be absorbed.
© Food – a fact of life 2009
Lactose intolerance
If lactase levels are low, undigested lactose passes into
the large intestine where it causes pain and diarrhoea.
Lactose intolerance is common in some ethnic groups,
particularly where adults do not traditionally drink milk.
People with lactose intolerance can usually drink small
amounts of milk, yoghurt and eat cheese without
problems.
© Food – a fact of life 2009
Coeliac disease
Coeliac disease is an unpleasant reaction to gluten, a
protein found in cereals such as wheat, rye and barley.
The gluten damages the small intestine so people with
coeliac disease cannot absorb nutrients from food
normally.
Sufferers have stomach pain and diarrhoea after eating
foods that contain gluten.
Coeliac disease is usually first noticed in childhood.
© Food – a fact of life 2009
Coeliac disease
The disease can affect growth or cause weight loss.
People with coeliac disease must avoid foods that
contain gluten throughout their life, for example, bread
cakes, and biscuits. Many foods have small amounts of
wheat or other cereals added, so people with coeliac
disease must check food labels carefully.
Rice, maize and soya products do not contain gluten
so are acceptable, and gluten-free versions of foods
such as bread and pasta are available.
Coeliac disease affects about 1 in 300 people in the
UK.
© Food – a fact of life 2009
Review of the learning objectives
• To understand there are many different reasons for
unpleasant reactions to food.
• To know which foods may cause a food intolerance
and/or allergy.
• To recognise the symptoms of food intolerance and
/or allergy.
• To understand the severity of peanut allergies.
• To recognise the seriousness of anaphylaxis.
• To understand the terms oral allergy syndrome and
exercise induced food allergy.
• To define the term food aversion.
• To understand the cause and effects of lactose
intolerance and coeliac disease.
© Food – a fact of life 2009
For more information visit
www.nutrition.org.uk
www.foodafactoflife.org.uk
© Food – a fact of life 2009