When Food is Not a Friend

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When Food is Not a Friend - a basic guide to food allergy and intolerance

 

http://www.sanitarium.com.au/article/article.do?art-id=249

 

Food allergy & food intolerance - what's the difference?

 

Imagine living with the reality that even the most healthy food could be a

problem for you, could make you feel unwell, could give you an uncomfortable

rash or in severe cases, could be life threatening. It seems that many

people these days claim to have a 'food allergy'. However a true food

allergy is not as common as you may think. In fact the adverse reactions to

food that are commonly thought to be an allergic reaction are quite often

due to a food intolerance rather than an allergy. In this feature article,

we will look at the difference between food allergy and food intolerance,

the symptoms, common trigger foods, treatment options and where to go for

more information. You will also find recipes in this issue, to meet the

needs of people who have allergies or intolerances to different foods.

 

Food allergy

 

A food allergy is when a person's immune system produces antibodies to a

particular food protein that it believes is harmful.

When an individual eats that food, their immune system releases chemicals,

including histamine, in order to protect the body.

Some of the most common allergic reactions include eczema, asthma and hay

fever and in severe cases, anaphylactic shock.

Foods that are commonly responsible for allergic reactions in people

include:

 

milk

eggs

peanut

tree nuts (walnuts, cashews etc.)

fish

wheat

shellfish

soy

 

Although research is being conducted into food allergies and new treatments,

at present, total avoidance of the problem food is the only way to prevent a

reaction.

 

A food allergy is usually first identified as a problem for infants,

toddlers and young children. While children are often allergic to 2-3

(sometimes even more) different foods, fortunately most tend to grow out of

some allergies, particularly egg and milk allergies, by school age.

 

However, allergies to nuts and seafood can often persist into adulthood.

Occasionally new food allergies can arise in adulthood however this usually

occurs with crustaceans and other more exotic foods that are not eaten

during childhood. However, most adverse reactions to food, which develop in

adulthood, are due to food chemical intolerances, rather than allergies[1].

 

Diagnosing a food allergy[2]:

 

Unfortunately, most of these methods are not supported by scientific

evidence and as such are considered unreliable. Some of these diagnostic

tests and treatments include Kinesiology, ALCAT blood testing, Iridology,

Hair analysis, Acupuncture and Reflexology.

 

For a firm diagnosis of a true food allergy, an immunologist needs to

conduct a skin prick test or a blood test (RAST or radioallergosorbent test)

to detect if someone has antibodies to the common food allergens.

 

WHAT IS ANAPHYLACTIC SHOCK?

 

An anaphylactic reaction is a severe, rapidly progressive allergic reaction

that can be life threatening unless treated immediately. Symptoms can begin

within minutes of exposure with hives and swelling of the mouth and throat

area, vomiting, diarrhoea, asthma, difficulty breathing and even loss of

consciousness. People with severe food allergies need to be very careful as

even a trace amount of the problem food can cause a reaction in some

individuals. People who are experiencing an anaphylactic reaction need an

immediate injection of adrenalin to help reverse the symptoms and prevent

the progression of the reaction.

 

Food Intolerance

 

Unlike food allergy, a food intolerance causes an adverse reaction to a food

but it does not involve the person's immune system. Rather, the symptoms of

food intolerance are triggered by food chemicals.

Many people may not be aware of intolerances to food chemicals. These may be

artificial chemicals (food additives) added to processed foods but they also

include chemicals found naturally in foods. The common natural food

chemicals that may cause problems in sensitive people include:

 

Salicylates found in many fruits & vegetables, tea, coffee, fruit juices,

beer, wine, soft drinks & cordials, honey, jam, peppermint, commercial

sauces and stocks.

 

Amines found in some vegetables and fruit (particularly bananas and

avocados), cured meats, cheese, chocolate, beer, wine, caffeine, fish

products, commercial sauces, stocks and yeast extracts.

Glutamates present in mushrooms, tomatoes, sultanas, cheese, commercial

stocks, soups and sauces, processed meats, yeast extracts.

 

The symptoms of food intolerance are varied and can often be very similar to

those of a milder food allergy which is why some people may report they have

a food allergy when really, it is far more likely to be a food intolerance,

or even another medical condition altogether. People with a food intolerance

may suffer from symptoms such as hives, skin swellings, eczema, bowel

irritation and stomach pains, headaches, fatigue, irritability, muscular

aches and pains, poor concentration. In children, behavioural problems

associated with disorders such as ADHD (attention deficit hyperactivity

disorder), can also be aggravated if the child is sensitive to some food

chemicals.

 

People may be born reacting to certain chemicals, or the intolerances can

develop in later life, usually triggered by environmental factors such as a

change in diet or illness.

 

Identifying food intolerance

 

Intolerances to food chemicals can only be identified by an elimination diet

and challenge procedure, usually best conducted under the supervision of an

Accredited Practising Dietitian (APD) as initially the diet is quite

restrictive (and bland in flavour as foods high in food chemicals tend to be

the most tasty!) The elimination diet involves following a low chemical diet

for 3 or 4 weeks and then 'challenging' with carefully selected foods,

one-by-one, to identify the chemicals that cause the symptoms.

 

Once identified, problem food chemicals, such as food additives and

artificial colours and flavours, can be avoided by checking food labels and

staying away from foods that contain these chemicals. However people who are

sensitive to natural food chemicals may find enjoying even the most healthy

whole foods a daily challenge.

 

Food intolerance reactions are dose dependant. This means that some people

may be able to tolerate small amounts of a chemical before they experience

an adverse reaction. People who are very sensitive have a far lower

threshold than others and may need to eat mainly low chemical foods, while

others will be able to enjoy a more varied diet just by being careful to not

overindulge in the chemical rich foods. There are also people who may be

able to build up their tolerance threshold over time by gradually increasing

the amount of low-moderate chemical foods they consume. For these fortunate

people, a relatively normal diet is achievable[1].

 

Lactose Intolerance

 

People with lactose intolerance have difficulty digesting lactose, which is

the type of sugar found naturally in milk and many dairy foods. Many people

with this condition can however tolerate small amounts of these foods,

especially yoghurt and matured cheese that are often quite low in lactose.

Again, the key to managing lactose intolerance is determining a tolerance

threshold to avoid the uncomfortable symptoms of bloating, wind, cramps and

diarrhoea, or finding equivalent lactose free alternatives, such as enriched

soymilks.

 

Coeliac disease[3]

 

People who have coeliac disease are sensitive to gluten which is a protein

found in common grains including wheat, barley and rye. Oats may also be a

minor source of gluten. The reaction causes inflammation and damage to the

lining of the small bowel, which impairs its ability to absorb nutrients.

 

Those affected may experience symptoms of fatigue, diarrhoea, cramping and

bloating, nausea and vomiting, weight loss and constipation. These can also

be symptoms of many other medical conditions including other food

sensitivities. So, it is important not to self diagnose coeliac disease or

'gluten intolerance' and unnecessarily start excluding bread, pasta,

breakfast cereals and other gluten containing foods from your diet. A firm

diagnosis relies on a small bowel biopsy, which requires the person to have

been including gluten in their diet up until the testing. Check with your

doctor before making your diet too restrictive!

 

Currently, the only known treatment for coeliac disease is total avoidance

of gluten. This is important as if untreated, the condition may lead to

nutritional deficiencies, osteoporosis and even gastrointestinal cancer.

 

For those who need to exclude gluten from their diet there are a number of

nourishing substitutes including rice, potato, buckwheat, millet, corn,

polenta, soybeans and other legumes. Many of these ingredients can be

purchased as flours suitable for baking. There are also an increasing number

of gluten free commercial products including breads, biscuits, pasta and

flours available in supermarkets.

 

 

Q. After reading this article, I realise it is unlikely that I have a true

food allergy but I think I may have an intolerance to a particular food.

Should I stop eating this food?

 

A. Removing a food or an entire food group from your diet may leave you with

an unbalanced diet, possibly causing you to miss out on essential nutrients

you need each day to stay healthy. There may also be other medical reasons

for the symptoms you are experiencing, rather than your diet.

 

Before jumping to conclusions, consult your doctor to rule out that a

medical condition is not the culprit. If food appears to be implicated, you

should be referred to an Accredited Practising Dietitian (APD) or a

Registered Dietitian who will provide professional guidance to identify the

problem food/s without restricting your diet unnecessarily.

 

If a true food allergy is suspected you will need to get a referral to a

specialist allergy doctor for further testing.

 

For more information

 

To find an Accredited Practising Dietitian in Australia call 1800 812 942 or

visit www.daa.asn.au

To find a Registered Dietitian in New Zealand go to the New Zealand Dietetic

Association website at www.dietitians.org.nz

Visit the Royal Prince Alfred Hospital Allergy Unit website at

www.cs.nsw.gov.au/rpa/allergy

Visit the Coeliac society website for Australia at www.coeliac.org.au or New

Zealand www.coeliac.co.nz

 

Swain AR, Soutter VL and Loblay RH, 2004. Friendly Food - the essential

guide to avoiding allergies, additives and problem chemicals. Murdoch Books,

Australia.

Mullins RJ, October 2004. ASCIA Position Statement: Unorthodox Techniques

for the Diagnosis and Treatment of Allergy, Asthma and Immune Disorders.

Accessed from: http://www.allergy.org.au/pospapers/unorthodox.htm

Information about coeliac disease. Accessed from the Coeliac Society of

Australia http://www.coeliac.org.au/whatcd.htm 6th January 2005.

 

This feature story was written by Carolyn Lincoln APD and reviewed by Dr

Anne Swaine, Royal Prince Alfred Hospital Allergy Unit, Australia.