Friday, 16 January 2009

FOOD ALLERGIES AND INTOLERANCE


“In nothing do men more nearly approach the gods than in giving health to men.” - Cicero

I was speaking to a family friend the other day and she was talking about her food intolerance and how adversely it affects her life. She constantly has to be on her guard because if she consumes any of the foods that cause her distress, it can lead to an extremely unpleasant set of consequences that make her life miserable. One the things that she always had to do is read very carefully the ingredients list on all packaged avoiding those that contain the offending foodstuffs. Other acquaintances suffer from food allergies, with rather dramatic and even more dangerous consequences than those of a simpler intolerance. Contrary to popular belief, food allergies are rare. Most reactions to food are an intolerance. The symptoms of allergies and intolerances usually affect three main sites of the body, the skin, the respiratory and the digestive systems.
Allergies are an over-reaction of the body’s immune system to a specific component, usually a protein. These proteins may be from foods, pollens, house dust, animal hair or moulds and these substances are known as allergens. The word ‘allergy’ means that the immune system has responded to a harmless substance as if it were toxic. Allergic reactions occur in genetically predisposed people, which explain why “one man’s meat is another man’s poison”…

Food intolerance is a specific adverse reaction that some people have after eating or drinking; it is not an immune response. Food intolerance has been associated with asthma, Chronic Fatigue Syndrome and Irritable Bowel Syndrome. Food intolerance is much more common than food allergy. Food intolerances also have a genetic component and in some cases are associated with abnormal metabolic reactions occurring because some metabolic pathway in the body is somehow compromised. The symptoms of food allergies are often difficult to distinguish from those of intolerance. As these symptoms can also be caused by other conditions, medical diagnosis is always needed.

Symptoms of food intolerance may be immediate or delayed and are often triggered only after a threshold level of exposure is reached. They can include the following: Nervousness, tremor; sweating, palpitations, rapid breathing, headache, migraine, diarrhoea, burning sensations on the skin, tightness across the face and chest, allergy-like reactions due to histamine and other amines in some foods, asthma from food containing benzoates, salicylates, MSG and sulphite derivatives.

Symptoms of food allergy tend to be more immediate and can be life-threatening. Common symptoms include: Itching, burning and swelling around the mouth, runny nose, skin rash and hives, eczema, urticaria (skin becomes red and raised), diarrhoea, abdominal cramps breathing difficulties, including wheezing and asthma, vomiting, nausea, life-threatening anaphylaxis.

Allergies are on the increase worldwide and in recent times, food allergies have become more prevalent, particularly peanut allergy in preschool children. In June 2002, 6.2% of preschool children in NSW had a food allergy, with the reported prevalence of peanut and nut allergy at less than 2 per cent. About 60 per cent of allergies appear during the first year of life, with cow’s milk allergy being one of the most common in early childhood. Most children grow out of it before they start school. Less than one per cent of adults have food allergy. About 90% of allergies are caused by nuts, eggs, milk or soy. Peanut allergy is one of the most common allergies in older children. Other foods that cause allergies include (in order from the most common):
* Egg
* Peanut
* Milk
* Other nuts
* Sesame
* Fish
* Grains such as rye, wheat, oats
* Soy
* Molluscs, such as oysters, mussels, clam, squid and octopus
* Crustaceans, such as lobster, prawn, crab, shrimp
* Fruit, berries, tomato, cucumber, white potato or mustard.

The foods that tend to cause intolerance reactions in sensitive people include:
* Dairy products, including milk, cheese and yoghurt
* Chocolate
* Egg, particularly egg white
* Flavour enhancers such as MSG (monosodium glutamate)
* Food additives
* Strawberries, citrus fruits and tomatoes
* Wine, particularly red wine.

Reactions may not always occur, as they are usually related to the amount of food consumed. A small amount may not cause any reaction. In most cases, symptoms appear within a few minutes of eating the particular food, which makes pinpointing the allergen an easy task. However, if the cause is unknown, diagnostic tests may be needed such as:
* Keeping a food and symptoms diary to check for patterns.
* Cutting out all suspect foods for two weeks, then reintroducing them one at a time to test for reactions (except in cases of anaphylaxis).
* Skin prick tests using food extracts.
* Blood tests.

The easiest way to treat a food allergy or intolerance is to eliminate it from the diet. Sometimes, the body can tolerate the food if it is avoided for a time, then reintroduced in small doses. Before you eliminate foods from your diet, seek advice from a doctor or dietitian. In Australia, the December 2002 Food Standards Code requires food labelling to declare certain substances in foods and certain foods including:
* Cereals containing gluten and their products
* Crustacea and their products
* Egg and egg products
* Fish and fish products
* Milk and milk products
* Nuts and sesame seeds and their products
* Peanuts and soybeans, and their products
* Added sulphites in concentrations of 10mg/kg or more
* Royal Jelly presented as food or present in food, bee pollen and propolis.

These foods must be declared whenever they are used as an ingredient or part of a compound ingredient (even if they are carry-over ingredients); a food additive or compound of a food additive; a processing aid or component of a processing aid.

All foods produced after December 2002 must bear labels that comply with new labelling laws. To avoid allergic foods, learn the terms used to describe these foods on foods labels, for example:
* Milk protein - milk, non-fat milk solids, cheese, yoghurt, caseinates, whey, lactose.
* Lactose - milk, lactose.
* Egg - eggs, egg albumen, egg yolk, egg lecithin
* Gluten - wheat, barley, rye, triticale, wheat bran, malt, oats, cornflour, oatbran.
* Soy -soybeans, hydrolysed vegetable protein, soy protein isolate, soy lecithin.
* Salicylates - strawberries and tomatoes.

Your doctor and a dietician may be able to help you live a more or less normal life even if you have a serious allergy, but it vey definitely a case where your health and well-being lies squarely in your own hands and you have to take responsibility personally.

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