Asthma and Food

Asthma and Food (PDF)

The role of diet in asthma control is still unclear.  Therefore, changes to diet should only be made with the advice of a dietitian to ensure a healthy well-balanced plan. To date there is no proof that any food or food group can prevent asthma. 

Food is rarely a trigger for asthma but may cause severe attacks in a small group of people with food allergy or chemical intolerance. True food allergies occur in only 6 – 8% of children and 1 – 2% of adults.

What is Food Allergy?

A food allergy occurs as a result of an overactive immune system that treats harmless visitors to the body as dangerous invaders.  When the body sees particular foods as “invaders” it makes antibodies against them.  This sets off a series of reactions that may include:

·      Hives

·      Rashes

·      Vomiting

·      Diarrhoea

·      Tightening and swelling of the airways

·      Swelling of the mucous membranes

These reactions may occur very quickly, sometimes only minutes after eating a certain food.  The reaction may be so severe that hospitalisation is necessary.

Foods that may trigger an allergic reaction include:

·      Peanuts

·      Seafood

·      Eggs

·      Wheat

·      Soy

·      Dairy Foods

True food allergy is more common in young children.  In most cases it is linked to other allergic problems such as eczema.  Most children outgrow food allergies by the age of five.

What is a Food Chemical Intolerance?

All foods are made up of thousands of chemicals.  A small number of these chemicals are known to trigger asthma.  The reactions are slow to start and can be delayed as long as three days.  Food chemical intolerance is a more common problem than food allergy but symptoms are rarely as severe.  Unlike food allergies, food chemical intolerance reactions are “dose dependent”.  That means the more food that is eaten, the more severe the reaction.  People of all ages may be affected and it can worsen with age.

Food chemicals that may trigger asthma include:

·      Sulphites (sulphur dioxide and sodium metabisulphite)

·      Food colours (tartrazine)

·      Monosodium Glutamate (MSG)

·      Salicylates

Sulphites

These are the most common food chemicals to trigger asthma.  They are used in many processed foods to stop fermentation.   They are also added to some fresh foods such as prawns and grapes.  They are numbered 220-228 on labels.

Tartrazine

Tartrazine is an artificial food colouring agent.  It rarely triggers asthma but if it does then all food colouring should be avoided.  Tartrazine is numbered 102 on labels.  Numbers of other food colouring agents are 107, 110, 122-29, 132, 142, 151, 155.

Dairy Foods
People with asthma are often told to avoid dairy products, particularly milk.  Recent research does not support this widely held view.  If you think that you may have an allergy to milk products you should seek advice from a dietician and your doctor.

Monosodium Glutamate (MSG)

MSG is a flavour enhancer. It is found naturally in many foods or may be added during manufacture or cooking. MSG is a food chemical that occurs in high levels in products such as vegemite and soy sauce.  MSG may be added to foods such as savoury flavoured snack foods and some restaurant foods.  It appears on food labels as numbers 620-625.

Hydrolysed Vegetable Protein is often used instead of MSG and has much the same effect in those people sensitive to MSG.

Individuals affected by MSG will usually have a reaction in the form of a sudden severe attack of asthma between 6 to 12 hours after the food has been eaten.  There are usually no symptoms of asthma immediately after consumption.

Research shows that the MSG content in Italian foods may be just as high as or higher than Chinese meals. Many people do not experience asthma symptoms when eating Italian foods.  It is possible that there may be something other than MSG in Asian food that is responsible for the symptoms.

Salicylates

Some people with asthma may have sensitivity to salicylates in aspirin or certain foods.

What is aspirin sensitive asthma?

In about 5-10% of people with asthma, aspirin may trigger symptoms resulting in wheezing or difficulty in breathing. People with this type of asthma usually develop onset of asthma later in life (usually in their thirties or forties). They also often have problems with nasal blockage and nasal polyps. This type of asthma is rare in children.

Extreme cases may result in worsening of symptoms and a potentially life threatening attack. A small proportion of people who have asthma and who are sensitive to aspirin, may also be sensitive to salicylates in food.

Where are salicylates found?

The highest levels of salicylates are found in aspirin.  Salicylates may have similar effects in sensitive individuals when added to other medical preparations eg. in a number of teething gels. Examples of products containing salicylates are Bonjela, Orased Jel, and Seda-gel.

What about salicylates in food?

There are salicylates which occur naturally in some foods (see attached list). A person would need to already have asthma and sensitivity to salicylates to have asthma triggered by them. You will not develop asthma from taking salicylates.

Is there a test for salicylate sensitivity?

It is difficult to test for salicylate sensitivity. There is a formal challenge test, which can be done under medical supervision. See your doctor for details.

What products might affect asthma?
Aspirin or acetylsalicylic acid is freely available from supermarkets and pharmacies, and is widely used for the treatment of pain, fever and inflammation.  It is particularly useful for rheumatic and arthritic conditions as well as for reducing the risks of blood clotting.  Apart from the possibility of severe reactions in some people with asthma, aspirin is a very useful drug that is both safe and effective. Examples of aspirin based products containing salicylates are: Action, Alka-Seltzer, Aspalgin, Aspro, Aspro Clear, Codis, Codox, Disprin, Disprin Forte, Solprin, Veganin.

A number of other NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) available over the counter from pharmacies may also provoke reactions in people with asthma sensitive to aspirin. They are used for pain relief and are frequently used for period pain. Examples of products containing NSAIDs available without a prescription are: Ibuprofen e.g. ACT-3, Actiprofen, Brufen, Codral Forte, Nurofen, Rafen; Mefenamic Acid e.g.  Ponstan; Naproxen e.g. Inza, Naprosyn; Naproxen sodium e.g.  Anaprox, Naprogesic, Diclofenac (Voltaren).                                                                                                          

What should I do if I am affected?

Consult your Asthma Action Plan immediately, take your reliever medication and call an ambulance for urgent medical treatment (continue taking 4 puffs of your reliever medication every 4 minutes).

What can I do to avoid problems?

If you are sensitive to aspirin, choose paracetamol-based products for pain relief and check that any products taken for the relief of symptoms, including colds and flu, do not contain aspirin.

Avoid eating foods that have salicylates in them if you are salicylate sensitive.

Be aware and avoid the common triggers. Have a written action plan worked out with the doctor, and always take worsening symptoms seriously. Make sure children with asthma know the possible dangers of taking aspirin when away from home. They need to be able to make an informed decision on the best pain reliever for them.

Always read the information leaflet and any warning labels on all products. This includes medicines from the pharmacy, supermarket, health food shops and other sources. Whenever consulting anyone about your health, or when you are admitted to hospital, do make sure that you tell them if you have aspirin sensitive asthma.

Please refer to list of foods containing salicylates: