By Sabine Spiesser BS, Grad Dip Dietetics.
April, 2001
Diagnosis
Treatment
Further reading and links
Elements of an individual action plan
Disclaimer | About the author:
Many people with CFS believe that they react adversely to some foods. Although there are no good statistics about this, the experience of dietitians in the field, and information from the ME/CFS Society of SA, suggests that possibly 20 to 30% of people with CFS are so affected.
There are many ways that food can cause reactions, including true food allergy, and more commonly, a drug-like intolerance to natural or added food chemicals. Some people with CFS may also experience problems with maldigestion or malabsorption of food.
Neither food allergies nor food intolerances are trivial, as they can cause tremendous discomfort for sufferers. A true food allergy can be life-threatening in some cases. Most reactions however, are less severe.
A true food allergy involves the body's immune system. This occurs when a food allergen, which is usually a protein or sequence of amino acids, enters the body and stimulates food-specific antibodies, known as IgE antibodies. These antibodies are located on the outside of mast cells or basophils, which are part of the immune system, and when stimulated, trigger these cells to release histamine, thereby causing the symptoms. Some allergic reactions can occur when non-protein substances attach to proteins and form an allergen, e.g. nickel allergy.
Not all reactions are due to contact with allergens. Mast cells can also respond to other stimuli, such as heat, cold, exercise etc..
Allergens and antibodies are food specific, just as lock and key are specific for each other. The severity and location of a reaction depends on the amount of food eaten, the form of the food, food processing, exercise, the sensitivity of an individual, and the quantity of histamine and other chemicals released. Sometimes minute traces of food left on equipment or contaminating other foods can cause very severe reactions. Everybody with a food allergy should have a written individual action plan developed by their doctor. Do not assume that all doctors are familiar with food allergies, anaphylaxis or other food reactions.
While most allergic reactions to food are relatively mild, a small percentage of food-allergic individuals have severe life-threatening reactions. Anaphylaxis is a rare but potentially fatal condition in which several different parts of the body experience food-allergic reactions simultaneously, causing hives, swelling of the tongue and throat, difficulty in breathing, heart and blood pressure as well as gastrointestinal problems. Affected people need to carry syringes loaded with epinephrine (adrenaline) for immediate self-injection (Epi-Pen) as well as medic alert bracelets.
Reaction time varies from a few minutes (early) to a few hours (delayed) to a few days (late response). In anaphylaxis an immediate type of reaction is often followed by a delayed one, making a visit to an emergency centre vital.
Anaphylactic shock is the most severe allergic reaction, involving many organs of the body, including the:
- Nose - sneezing, blocking, watering and runny nose
- Upper airways - swelling of the throat and vocal cords leading to obstruction of breathing, blue lips indicating oxygen deficiency
- Lungs - wheezing and asthma
- Skin - itching hives (urticaria)
- Circulatory system - a fall in blood pressure and collapse.
Food allergies and intolerances can cause range of symptoms in different parts of the body, including:
- Gastrointestinal system: Abdominal bloating, flatulence, cramps, pain, colic, nausea, vomiting, diarrhoea, anorexia (loss of appetite), early satiety, rectal burning, IBS. Food allergy may be a cause in about 10% - 15% of colicky infants.
- Skin: Itchy rash, redness, eczema, hives, welts, local swelling
- Respiratory system: Coughing, wheezing, asthma , nasal congestion, itchy and runny nose, sore throat, hay-fever, difficulty speaking
- Face: Itching eyes, swelling of lips, throat and tongue
- Cardiovascular system: Rapid thumping heartbeat, dizziness, fainting, collapse, low blood pressure, pale & floppy infant
- General: Anaphylaxis, fatigue, fever, flushing, sweating, muscle aches
- Neurological: Headache, irritability, dizziness, faintness, drowsiness, loss of consciousness, hypoglycaemia type symptoms.
Symptoms of a food allergy are highly personal and usually begin within minutes to a few hours after having eaten the offending food. Immediate reactions are usually obvious, but any other reaction needs further investigation. Usually, people are truly allergic to only one or two foods. Food allergy is more common in children, and many children grow out of their allergies over time.
The most common food allergens are milk, soy,wheat, egg, fish, shellfish, peanuts, and tree nuts such as walnuts. However, all foods contain proteins, which can potentially act as antigens. Sometimes patients allergic to latex also react to certain foods such as avocados, bananas, kiwis or chestnuts. Reactions are also possible between botanically related or unrelated foods. This is termed Cross-Reactivity.
In Oral Allergy Syndrome, individuals react to uncooked foods with mouth and throat itching or swelling. Fresh fruits, nuts and vegetables are often the culprits. These reactions are brief and believed to be due to pollen protein cross-reacting with proteins found in fruits and vegetables. Often reactions are to other members of the same botanical family. The responsible proteins [profilins] are inactivated by cooking. For example, persons sensitive to birch tree pollen may react to fresh apples. The same people, however, might tolerate cooked apples, as in apple sauce. More serious allergic reactions can occur, if exercise is undertaken soon after eating a lot of this type of food. Occasionally individuals are allergic to many different fruits and vegetables.
Examples of cross-reactivity
| Allergen | Foods |
| Ragweed Pollen | Melons, banana, chamomile |
| Birch pollen | Apple, carrot, hazelnut, potato, almond |
| Mugwort pollen | Celery, apple, kiwi |
| Latex | Banana, kiwi, avocado, chestnut |
Exercise Induced Anaphylaxis In this condition, individuals develop itching, rashes, angioedema and upper airway obstruction with bronchospasm during or shortly after strenuous exercise taking place within a few hours of eating certain foods. This allergic condition may occur up to 12 hours after eating wheat, celery and shellfish, especially prawn. These patients have no reaction to the foods if at rest.
Food intolerance is an adverse reaction to food which does not involve the body's immune system. These reactions are called pharmacologic reactions because the culprit substances behave like drugs, possibly acting on the nervous system. In adults, this sort of reaction is far more common than true food allergy, and the incidence seems to be increasing.
The symptoms of pharmacological food intolerance can be the same as symptoms of food allergy eg hives, swelling, eczema, headaches, asthma and other respiratory tract symptoms, bowel symptoms, and cognitive disturbance.
The severity of the reactions depends on the dose eaten, as well as other chemicals consumed at the same time, and other factors such as stress , hormone levels (eg women often are more reactive before menstruation), and use of other medications (especially NSAIDs). Food intolerance reactions can be caused by both added and natural substances in foods. Most people have no problems consuming these natural food substances and additives - reactions occur in individuals who happen to be more sensitive. Reactions are becoming more common to the increased ingestion of these substances in processed foods. Common offenders are:
It can be very difficult for people to identify food intolerances, because reactions can be inconsistent (depending on the dose eaten), can be delayed and build up over many days, individuals can react to several different food chemicals, and each food chemical can be found in many different foods, all contributing to the total dose.
Severe reactions similar to anaphylaxis can occur in response to ingestion of food chemicals. These reactions are called Anaphylactoid reactions. Metabisulphite or sulphur dioxide induced asthma is an example of such a reaction.
Other food ingredients capable of causing allergy or gut irritation:
Anaphylactoid reactions to food chemicals are anaphylaxis-like reactions, but don’t involve antibodies. Metabisulphite or sulphur dioxide induced asthma is an example of such a reaction.
Histamine, and histamine-like substances called amines, occur naturally in foods, and can trigger symptoms that mimic allergy. This is particularly true of fermented foods that contain high quantities of the vasoactive amines such as Histamine, Phenylethylamine, Serotonin, Tyramine, and Dopamine. Vasoactive substances affect the diameter of blood vessels (vasodilating = widening, vasoconstricting = narrowing). Amines can act directly on small blood vessels to expand their capacity, perhaps accounting for their effects such as flushing, migraines and nasal congestion in some patients.
Common symptoms of vasoactive amine ingestion are abdominal cramping, flushing, headache, palpitations and hypotension. The symptoms are usually dose related, and occur when the enzyme that metabolises amines, diamine oxidase, does not work well enough to metabolise the amines ingested, or to handle high levels of amines when eaten in large amounts. Symptoms are worse in sensitive people with low levels of enzymes or if alcohol is consumed at the same time. Certain food chemicals such as benzoates, HBA, HBT, the food colour tartrazine, salicylates, nitrates and sulphites can inhibit these enzymes.
Certain non-histamine containing foods, and food chemicals, can trigger direct histamine release from mast cells. IgE is not involved in the reaction and specific IgE antibodies to these foods are not elevated. Foods that have been implicated in this type of reaction include: raw egg white, shellfish, strawberries, chocolate, citrus fruit, pineapple, tomatoes, alcohol, fish and pork meat, as well as salicylates and metabisulphites. The histamine liberated in this reaction will cause symptoms that may mimic true food allergy.
Some amines are metabolised by an enzyme called monoamine oxidase. People taking specific anti-depressant medications called monoamine oxidase inhibitors ( MAOIs) need to follow a special diet avoiding foods containing monoamines: tyramine and dopamine. That is why if you are on these drugs you will have been told you must not eat many of the foods in the table below.
Foods containing vaso-active amines (Please note, this is an abbreviated list, for full details please visit Allergydietitian )
| Histamine | Tyramine | Dopamine | Serotonin | Phenylethylamine |
| Banana Beef Beer Cheese-yellow ripened Chicken liver Egg Plant, Aubergine Fish, all, fresh, frozen, canned Meat, all processed Salami Sauerkraut Soya and Soy products (fermented) Spinach Strawberry Tamari Tomato Tomato sauce, puree Wines , all Yeast |
Beans- fermented Beer Bovril, Bonox, Camembert Yeast extracts: Vegemite, Marmite, Cheese-Ripened Chicken Liver Cured, processed meat Dried Milk Egg Plant Fava Bean, Broad Beans Orange, Citrus fruit Pickled Herring Sauerkraut Soy sauce, Miso, Tempeh Wine Yoghurt |
Avocado Banana Broad, Fava Bean |
Avocado Banana Kiwi Octopus/squid Pawpaw Pecan Pineapple Plantain Plum Tomato Walnut |
Cheesecake Cheese-yellow Cherry Mushroom Raspberry Pie filling, Chocolate Cocoa Red wine Redcurrant Pie filling Strawberry, canned |
| Tryptamine: Cheese, Tomato | ||||
| Octopamine: citrus fruit | ||||
| Histamine releasing foods: Raw egg white, shellfish, strawberries, chocolate, citrus fruit, pineapple, tomatoes, alcohol, fish and pork meat | ||||
| Enzyme inhibitors: benzoates, HBA, HBT, the food colour tartrazine, salicylates, nitrates and sulphites | ||||
Certain food components, when ingested in large amounts, cannot be digested properly, in the small intestine water is attracted to dilute their concentration and they rapidly pass into the large intestine where bacteria feed on them. This can lead to bloating, flatulence and diarrhoea. The most common culprits are fructose and the sugar alcohols, sorbitol, xylitol and mannitol.
Food poisoning is caused by plant toxins such as aflotoxins in mouldy peanuts or soya beans, and bacterial micro-organisms in food, such as salmonella in chicken and bacterial toxins in uncooked meats and certain fish. Food hygiene in the home and care with shopping, transport and proper storage are vital in preventing contamination and bacterial growth. In some instances, food poisoning can mimic an allergic reaction. For example, in scombroid fish poisoning, spoiled tuna or other fish contain large amounts of histamine produced by contaminating bacteria. When the spoiled fish is consumed, symptoms develop that closely resemble an allergic reaction to food. This is the most probable cause of gastro after a restaurant fish meal.
Enzyme deficiencies may sometimes be mistaken for food allergies or intolerances. However, it is important that they are distinguished from food allergies, to enable appropriate treatment.
Coeliac disease is an inherited immune disease, which does not involve IgE. In coeliac disease, the intestinal mucosa is damaged (flattened villi) by exposure to gluten, a protein found in wheat, rye, barley, oats, triticale and all their products. Diagnosis is by endoscopy and biopsy, after screening tests (Antigliadin IgG, IgA and antiendomysial antibody tests). The procedure is not painful, and is done on a day-patient basis.
If you suspect that you have coeliac disease, it is vital that you do not start a trial wheat free diet. Coeliac disease is a serious condition with many adverse side effects; for a proper diagnosis, you must eat plenty of wheat prior to an endoscopy and biopsy. Only then can the damage to the small intestine be seen.
Coeliac disease is usually diagnosed in early childhood but may be first diagnosed in adults. Coeliac disease symptoms vary, including diarrhoea, abdominal distension, failure to thrive, weight loss and occasionally nausea and vomiting. Often symptoms are not very specific and the disease is diagnosed by chance. Adults can present without the usual symptoms, fatigue being at times the only sign. The only treatment is life-long complete avoidance of all gluten containing foods. This is vital in the prevention of gastrointestinal malignancy.
A negative small intestinal biopsy rules out coeliac disease if it was done while consuming a high gluten diet. It is still possible to be allergic or intolerant to wheat, and not have coeliac disease, as wheat contains a large number of proteins, every one of them potential allergens.
Food aversion is a psychological condition where a person has a reaction, caused by emotions associated with food. This reaction does not occur if the food is given in a disguised form.
The most commonly used diagnostic test in Food Allergy is Skin Prick and RAST (blood test) with Food Allergens. The negative predictive value of food allergy testing is good - if a test is negative, then there is a 95% chance of there being no allergy to that food, but the positive predictive value is less specific - a positive test requires a challenge with the food for diagnosis.
Skin prick tests have no place in the diagnosis of food intolerances.
Food intolerances are diagnosed by an elimination diet, followed by food challenges and gradual re-introduction of foods and food chemicals. Make sure to seek help from a dietitian familiar with this process, and who hopefully is familiar with CFS. The type of elimination diet depends on your symptoms and the severity of your reactions.Do not just eliminate foods you believe to be responsible for your symptoms, as this is most likely not a correct diagnosis. Dietitians look for foods with certain natural or added chemicals. A strict elimination diet is followed for a limited period of time, usually 3 weeks, maximum 4-6 weeks. Foods and food chemicals are then re-introduced in an organized way to enable diagnosis of culprits. If no improvement was seen after 4-6 weeks, food is not considered the culprit and the diet can be aborted. Other causes need to be explored for your symptoms. Individuals with CFS often comment, that their "food allergies" tend to change. This is not correct, what they are most likely experiencing is a food intolerance with fluctuations with dose variations of food chemicals, hence the need for a systematic professionally supervised approach. Many people limit their diet unnecessarily with resultant inadequate intake of vitamins, minerals, antioxidants etc.
Before you make an appointment, be sure to keep a food and symptom diary, preferably in table format. Record every bite and sip crossing your lips. This is most important in tracking possible patterns. It also helps to rate the symptoms, as you can easily forget how severe the symptoms were when you feel better. If you are accurate in portion size and food description, you could have your food intake analysed for nutritional adequacy. It is vital to keep a diary while challenging and re-introducing foods. Always make sure the dietitian is accessible (phone or e-mail) in case you need assistance.
Follow the diet strictly without interruption. If your symptoms do not start to improve within 14 – 21 days, re-introduce foods. You can then eliminate the foods eaten during the diet to make sure they were not the culprits. If symptoms persist, other causes need to be looked into. Some people experience ‘withdrawal reactions" in the first week on an elimination diet, but improve after that, so don’t give up too soon!. Sensitivity to fumes and other environmental chemicals may also increase during this time.
It is important to emphasize that "elimination diets" are prescribed like we do a medication: short term, under supervision, and only for very good reasons. Long term restricted diets are dangerous and can lead to malnutrition, particularly in children.
| Time | Food eaten | Amount | Brand names | Medications | Symptoms | Rate | ||||
| 1 | 2 | 3 | 4 | 5 | ||||||
Treatment in food allergies requires the complete elimination of culprit foods, and the use of antihistamines and other medications as prescribed by the doctor. In food intolerance, the reactions are dose dependent, and the tolerance level needs to be established. Fortunately, the tolerance level can gradually be increased over time. It is vital that you seek help from a dietitian in developing an eating plan as well as making food choices to prevent Hidden Food Allergens. Foods labels can contain a variety of names for a specific food. Foods can be contaminated by unknown foods. Never be satisfied with the statement: "you need to just eliminate xyz." Detailed instructions of which foods to include/avoid as well as possible hidden allergen sources are vital. If major foods are eliminated, a dietitian will need to offer advice on how to obtain the missing nutrients.
| An example: Reaction to green
capsicum. Capsicum contains several possible reactive chemicals: histamine, salicylates, capsaicin, chavicine. There are several questions waiting to be answered:
Avoidance of "capsicum" is, in practice, not as easy as it sounds. |
Contents
Food Allergy and Food Intolerance Information Site from Allergydietitian. The author's website.
FACTS: Food Anaphylaxic Children Training and Support Association Aussie site
Australian Society of Clinical Immunology and Allergy Aussie site
Milk Allergy Support Group - Information on milk allergy and lactose intolerance Aussie site
www.NoMilk.com - The No Milk Page
- lots of links
Allergy Society of South Africa - Great website to search for any info related to allergies
The Food Allergy and Anaphylaxis Alliance
- American patient support organization
The Celiac Disease & Gluten-Free Diet Support Page
Quackwatch - Dr. Stephen Bennett’s website on health quackery
Doctor's Guide - Up to date medical information.
About.com's Allergies pages - Lots of links to allergy websites
J. Brostoff and Linda Gamlin The Complete Guide to Food Allergy and Intolerance, London, Bloomsbury, 2000,
John Emsley, Peter Fell Was it something you ate? Food intolerance, what causes it and how to avoid it. Oxford University Press, 1999
Ardys Zoellner The SNAK (Sensitive New Age Kitchen), 80 recipes FREE of dairy, wheat, eggs & sugar - available through FACTS
Maurice Hanssen The new additive code breaker, Lothian books, 1999
AR Swain, VL Soutter, RH Loblay (Royal Prince Alfred Hospital Allergy Unit) Friendly foods, Murdoch Books, 1998
Joan Breakey Are you food sensitive?
The individual action plan should include detailed instructions on….
This article has been written for people wanting to obtain some general information of food induced reactions. Readers are cautioned against self-diagnosis and self-treatment based on the limited information provided. This article is not a substitute for professional assessment by allergists/immunologists or dietitians. If you suspect that you might be reacting to food, please consult a specialist. No responsibility is taken by the author for the consequences of treatment initiated by patients who have not been seen by me in consultation. The knowledge in this document reflects general current knowledge and may become outdated as new research information surfaces. Many of the symptoms mentioned in the paper are not specific to food reactions, but general symptoms experienced in a variety of organic diseases. I strongly advise individuals to consult their doctor for a thorough medical check-up prior to any further investigation.
Sabine Spiesser is a dietitian with a private practice in Melbourne. Her special fields of interest are food intolerance/allergies, gastrointestinal problems and eating disorders. She has had CFS/FMS for many years.
For appointments please call:
Glen Waverley Dietetic Consultancy
Tel 03 9561 5342, Fax: 9561 6482
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last revised 19 Aug 2002