Food intolerance is common in the modern world, as it may affect up to 15–20% of the population. Adverse reactions to foods can be broadly divided in to those with an immune basis — food allergies and coeliac disease, or those without an immune basis — termed food intolerances;
Food intolerance is a term widely used to describe a variety of reactions that some people have after eating or drinking certain foods;
Food intolerance is NOT food allergy. So unlike food allergy it is not caused by your immune system reacting to the food;
Food allergy and food intolerance are commonly confused as some of the symptoms and trigger foods can be similar;
What are the types of food intolerance?
Children may be intolerant to certain substances found in a variety of food and drinks. Here is a small list of foods to which children are intolerant: milk and other dairy products, chocolate, food additives (including monosodium glutamate or MSG), strawberries, citrus fruit, tomatoes, egg, nuts, fish, wheat and soy;
Unlike food allergy, intolerance reactions get worse the more food or drink is consumed. Thus, some children may be able to cope with small amounts of the foods that they are intolerant to, but they will not be able to tolerate larger amounts of the same food;
What are the common symptoms of food intolerance?
Intolerance reactions are generally less severe than allergic reactions and are unlikely to be life threatening. This does not make intolerance reactions less painful;
The common symptoms of food intolerance include stomach or bowel problems (such as reflux, colic, vomiting, diarrhoea, bloating, irritability), disturbed sleep, heartburn, skin rashes, eczema and hives;
Food intolerance may also be associated with conditions like asthma, chronic fatigue syndrome and irritable bowel syndrome;
Symptoms of food intolerance are often delayed and may occur several hours (up to 48 hours) after consuming the trigger food;
Can you provide us with some examples of food intolerances?
Sure: some substances found in foods are poorly absorbed by children as well as adults. Specialists use the word FODMAPs as an abbreviation that describes some of these substances which can result in intolerance symptoms;
FODMAP stands for:
Fermentable
Oligosaccharides (e.g. fructans and galactans)
Disaccharides (e.g. lactose)
Monosaccharides (e.g. excess fructose) and
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Polyols (e.g. sorbitol, mannitol, maltitol, xylitol and isomalt);
Some children have trouble digesting more than one of these substances such as fructose and lactose. Other children may find that their symptoms improve when they decrease how often they eat these foods or take a smaller amount of it. Usually these foods do not have to be eliminated completely, just offer your child a smaller portion of the culprit food;
How do I recognize that my child has intolerance to the substances in FODMAP?
Your child may complain of bloating, passes an excessive amount of gas, compains of abdominal pain, or has diarrhoea or even constipation;
Can you provide examples of food which contain these substances?
Fructose is a sugar found in fruits. Certain fruits contain a large amount of fructose. These include apples, pears, mango and water melon. Fructose is also found in high amounts in honey, fruit juice and artichokes besides other foods;
Fructans are substances consisting of a chain of the sugar found in fruit called fructose with a glucose molecule at the end. There is no human enzyme capable of breaking down fructans and as a result, they are not absorbed by the gut. Furthermore, they easily ferment in the gut and they resulting in gas production. This gas is likely a significant contributor to bloating, abdominal pain, and excessive flatus seen in IBS. Because of this process of fermentation which may take some time to occur the symptoms may not appear immediately but occur a few hours later. They are found in artichokes besides garlic, leeks, onion (and garlic powder), ripe bananas, barley and rye together with wheat and its products such as bread or pasta. It is also found in corn syrup;
Lactose: lactose is the sugar which gives milk its good taste. Thus your child may develop symptoms when they take cow’s milk, ice-cream, custard and yoghurt besides products made from milk such as soft cheeses ( ricotta and cottage cheese amongst others) but not hard cheeses;
Galacto-oligosaccharides: are prebiotics made up of a chain of yet another sugar this time by the name galactose. They are found in legumes such as baked beans, kidney beans and borlotti beans. They are also found in lentils and chickpeas. As such galacto-olisaccharides are beneficial even to newborns as they support the natural defenses of the human body via the bacteria in the gut. They also displace bacteria which are harmful including E coli and Salmonella amongst others. E coli and Salmonella can cause severe bacterial gastroenteritis;
Polyols: these are sugar alcohols found in certain fruits, vegetables, and sugar-free sweeteners. Foods containing a substantial amounts of polyols include apples, cherries, nectarines, pears. plums and peaches. They are also found in cauliflower and mushrooms;
Lactose is the main carbohydrate taken by the baby soon after birth. There is at least 7% lactose in breast milk. In most humans, lactase (the enzyme which breaks down lactose) decreases after weaning and your child will develop abdominal pain, cramping, distention, flatulence, diarrhea, nausea, and occasional vomiting after consuming lactose-containing dairy products;
Lactose intolerance occurs when a person is unable to digest lactose, the sugar found in cow’s milk and other cow’s milk products such as yoghurt besides breast milk. Lactose intolerance can be temporary and some children may grow out it;
He might tolerate small amounts of lactose, but if he takes large amounts of lactose he may have loose stools and tummy pain. It is thus advisable that you avoid presenting him with large amounts of cow’s milk and yoghurt. The solution is to to use lactose-free milk and yoghurt (or soy milk and yoghurt) instead;
Lactose intolerant children can eat regular hard cheese (such as cheddar and parmesan) which has almost no lactose and should be tolerated by most people with lactose intolerance;
Fructose is the sugar found in fruits and certain vegatables. If your child is suffering from fructose intolerance he will suffer from diarrhoea, wind, bloating and tummy pain;
He/she do not need to avoid all fruit. Rather he/she should take a smaller portion of fruit that triggers his/her symptoms, and replace it with fruit that they tolerate better;
Do not stop fruit altogether as fruit is an important part of your child’s diet. Use fruit which contain less fructose : oranges, grapes, kiwi, oranges and mandarin etc;
Fructan and galactan malabsorption:
Fructans and galactans are carbohydrates that are malabsorbed by all people to some extent. However, children can tolerate different levels of these molecules and some children will experience symptoms when eating amounts that are well tolerated by others.
Fructans and galactans are found in foods such as onion, garlic, leek, large amounts of wheat and legumes (e.g. baked beans, lentils, chickpeas). You do not need to completely remove them from your child’s the diet (although onion, garlic and legumes can be particularly problematic);
These substances are also found in wheat and its products. You will need to limit foods which contain wheat as the main ingredient. These include bread and pasta. You can still use flour as a thickener in sauce because the amounts are fairly small;
Food additives and chemicals:
The modern food industry uses a number of chemicals as preservatives and flavour enhancers. The preservatives include sorbates which are found in margarine, dips, cakes and fruit products. Another group of preservatives are benzoates which are added to juices, soft drinks, cordials, syrups and medications. Sulphites are found in dried fruit, fruit drinks, sausages and many other products. Propionates including cultured whey/dextrose are found in bread, crumpets and bakery products. Last, but not least, are nitrates and nitrites which are widely used in processed meats such as ham and bacon;
Flavour enhancers care utilized to improve the taste of food and they can also cause intolerance reactions. These include MSG, hydrolysed vegetable protein, yeast extract, disodium inosinate, disodium guanylate and ribonucleotides. These chemicals can be the cause of intolerance reactions in different individuals. These symptoms can include headaches, hyperactive behaviour, mood swings, anxiety, depression, panic attacks, difficulty concentrating, fatigue, learning difficulties, toileting challenges and joint pain amongst others;
How do I look after my child with food intolerance?
It is crucial that if your child is intolerant to foods which contribute important nutrients for their growth and development are offered other substitutes. Ensure that you don’t avoid food without good reason;
Thus one can substitute rice for wheat if your child is intolerant to pasta. Use banana which is not too ripe, use a smaller amount of onion, cook broccoli and cauliflower for a shorter time: not more than 6 minutes. As regards fruit substitute apples to oranges or strawberries. Use lactose free milk if you are intolerant to lactose.
It is crucial to be guided by your GP/Pediatrician or by a nutritionist before embarking on a low-FODMAP diet as this is restrictive and can result in more harm than good. Substituting one food group for another may result in inadequate intake of nutrients particularly iron, vitamin B as well as carbohydrates and fibres. Both a nutritionist and paediatrician’s input are necessary the former to guide in the diet while the latter will monitor progress as well as growth;
What about blood tests?
We read and hear a lot about blood tests utilized to diagnose food intolerance. I wish to reiterate the point that food intolerance is NOT food allergy. Although food intolerance tests are advertized there is NO proof that they help whether they are touted as ELISA or whatever;
Many experts in the field of food intolerance emphasize that food exclusion to achieve symptom improvement followed by gradual food reintroduction is still the best diagnostic test;
The American Academy of Allergy, Asthma & Immunology states that IgG and IgG subclass antibody tests for food allergy do not have clinical relevance, are not validated, lack sufficient quality control, and should not be performed. The same view is taken by the Canadian and the corresponding European academies;
A simple example may clarify this: you can have the most accurate speedometer in your car but using it to gauge whether the radiator needs topping up is clealy not useful!
DO NOT place your child on a restricticted diet based on these blood tests;
The gold standard test for food intolerance is to exclude food found in FODMAP which should cause symptom improvement. This will be followed by the gradual food re-introduction with return of symptoms. Of course, this takes time and this may be the reason why parents resort to blood tests which will mislead the parents to place their child on an exclusion diet;
You may exclude one type of food and substitute for an equivalent. Those who are intolerant to lactose can use lactose free milk. Cook more rice recipes if your child is intolerant to wheat etc;
If your child is intolerant to a wide range of food then dietitian-led education is superior in clinical response to brief education with food lists. Use of the above lists alone is clearly inferior to guidance from a FODMAP-trained dietician;
Take home message
Food intolerance is quite common in both adults and children.
Food intolerance is NOT food allergy;
Refrain from taking a shortcut by requesting blood tests which are at best misleading and at worst lead to nutrient deficiency.
Many adults and children avoid foods which lead to bloating and abdominal pain without the need for a dietician.
DO take the advise of a dietician if you find that your child is intolerant to a variety of different foods.
References
Lomer, M.C., 2015. The aetiology, diagnosis, mechanisms and clinical evidence for food intolerance. Alimentary pharmacology & therapeutics, 41(3), pp.262–275.
Rhys-Jones, D., Varney, J.E., Muir, J.G., Gibson, P.R. and Halmos, E.P., 2022. Application of The FODMAP Diet in a Paediatric Setting. Nutrients, 14(20), p.4369.
Tuck, C.J., Biesiekierski, J.R., Schmid-Grendelmeier, P. and Pohl, D., 2019. Food intolerances. Nutrients, 11(7), p.1684.
Disclaimer
The information in this Blog is provided for educational purposes only. It is not intended as medical advice. Kindly consult your family doctor or your paediatrician if you have any concerns about your child’s health.
Copyright
Copyright Dr. Eugenio Azzopardi, Consultant in Paediatric Emergency Medicine. All rights reserved.
