Food allergy and food intolerance – is the reported impact on our psychology real or exaggerated?

Food allergy and food intolerance – is the reported impact on our psychology real or exaggerated?

By Audrey DunnGalvin


Data on the European and global prevalence of food allergy and intolerances suggest that both reported and actual rates are increasing. Food allergy is becoming a major public health concern affecting up to 5% of adults and 8% of children, with food intolerance affecting approximately 20% of adults and children. High levels of anxiety and other adverse outcomes have been linked to both conditions, but there have been questions on whether this impact is ‘real’ or exaggerated?

Before we consider this question, let’s first have a look at one or two misconceptions around food allergy and intolerance that give rise to some scepticism: how many people actually have the conditions ?; and how they are diagnosed ?


Why are reported prevalence rates so high in some studies?

Prevalence rates of from 5 up to 50% are found in prevalence studies. This is due to a) confusion over what constitutes food allergy or food intolerance and to b) the methods used to collect data on prevalence. To be confident of prevalence rates, food allergy or food intolerance should be properly diagnosed by a specialist in the area, using gold standard methods of diagnosis, and then entered into a registry. Tests offered by some pharmacies or alternative practitioners are not valid or reliable and a diet (particularly in a child) should never be changed or a food eliminated, based on such advice.


How is food allergy and food intolerance diagnosed?

Diagnosis of food allergy is straightforward, by means of a food challenge test, with blood or skin tests usually carried out first to help with the diagnosis. In a food challenge test, a tiny sample of the suspected food allergen is offered and the reaction (if any) is then measured. Usually the test is ‘blinded’ which means that the patient does not know if the sample is ‘real’ or a placebo. Clinicians find that patients do report reactions to placebo samples, and this is usually when individuals have been avoiding a certain food for some time based on their perception that they do have a food sensitivity and are worried that they will have a reaction during the test.

Prevalence estimates can also be skewed due to the method of data collection, the population under investigation, the questions asked, how they are worded, and the definition of terms related to food allergy or food intolerance. In some food intolerances the underlying mechanisms are poorly understood, which makes diagnosis more challenging. Diagnosis of a food intolerance often involves a structured process of food elimination with observation and overview from a specialist. Much more is understood about Coeliac disease (an enzyme deficiency) and here a biopsy is used to make a definitive diagnosis.


How does food allergy differ from food intolerance?

‘Food hypersensitivity’ describes all adverse reactions that occur in a person when a food is eaten. Such reactions may be allergic (immune mechanism, i.e. food allergy) or non-allergic (non-immune, i.e food intolerance).

In food allergy, reactions usually occur on initial exposure, from minimal quantities, and range from mild to life-threatening (anaphylaxis), and may affect one and/or every system in the body, including the cardiovascular system. Symptoms of food intolerance most commonly affect the skin or gut, and usually occur some hours after eating the food. Symptoms can range from mild/ moderate (colic, reflux, bloating, constipation) to severe (severe persistent vomiting or diarrhoea, significant blood in stool, and faltering growth in children).


What are the similarities between food allergy and food intolerance?

Although the underlying mechanisms are different, food allergy and food intolerance share more than we think in terms of their effects on our psychology.

It is only relatively recently that the impact of food allergy and food intolerance has been seriously investigated. Numerous studies, using valid and reliable measures show that there is a strong negative impact on quality of life in both conditions, particularly in social and emotional areas. Since a fatal reaction in food allergy is rare and there is no chance of a fatal reaction in food intolerance, why do the conditions have such an adverse effect on everyday lives?

There is no ‘cure’ for food allergy or intolerance – avoidance and constant vigilance is the only treatment offered. Both are ‘invisible’ diseases where you or your child may be completely well for periods of time until an accidental ingestion occurs. An accident is quite likely, even if you are very alert to possible danger because of vague and non-directive labelling, food preparation practices, manufacturing practices and low awareness among the public or food venues.

Therefore, the underlying mechanisms may be different for food allergy and food intolerance, but they do share many aspects which impact on the psychology of those with the conditions.


Food allergy and food intolerance: how real is the psychological impact?

We all know how uncertainty can gnaw away at us – whether it is worry about the economy and our jobs or terrorist threats – where, when, how, if??

Adults, children, parents and families with food allergy or intolerance live with constant uncertainty, including uncertainty around diagnosis (particularly in food intolerance), complexity and confusion about how much of a food you need to eat to have a reaction, and then if you do have a reaction, how severe that reaction will be. Anger, embarrassment, feelings of frustration, fear, anxiety, and stigma have all been reported.

Reactions may occur in social situations and can cause much embarrassment. For example, take the case where Jane, who has an intolerance to several foods, is out enjoying dinner with friends. After being misinformed about the ingredients in a dish, Jane spent all night in the toilet with staff waiting to close the restaurant until the symptoms subsided. Following the reaction Jane has painful symptoms for many days afterwards, missing work and other commitments. Moods may also become unstable due to the impact of the reaction, causing depressive or anxious symptoms. In food allergy, bullying is being increasingly reported in Europe, US, and Australia. To give an example, Katie, a 7 year child with nut allergy, explained how she was chased by a group of classmates with Nutella all over their hands. When she cried with fear, she was told she was just ‘looking for attention’. Children who are bullied are very reluctant to report these incidents.

Globally age differences have been reported with adverse impact increasing as the child’s age increases. Negative experiences give rise to a perception of food allergy as difficult, stressful or embarrassing to live with and manage on an everyday basis. Poor quality of life reported at a young age may contribute to a continuing negative impact on perceptions, anxiety, and risk taking when these children become young adults. Eating, anxiety and mood disorders have also been reported in young adulthood.

So if you think that the impact of food allergy and/or food intolerance is exaggerated, try to imagine the uncertainty of having a reaction constantly hovering at the back of your mind, along with all the other everyday worries, and in the case of children and adolescents, along with the stress of growing up, growing independent, and developing an identity, and perhaps you will think again.


What would help?

Food allergy and food intolerance have a real impact on our psychology and confer a significant burden on psycho-social functioning and everyday life, which should be addressed within a structure of planned health care. Although some educational and management programmes exist which have shown good success in supporting those with food allergy (in particular), research in the field shows that the addition of a psychological component (such as using the principles of cognitive behaviour therapy and/or mindfulness) improves efficacy and provides a longer term impact. Such programmes are particularly effective in cases where high levels of anxiety or avoidance are present. It is important to also address parental anxiety and to provide clear and personalised information. Where uncertainty is present, this should be acknowledged and discussed. Parents can transmit their anxiety to their child, and just as children can pick up on parental anxiety, they can also respond to a parent’s ability to stay calm in stressful situations. Allaying parental anxiety reduces the child’s anxiety and creates a positive feedback loop, which ultimately benefits both the child and parent.


Coming next : why is food allergy and food intolerance becoming more prevalent ?

Do you have a food allergy? Do you want to be part of a worldwide study on reactions in the community?