A food allergy is where the immune system mistakes something that has been eaten for something harmful. This leads to food allergy symptoms each time this food is consumed. For parents who have food allergies themselves, or children with a sibling with a food allergy it is common to worry a child will inherit the food allergy too.

Several factors contribute to a child developing a food allergy. An important one is a genetic predisposition to atopy (allergic conditions like eczema, asthma, food allergy and/or hayfever). Environmental factors may also influence allergy risk. Keep reading to learn more about the risk of food allergies in children.  

This blog will cover the following;

• The rates of food allergy in children in the UK

• Is it possible for children to inherit food allergy through genetics?

• Risk factors for children developing a food allergy

• Can you prevent food allergies in children?

How common are food allergies in children? 

Affecting an estimated 3-6% of children under 2 years old, food allergies are fairly common in young children in the UK.  Over the past two decades, there has, however,  been an increase in the number of children diagnosed with food allergies in the UK. Not all food allergies are forever. Many children will outgrow their food allergies by the time they are 5 years old, with figures suggesting the prevalence of food allergies in the whole paediatric population (0-16 years) at 1-2%.

Some of the most common food allergens are cow’s milk, eggs, peanuts, fish, and tree nuts (such as walnuts, almonds, and hazelnuts). Over 90% of food allergies diagnosed in children are to the top 9 food allergens listed below:

• Milk

• Egg

• Soya

• Peanut

• Tree nuts

• Sesame

• Wheat

• Fish

• Shellfish

can children inherit food allergy?

Any parent with a food allergy themselves is keen to understand how to prevent their child from developing the same or other food allergies.  Whilst children don’t directly inherit specific allergies from their parents, there is a known genetic susceptibility to developing allergies. Children are more likely to have a food allergy if there is a family history of atopy, or if they already have an atopic disease.  The risk is known to increase further if both parents have atopic conditions themselves.

Atopy is the genetic tendency to develop allergic diseases including; hay fever, asthma, eczema, and food allergy. Atopy is associated with heightened immune responses.

The link between food allergies and eczema is the strongest. Evidence shows that babies who have eczema in their first three to four months of life, and/or those with severe eczema are more likely to develop food allergies. This is because whilst ingesting (eating) food allergens helps to tell the immune system that a food is safe, exposure to food allergens via the skin before foods are eaten (and in the case of eczema a compromised skin barrier) is now understood to contribute to the immune system sensitising to this food protein or going on to develop a full immune response (food allergy).

Susceptibility to food allergy may also be influenced by environmental factors. The use of antibiotics, birth, feeding methods, dietary habits, and urban versus farm living all affect the microbiota composition. Research is ongoing exploring the link between these factors, the gut microbiome and food allergy risk.

 

can you prevent food allergies in children?

While possible, it is not guaranteed that we can prevent food allergies in children. That said, there have been significant advances in our understanding of how we can support allergy prevention in children over the last 5-10 years. This is thanks to high-quality scientific studies completed here in the UK. Some important guidance from the evidence includes;

Don’t delay the introduction of allergenic foods during weaning

It is now widely recommended to avoid delaying the introduction of common food allergens during weaning (introduction of solids). Delaying the introduction of allergens may increase the risk of your child developing an allergy to those foods.  Clear advice is to now actively introduce these foods, in a  stepwise and safe way to your baby once they commence solids. Research advises doing this before 12 months of age but has also specifically identified a window of opportunity for the introduction of specific allergens like peanut and egg between 4-6 months of age. Babies at higher risk of food allergy, which are those with a food allergy (like milk allergy) already, and/or those with eczema are particularly likely to benefit from the earlier introduction to allergenic foods. If this is the case for your baby, consider discussing in more detail with a health professional and seeking support with weaning.

You can find more information about introducing allergens during weaning here:

Pregnant and breastfeeding mothers should not exclude food allergens from their own diet 

There is currently no evidence that avoiding allergenic foods like peanuts during pregnancy or breastfeeding impacts food allergy development in babies. It is recommended that women continue to include these foods within their diet unless they require exclusion due to maternal allergy or dietary choices.

There is some emerging evidence that maternal consumption of peanuts during breastfeeding, alongside early peanut introduction as a baby during weaning may support peanut allergy prevention.

Milk Allergy - Consider careful management of formula milk introduction alongside breastfeeding 

There are some scientific studies that have identified that giving babies top-up formula milk feeds in the early days of life whilst establishing breastfeeding, which are later stopped, may increase the risk of milk allergy. If you are planning to breastfeed your baby, it would be recommended to seek additional breastfeeding support after birth where possible.

Further resources

• FSA. Providing information on food allergy and intolerance.

• Allergy UK. Providing advice, information, and a helpline for people living with allergies.

• The anaphylaxis campaign. Support for people living with severe food allergies.

 

References

Halken S, Muraro A, de Silva D, Khaleva E, Angier E, Arasi S, Arshad H, Bahnson HT, Beyer K, Boyle R, du Toit G, Ebisawa M, Eigenmann P, Grimshaw K, Hoest A, Jones C, Lack G, Nadeau K, O'Mahony L, Szajewska H, Venter C, Verhasselt V, Wong GWK, Roberts G; European Academy of Allergy and Clinical Immunology Food Allergy and Anaphylaxis Guidelines Group. EAACI guideline: Preventing the development of food allergy in infants and young children (2020 update). Pediatr Allergy Immunol. 2021 Jul;32(5):843-858. doi: 10.1111/pai.13496. Epub 2021 Mar 29. PMID: 33710678.

Abrams EM, Shaker MS, Chan ES, Brough HA, Greenhawt M. Prevention of food allergy in infancy: the role of maternal interventions and exposures during pregnancy and lactation. Lancet Child Adolesc Health. 2023 May;7(5):358-366. doi: 10.1016/S2352-4642(22)00349-2. Epub 2023 Mar 2. PMID: 36871575.

Prescott SL, Pawankar R, Allen KJ, Campbell DE, Sinn JKh, Fiocchi A, Ebisawa M, Sampson HA, Beyer K, Lee BW. A global survey of changing patterns of food allergy burden in children. World Allergy Organ J. 2013 Dec 4;6(1):21. doi: 10.1186/1939-4551-6-21. PMID: 24304599; PMCID: PMC3879010

Contributions

This blog was written in collaboration between Lucy Upton and Emilia Fish.