In February 2023, 13-year-old Hannah Jacobs died from a severe allergic reaction after drinking a hot chocolate from Costa Coffee. Hannah suffered from allergies to dairy, fish and eggs, and her mother had asked for soy milk, but the hot chocolate contained cows’ milk. In July 2016, 15-year-old Natasha Ednan-Laperouse died on a flight after eating a Pret a Manger baguette she had bought at Heathrow. She had a severe allergic reaction to sesame, which had been baked into the bread but wasn’t listed on the ingredients label.
These types of fatal events linked to food allergies seem to be occurring more frequently. They appear in headlines and have driven a movement to make planes, schools and other restricted environments “nut-free”. But are food allergies really on the rise, or is our coverage of them merely increasing?
A recent study in the Lancet Public Health journal provides answers. Led by Paul Turner of Imperial College London, it found that food allergies had doubled between 2008 and 2018. Most of these affect children. By reviewing data from GP surgeries in England, the researchers found that across all age groups, food allergies had increased from 0.4% to 1.1% of the population.
Since 2014, the rise has been less notable, which is possibly due to advice from NHS and medical staff to introduce potential food allergens into the diet of children before the age of 12 months. Early introduction seems to substantially reduce the risk of developing allergies to foods such as peanut and egg. But we can’t see what has happened more recently: the Lancet Public Health analysis couldn’t go beyond 2020 because the Covid pandemic affected GP visits and data.
This rise in allergies isn’t unique to England. They are increasing around the world. What explains this? Experts have put forward a number of hypotheses, all of which need testing. A food allergy is caused by the immune system overreacting to certain foods, releasing chemicals that cause symptoms such as itchy skin and hives, a swollen face, eyes, or lips, breathing difficulties and even cardiac arrest. In short, food substances are causing the immune system to malfunction. As the medical anthropologist Theresa MacPhail put it: “If your immune response gets triggered by the wrong things, it will kill you by trying to protect you.”
One possible explanation is the rise of the “western” diet, which is high in ultra-processed foods. A 2022 study of nearly 3,000 children and 4,256 adults in the US suggested that consuming ultra-processed foods was associated with allergy symptoms in children and adolescents. Perhaps the full detrimental impacts of ultra-processed foods are only now being recognised, as data is collected and analysed. There are close links between the gut microbiome and the immune system; similar concerns have been raised about their possible link to digestive-tract cancers in young people.
Another theory is that those who develop allergies are deficient in vitamin D, the vitamin our body produces when exposed to sunlight. Surveys have shown that children are spending an increasing amount of time indoors on screens instead of outdoors playing. This isn’t just a post-pandemic trend: it has been happening for more than a decade, alongside the growing use of tablets, games consoles and phones.
Other explanations have included the widespread use of antibiotics in young children (for ear infections or other ailments), which affect the digestive tract, rising air pollution and early exposure to skin infections. The health community will continue to look to scientists such as Turner, who is also a paediatric allergy consultant, to test the various hypotheses on why these allergies are developing and what can be done to prevent them in children.
We need to support those who have severe allergies by raising awareness in the food and drinks business to ensure proper labelling and stop cross-contamination; by moving towards “allergen-free” environments, including on planes and in schools; and by ensuring people have wide access to EpiPens and other treatments to prevent life-threatening incidents. Turner led another analysis that found many patients are not being prescribed these pens even after they have suffered from a severe allergic reaction.
We are only beginning to understand the rise of food allergies. It’s a subject that is ripe for more research, because it can literally be a case of life and death.
Prof Devi Sridhar is chair of global public health at the University of Edinburgh
