During a recent interview on Radio 100.7, Dr Annette Kuehn and Dr Christiane Hilger, allergy specialists from the Molecular & Translational Allergology Group at the Department of Infection & Immunity (LIH), discussed the growing prevalence of allergies and the factors that may be driving this trend.
The two experts highlighted that food allergies are becoming increasingly common, with milk, eggs, wheat, soy, meat, and nuts among the most frequent allergen sources. A population-based study carried out by their research group, in collaboration with Drs Ruiz & Fagherazzi from the Department of Precision Health, revealed that more than 40% of adults in Luxembourg reported a physician-diagnosed allergy — a figure that aligns with the European average.
Dr Hilger outlined three major allergy waves observed over the last century: hay fever, paediatric asthma, and food allergies. She pointed to several contributing factors, including elevated hygiene standards, shifts in agricultural practices, climate change, air pollution, and the growing consumption of processed foods.
The specialists also underlined the role of early environmental exposure. Children raised on farms tend to develop fewer allergies compared to those growing up in urban settings. Dr Kuehn emphasised that diagnosing allergies requires careful monitoring of symptoms — their nature, frequency, and the context in which they appear. She noted that experiencing multiple symptoms simultaneously after eating may indicate anaphylaxis, a severe reaction requiring urgent medical care.
Dr Hilger drew a distinction between respiratory allergies — characterised by itchiness, sneezing, eye irritation, and breathing difficulties — and food allergies, which typically manifest as oral tingling, stomach pain, diarrhoea, and skin reactions. Both types can progress to asthma or anaphylaxis, and anyone experiencing moderate to severe symptoms should consult a healthcare professional.
The second part of the interview explored the potential link between processed foods and the rise in food allergies. Dr Hilger acknowledged this as a widely discussed hypothesis, while stressing that further research is needed to fully understand the impact of food additives and other substances. The experts called for thorough testing of all ingredients — including those found in cosmetics — to assess their effect on the epithelial barrier. This barrier, present in the skin, gut, and lungs, acts as a first line of defence against external threats. When disrupted, it allows allergens and other molecules to enter the body more easily, potentially triggering immune responses and chronic inflammatory conditions.
Dr Kuehn also clarified the difference between intolerances and allergies: intolerances do not involve the immune system and are often linked to an enzymatic deficiency, whereas allergies trigger immune system changes that can, in some cases, diminish over time as the immune system matures.
The interview concluded with a call for greater public awareness around allergies, prompt medical consultation when symptoms arise, and continued research into the long-term effects of substances present in food and everyday products.
The full interview is available online in Luxembourgish and German.
