Question: Last summer, I spent five months laid low by hay fever that did not get much better with medication. I’m also afflicted by gut issues that appear to be triggered by wheat and dairy, which seem to make my hay fever worse. Can food intolerances add to hay fever?
Answer: Hay fever, or allergic rhinitis, affects about 40% of people. And scientists expect rates to worsen as a result of climate change. A 2022 study published in Nature Communications predicted pollen seasons could start up to 40 days earlier, run for longer and cause more people to develop seasonal allergies.
Understanding whether diet can affect hay fever symptoms is therefore highly relevant. And with spring around the corner, it’s worth asking whether dietary changes can ease seasonal allergy symptoms.
Allergic rhinitis refers to inflammation of the inside of the nose by an allergen, whether from mould, dust mites, cats, dogs or different types of pollens. It typically causes cold-like symptoms such as sneezing, itchiness and a blocked or runny nose. This can be particularly confusing in the Covid era, given the shared symptoms.
Whether certain foods can worsen hay fever is not clear. However, we know sensitivities to certain foods can cause rhinitis or the nasal-type symptoms that are similar to hay fever. If you already have hay fever and are allergic to certain foods, it’s possible your nasal symptoms will worsen. Some food allergies – wheat and dairy are good examples – can cause a stuffy or runny nose and sneezing. These symptoms typically do not occur in isolation with a food allergy, often appearing alongside other symptoms such as hives or a skin rash, nausea, stomach cramps and other gastrointestinal symptoms.
Nasal symptoms are not uncommon with food allergies. In a double-blind clinical trial involving 185 children with food allergies, 39% experienced symptoms in their eyes and upper respiratory tract in addition to typical food-allergy symptoms.
Wheat allergies are more common in children and typically are outgrown by adulthood. However, in adults with cross-sensitivity to grass pollen, wheat allergies can develop that can include nasal symptoms alongside gastrointestinal symptoms and potentially rashes.
Indeed, 5-8% of patients with a pollen allergy will subsequently develop a food allergy, so-called pollen-food allergy syndrome. So patients with pollen allergies may have allergy-related symptoms after eating certain fruits, vegetables, nuts or spices that contain proteins similar to pollen proteins.
The link between grass pollen allergies and subsequent allergies to wheat fits that pattern. For example, a 2018 study in the International Archives of Allergy and Immunology found among children aged 5-17 with a diagnosed grass pollen allergy, 60% were also sensitised to wheat. That is, although they did not necessarily experience physical symptoms, their body did have an immunological allergy response to wheat.
Bear in mind the very classification of being “asymptomatic” is being challenged these days, because though people sensitised to wheat may not display typical symptoms of a food allergy, neuroscientists contend that does not exclude the hypersensitivity causing other atypical symptoms.
What’s more, a clinical trial published in 2016 in the Journal of Microscopy and Ultrastructure found among 100 patients aged 10-60 with diagnosed allergic rhinitis, 63% were sensitised to common food allergens. Interestingly, the highest rates of food allergy in patients with allergic rhinitis were among women aged 21-40.
This all adds up to good grounds for suspecting certain foods may worsen your rhinitis. Follow up with your GP or an allergy specialist for further testing to determine if an undiagnosed food allergy or sensitivity worsens your symptoms.