Quick read · 5 min
Eating through peak hayfever season
What to add, what to swap, and what the evidence actually says
In short
What to add, what to swap, and what the evidence actually says
Food won't cure hayfever. But certain foods can add or remove load on a system already working hard, and a handful of dietary changes during peak season are well-supported by the evidence. Others — including some of the most popular folk remedies — are not.
This is what the research actually says.
What to add (modest but real benefit)
Omega-3 fatty acids
The mechanistic case is solid: omega-3s shift inflammatory signalling away from the pro-allergic Th2 pathway that drives hayfever. Observational studies find people with higher omega-3 intake report fewer rhinitis symptoms. The clinical-trial evidence is more modest — effects are real but not transformative.
Practical version: oily fish (salmon, mackerel, sardines, herring) two to three times a week, or a high-quality fish oil supplement if you don't eat fish.
Quercetin-rich foods
Quercetin is a flavonoid that stabilises mast cells in laboratory studies, reducing their tendency to release histamine. Human trials are limited but consistent in direction.
Food sources: red onions, capers, apples (cooked if you're oral allergy syndrome sensitive), berries, kale, dark leafy greens. The dose in food is much lower than supplement trials use, but it's a sensible addition.
Polyphenol-rich foods generally
Green tea, dark chocolate (the high-cocoa kind), berries, herbs and spices — all rich in compounds that modulate inflammatory pathways. Effect sizes are individually small but additive.
What to swap (if it applies to you)
Raw fruit and nuts → cooked, if you have OAS
Pollen-food allergy syndrome affects around 1 in 11 hayfever sufferers. The proteins involved are heat-labile — cooking denatures them.
- Birch sufferers: raw apple, pear, cherry, peach, plum, hazelnut, almond, carrot, celery → cooked or peeled fine.
- Grass sufferers: raw melon, tomato, kiwi, peanut, orange → cooked, peeled, or canned typically fine.
- Mugwort sufferers: raw celery, carrot, fennel, parsley, coriander, sunflower seeds → cook to denature.
If raw fruit suddenly feels tingly or scratchy through peak season, this is what's happening — not a new food allergy.
High-histamine foods if you're sensitive
Some people find their symptoms worsen with foods that are themselves high in histamine or that trigger histamine release. The evidence here is mixed, but if you notice a pattern, the usual suspects are:
- Aged cheeses, cured meats, fermented foods (kimchi, sauerkraut, kombucha)
- Tomatoes, spinach, aubergine in large quantities
- Wine and beer (alcohol both contains histamine and triggers its release)
This isn't a universal rule — most people don't need to avoid these. But if a bad-reaction day correlates with one of them, it's worth tracking.
What to skip (popular myths)
Local honey
This one is loved, and it doesn't work. Bees collect insect-pollinated flower pollen, which is sticky, heavy, and biologically different from the wind-pollinated grass, tree, and weed pollen that causes hayfever. The proteins are unrelated. A 2011 Finnish pilot study sometimes cited used honey deliberately spiked with concentrated birch pollen at doses you'd never get from a jar — closer to clinical immunotherapy than a kitchen remedy. The 2020 systematic review found no credible evidence for standard honey.
If you enjoy honey, eat it. Just not as treatment.
Bee pollen supplements
Same problem, with a small added risk: people sensitive to grass and weed pollen can have allergic reactions to bee pollen supplements. Skip.
Megadose vitamin C
The evidence for vitamin C in hayfever is weak and inconsistent. Normal dietary intake (citrus, peppers, berries) is sensible nutrition; high-dose supplements aren't worth the spend.
Practical structure for the season
- Breakfast: cooked fruit (stewed apple, berries) on porridge, eggs, salmon on toast. Skip raw apple/pear/hazelnut if birch-sensitive.
- Lunch: leafy greens, cooked vegetables, oily fish or quality protein. Quercetin via red onion, capers, herbs.
- Dinner: vary it. Two to three oily-fish meals a week across the season.
- Drinks: green tea, water. Reduce alcohol on bad reaction days at minimum, ideally across peak.
- Hydration: keep it up. Dehydration thickens nasal mucus and slows clearance.
Diet won't carry the season on its own — your nasal spray, antihistamine, and bedroom setup do the heavy lifting. But the food piece is a quiet supporting layer, and the OAS swaps in particular can take a small daily irritation off the table entirely.
The evidence
What the research actually says
Each answer below is drawn from a graded research review. Confidence reflects the strength of the underlying evidence, not how confident we feel about it.
Does adherence to a Mediterranean diet reduce allergic rhinitis symptom severity compared to a standard Western diet?
Observational evidence, primarily from cross-sectional studies in children, suggests that high adherence to a Mediterranean diet (MedDiet) is associated with reduced prevalence and risk of allergic rhinitis (AR) symptoms compared to lower adherence or pro-inflammatory dietary patterns. Key studies report odds ratios of 0.34–0.49 for AR in high versus average/low MedDiet adherence groups, indicating a potential 50–66% risk reduction. However, no randomized controlled trials have directly compared MedDiet to a standard Western diet using validated symptom severity scales (e.g., TNSS, RQLQ), meaning the evidence addresses disease prevalence rather than symptom severity per se.
How it works
The MedDiet's high content of fruits, vegetables, nuts, olive oil, and fish is hypothesized to reduce AR symptom burden primarily through antioxidant activity that attenuates oxidative stress in airway tissues, and through anti-inflammatory effects (e.g., omega-3 fatty acids, polyphenols) that may suppress Th2-skewed immune responses; conversely, Western diet components such as margarine and trans-fats are thought to promote pro-inflammatory signaling that exacerbates atopic responses. Gut microbiome modulation and specific pathway activation (e.g., Nrf2, short-chain fatty acid production) are proposed but remain unquantified in the available AR literature.
Confidence: low
Does consuming local honey reduce pollen sensitisation or hayfever symptom severity?
Current evidence does not support local honey as an effective treatment for reducing pollen sensitisation or hayfever symptom severity. While a small number of RCTs (including one Malaysian trial and a birch pollen honey pilot study) suggest modest short-term symptomatic improvement when honey is used adjunctively with antihistamines, these findings are inconsistent, methodologically limited, and do not extend to demonstrating immunological desensitisation. A 2020 systematic review found no credible evidence supporting honey for allergic rhinitis, and no peer-reviewed RCTs have specifically tested locally-sourced honey.
How it works
The proposed mechanism mirrors oral allergen immunotherapy, whereby trace pollen in honey induces incremental immune tolerance and suppresses IgE-mediated hypersensitivity; however, this is biologically implausible for most hayfever sufferers because local honey contains primarily entomophilous (insect-borne) flower pollen, not the anemophilous (wind-borne) grass, tree, and weed pollens responsible for the majority of allergic rhinitis cases.
Confidence: low
Which foods cross-react with grass pollen allergens?
Grass pollen allergens most commonly cross-react with foods in the melon family (cantaloupe, watermelon, honeydew), tomatoes, potatoes, oranges, peaches, celery, peanuts, and kiwi, producing pollen-food allergy syndrome (PFAS) or oral allergy syndrome (OAS) in sensitized individuals. Reactions are typically mild and localized to the oropharynx due to heat-labile proteins denatured by cooking or digestion, though LTP-mediated reactions (e.g., peaches) can occasionally trigger systemic anaphylaxis. An estimated 20–50% of grass pollen-allergic individuals report oral symptoms upon ingesting implicated raw foods, though confirmed clinical reactivity rates are lower.
How it works
Cross-reactivity is driven primarily by structural homology between grass pollen pan-allergens—particularly profilins (e.g., Phl p 12 from timothy grass, sharing >70% sequence identity with food profilins in melons, tomatoes, and peanuts)—and homologous proteins in plant foods, triggering IgE-mediated mucosal responses following prior inhalational sensitization. Non-specific lipid transfer proteins (nsLTPs, e.g., Phl p 14) represent a secondary but clinically significant mechanism, as their thermostability and digestion resistance underlie more severe reactions associated with fruits such as peaches.
Confidence: moderate
Which foods cross-react with birch pollen allergens?
Birch pollen allergens, particularly Bet v 1 (a PR-10 pathogenesis-related protein), cross-react with homologous proteins in a wide range of foods including Rosaceae fruits (apple, pear, peach, cherry), Apiaceae vegetables (carrot, celery), nuts (hazelnut, almond), and legumes (soy, peanut), causing pollen-food allergy syndrome (PFAS)/oral allergy syndrome (OAS) in an estimated 70% of birch-sensitized individuals. Secondary cross-reactivity via Bet v 2 (profilin) occurs in approximately 10-15% of birch-allergic patients and broadens the implicated food spectrum. Reactions are typically mild and localized to the oropharynx due to the heat-labile nature of these proteins, which are degraded by cooking and gastric digestion.
How it works
IgE antibodies raised against Bet v 1 recognize structurally homologous PR-10 proteins in foods (e.g., Mal d 1 in apple, Cor a 1 in hazelnut, Gly m 4 in soy, Ara h 8 in peanut) due to high amino acid sequence identity (>40-60%), triggering mast cell degranulation at oral mucosal surfaces. Cross-reactive T-cell responses to these food homologues, as demonstrated for Bet v 1 and Mal d 1, further amplify and sustain the allergic sensitization.
Confidence: high
Does quercetin inhibit mast cell degranulation?
Quercetin consistently inhibits mast cell degranulation across multiple in vitro and preclinical models, suppressing release of histamine, β-hexosaminidase, PGD₂, leukotrienes, and pro-inflammatory cytokines. Multiple mechanistic pathways have been identified, with effective concentrations demonstrated at 100 µM in human mast cell lines, showing comparable but slightly inferior performance to cromolyn in direct comparisons. A 2025 systematic review and meta-analysis of preclinical studies corroborates these multi-target anti-allergic effects, though direct clinical evidence in allergic rhinitis patients is lacking.
How it works
Quercetin acts as an agonist at inhibitory CD300 family receptors (CLM-1/CD300f) on mast cells, triggering SHP-1 phosphorylation that suppresses downstream MyD88/IKK/NF-κB signaling and PI3K/AKT/Rac1/Cdc42 pathways, thereby reducing calcium influx, F-actin cytoskeletal remodeling, and granule exocytosis; additional mechanisms include downregulation of FcεRI surface expression and heme oxygenase-1 induction.
Confidence: moderate
Do high-fibre diets reduce allergic disease?
High-fibre diets show promising but inconsistent evidence for reducing allergic disease, with the strongest signals seen for atopic dermatitis and house dust mite sensitisation in observational human studies and mechanistically rich animal models. Evidence for allergic rhinitis and asthma is more mixed: general dietary fibre and SCFA production appear protective in preclinical models, but specific fibres such as inulin have been shown to exacerbate type 2 airway inflammation via ILC2 activation and eosinophilia. No large-scale RCTs specifically targeting allergic rhinitis outcomes with high-fibre dietary interventions have been identified.
How it works
Fermentable dietary fibres are metabolised by gut microbiota into short-chain fatty acids (SCFAs—acetate, propionate, butyrate), which modulate immune responses via the gut-lung and gut-skin axes by suppressing IgE-mediated mast cell activation, promoting regulatory T cell activity, strengthening epithelial barrier integrity, and shaping the lung's immunological environment. However, certain fibres (e.g., inulin) can paradoxically drive Bacteroidetes-mediated bile acid production and ILC2 activation, promoting pro-allergic type 2 inflammation in a context-dependent manner.
Confidence: low
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This article is general information about hayfever, not medical advice. It should not replace guidance from your GP, pharmacist or allergy specialist — particularly if you are pregnant, treating a child, or managing asthma alongside hayfever. Read our medical disclaimer.
