Streaming eyes, a bunged-up nose and constant sneezes – for Britain’s 16 million hay fever sufferers, the start of the season – with pollen counts today predicted to be very high – promises weeks, if not months, of misery. But could simple dietary changes help reduce your suffering?
A growing body of research suggests that what we eat – and drink – really can make a difference.
For instance, focussing on eating foods that promote a healthy gut microbiome, the community of microbes that live in the gut, has been shown to reduce symptoms, according to a review of studies published recently in the journal Current Research in Microbial Sciences.
The researchers, at the Children’s Hospital of Chongqing Medical University in China, analysed the data from 18 studies and concluded that high-fibre foods – which ‘good’ gut bacteria feed off – were key.
This follows other studies that found that alcohol and certain types of meat can exacerbate hay fever symptoms. Red wine, in particular, may be a problem – so is it the season to switch to white?
Hay fever occurs when the immune system mistakes pollen for a threat, setting off an immune response.
Immune cells called mast cells release the chemical histamine – this increases mucus production (to help trap and remove the pollen) and dilates blood vessels; hence the runny nose but bunged-up feeling, as well as sneezing and streaming eyes.
But scientists now have a new understanding of how that immune response can be altered.
‘We know that around 70 per cent of the immune system is located in the gut’ says Megan Rossi from King’s College London
‘We know that around 70 per cent of the immune system is located in the gut, and what we feed our gut microbes can influence how that immune system behaves,’ says Megan Rossi, a research fellow in gut health at King’s College London and founder of The Gut Health Doctor.
That’s because, when fed their favourite fibre-rich foods, beneficial gut bugs flourish and produce compounds called short-chain fatty acids that ‘help regulate key aspects of immune function’, she explains. And it’s thought these acids may be key to cutting hay fever symptoms.
This tallies with the finding of the recent review, which found that those (in this case children but the same is thought to apply to adults) with allergies such as hay fever were consistently shown to have differences in the type of bacteria dominating their gut, compared with healthy children.
Specifically, those with allergies tended to have lower levels of Lactobacillus and Bacteroides, which are thought to help train the immune system to tell the difference between a genuine threat, such as a virus, and something harmless, such as pollen.
The review found the children with hay fever also had lower levels of short-chain fatty acids.
‘So in simple terms, a well-nourished gut microbiome may help make the immune system less trigger-happy,’ says Megan Rossi.
And that means fewer hay fever symptoms.
She says she sees this in patients who are struggling with various allergies, not just hay fever – when they focus on eating more fibre and a diverse range of plant-based foods, ‘I see improvements in some patients,’ she says.
Sarah Berry, a professor of nutritional sciences at King’s College London, agrees that ‘it is plausible that diet may help alleviate hay fever symptoms and that this may in part be mediated by the microbiome’.
Sarah Berry, professor of nutritional sciences, says that gut microbiome plays an integral role in training the immune system
‘We know that the gut microbiome plays an integral role in “training” the immune system, which is, of course, important in allergies,’ she told the Mail.
And there may be other ways – beyond diet – to do that.
Taking probiotic supplements, which boost numbers of friendly bacteria, can help reduce hay fever symptoms, according to the 2025 review – and other studies support this.
For example, in a 2017 study hay fever sufferers were given either capsules containing three strains of bacteria found in a healthy gut (Lactobacillus gasseri, Bifidobacterium bifidum and Bifidobacterium longum) or a dummy pill, during pollen season. After eight weeks, those taking the probiotics reported a 68 per cent improvement in symptoms, compared with 19 per cent in the placebo group, reported the American Journal of Clinical Nutrition.
And an Australian study in 2022, published in Frontiers in Nutrition, found that adults who took a probiotic formula for ten to 12 weeks had significantly reduced symptoms such as runny noses and itchy eyes than those taking a placebo.
But some experts are not convinced.
Professor Glenis Scadding, a consultant physician in allergy and rhinology at the Royal National ENT Hospital in London, says that the evidence for probiotics (also found in fermented foods such as kefir and sauerkraut), and prebiotics (fibre-rich foods and supplements that feed the good bacteria in the gut) is mixed with ‘both positive and negative outcomes’.
In some trials, she points out, they simply did not work, while some people experienced mild digestive side-effects such as bloating and diarrhoea.
Some experts say that evidence for probiotics and prebiotics is mixed with ‘both positive and negative outcomes
However, when it comes to alcohol the links are more certain.
For instance, younger women who drank more than 14 alcoholic drinks a week were more likely to develop a blocked nose caused by a range of allergies including pollen and house dust mites, according to a Danish study published in 2008, which monitored nearly 6,000 participants for almost eight years.
That may be because some forms of alcohol – particularly red wine – contain histamine, the same chemical the body releases during an allergic reaction.
Red wine can contain up to 3,800mcg of histamine per litre, compared with as little as 3mcg in some white wines.
‘Alcohol can certainly augment hay fever symptoms via its histamine and sulphite content [preservatives that can irritate the airways and trigger sneezing and congestion] and its dehydrating effects [which dry out the lining of the nose, making it more sensitive to pollen] – so avoidance is sensible,’ says Professor Scadding.
And studies have also found cutting back on processed meat such as bacon and sausages can reduce inflammation linked to an overactive immune system – which can make allergies more likely or worsen symptoms.
A study of more than 21,000 people in Nature Microbiology last year [2025] found that a meat-heavy diet was associated with having more of the type of gut bacteria linked to inflammation and lower levels of beneficial short-chain fatty acids.
‘It is well-established that following a diet rich in plants is associated with a healthy immune system and lower levels of inflammation, both of which are important aspects of allergies,’ says Professor Berry.
But diet alone is not going to cure hay fever, she adds.
‘For some people, dietary changes might reduce symptoms enough that they can get on with their lives. But it wouldn’t be a cure. It is notoriously challenging to cure allergies.’
That’s partly because the severity of the symptoms of hay fever depends on several factors.
Earlier, longer and sometimes more intense pollen seasons are driving symptoms.
What’s more, urban planting may also play a role. Birch trees are often favoured in town centres in the UK and around new developments as they grow quickly – but they release a lot of pollen and a 2025 review in the Journal of Allergy and Clinical Immunology: In Practice warned that wind-pollinated trees and grasses, including birch, can increase allergy risk in built-up areas.
Air pollution too is thought to play a part by attaching to pollen and carrying it deeper into the lungs.
Anne Biggs, deputy head of clinical services at the charity Allergy UK, says standard treatments such as non-sedating antihistamines, steroid nasal sprays and eye drops remain the most effective options for most people.
She also recommends wearing wraparound sunglasses, applying barrier balm around the nostrils and showering after being outdoors to reduce the amount of pollen reaching the nose and eyes.
For severe cases, Allergy UK recommends immunotherapy – also called desensitisation therapy – in which patients are given gradually increasing doses of pollen extract over two to three years to retrain the immune system, so it no longer overreacts.
‘We would advise a healthy diet to complement but not replace standard hay fever management,’ says Anne Biggs.
