Hay Fever Season Intensifies as New Study Suggests Dietary Choices May Offer Relief

As Britain braces for another grueling hay fever season, with pollen counts forecasted to reach "very high" levels, the 16 million individuals affected by this seasonal torment are facing a prolonged battle against relentless symptoms. From streaming eyes and blocked nasal passages to incessant sneezing, the condition has become a defining challenge for many. Yet emerging research suggests that dietary choices may hold unexpected power in mitigating these distressing effects. A recent review published in *Current Research in Microbial Sciences* highlights how nutrition—specifically the foods we consume—can influence immune responses and alleviate hay fever symptoms. Researchers at China's Children's Hospital of Chongqing Medical University analyzed data from 18 studies, revealing a compelling link between high-fiber diets and reduced symptom severity. This aligns with broader findings that certain foods, such as alcohol and specific meats, may worsen the condition, while others, like red wine, could exacerbate it further.

The immune system's reaction to pollen is a complex interplay of biological signals. When allergens enter the body, immune cells known as mast cells release histamine, triggering mucus production, blood vessel dilation, and the telltale symptoms of hay fever. However, recent scientific insights reveal that this immune response may be modifiable through dietary interventions. Megan Rossi, a research fellow in gut health at King's College London and founder of *The Gut Health Doctor*, emphasizes that 70% of the immune system resides in the gut. "What we feed our gut microbes can influence how that immune system behaves," she explains. Beneficial gut bacteria thrive on fiber-rich foods, producing short-chain fatty acids that regulate immune function. These compounds may play a pivotal role in dampening the overzealous immune reactions that characterize allergies like hay fever.

Studies have consistently shown that individuals with allergies, including hay fever, exhibit distinct gut microbiome profiles compared to healthy counterparts. Children with hay fever, for instance, often display lower levels of Lactobacillus and Bacteroides—microbes believed to help the immune system distinguish between harmless substances like pollen and genuine threats such as viruses. Concurrently, these children tend to have reduced short-chain fatty acid levels, a finding that underscores the potential of a well-nourished gut microbiome in tempering immune hyperactivity. "A balanced gut microbiome may help the immune system become less reactive," Rossi notes, adding that she has observed improvements in patients with allergies who adopt diets rich in fiber and diverse plant-based foods.

Professor Sarah Berry, a nutritional sciences expert at King's College London, corroborates this perspective. "The gut microbiome plays an integral role in training the immune system, which is crucial in managing allergies," she states. Beyond diet, probiotic supplementation has also shown promise. A 2025 review suggests that probiotics can reduce hay fever symptoms, a claim supported by a 2017 study. In this trial, participants with hay fever were given capsules containing three strains of beneficial gut bacteria—Lactobacillus gasseri, Bifidobacterium bifidum, and Bifidobacterium longum—or a placebo during pollen season. After eight weeks, those taking the probiotics reported a 68% improvement in symptoms, compared to just 19% in the placebo group, according to the *American Journal of Clinical Nutrition*.

These findings underscore a growing consensus among experts that dietary and microbiome-focused strategies may offer viable tools for managing hay fever. While no single solution exists, the interplay between nutrition, gut health, and immune regulation presents a promising avenue for reducing the burden of this seasonal affliction. As researchers continue to explore these connections, public health advisories increasingly emphasize the importance of informed dietary choices in safeguarding well-being during allergy season.

A 2022 Australian study published in *Frontiers in Nutrition* revealed that adults who took a probiotic formula for ten to twelve weeks experienced significantly fewer symptoms like runny noses and itchy eyes compared to those on a placebo. The research, which involved hundreds of participants, suggested that certain probiotic strains might help modulate the immune system's response to allergens. However, the findings have sparked debate among experts.

Professor Glenis Scadding, a consultant physician in allergy and rhinology at London's Royal National ENT Hospital, acknowledges the potential but cautions that the evidence for probiotics and prebiotics is "mixed." She notes that while some trials show benefits, others have found no effect. "In some cases, probiotics simply didn't work," she says. "And for some people, they caused mild digestive issues like bloating or diarrhea." Scadding emphasizes that the gut microbiome's complexity makes it challenging to predict how individuals will respond to these supplements.

When it comes to alcohol, the link to allergy symptoms is more definitive. A 2008 Danish study tracked nearly 6,000 people over eight years and found that younger women who consumed more than 14 alcoholic drinks weekly were more likely to develop nasal blockage linked to allergies like pollen and house dust mite reactions. Red wine, in particular, stands out due to its high histamine content—up to 3,800mcg per litre, compared to just 3mcg in some white wines. Histamine is a chemical the body releases during allergic reactions, and alcohol's sulphite preservatives can further irritate airways.

"Alcohol definitely worsens hay fever symptoms," Scadding explains. "The histamine and sulphites in drinks, combined with alcohol's dehydrating effects, dry out nasal linings and make them more sensitive to pollen. Avoidance is sensible." Other lifestyle factors also matter. A 2025 study in *Nature Microbiology* found that diets heavy in processed meats like bacon and sausages correlate with higher levels of gut bacteria linked to inflammation and lower levels of beneficial short-chain fatty acids.

Professor Berry, a nutrition expert, highlights the importance of plant-based diets. "A diet rich in plants supports a healthy immune system and reduces inflammation, both of which are critical for managing allergies," she says. However, she stresses that diet alone cannot cure hay fever. "For some, changes might ease symptoms enough to improve quality of life, but it's not a cure. Allergies are notoriously hard to eliminate."

The severity of hay fever symptoms is influenced by multiple factors, including climate and environment. Longer, more intense pollen seasons driven by climate change are exacerbating issues for many. Urban planning also plays a role: birch trees, commonly planted in UK cities for their rapid growth, produce copious amounts of pollen. A 2025 review in *Journal of Allergy and Clinical Immunology: In Practice* warned that wind-pollinated trees and grasses in built-up areas increase allergy risks.

Air pollution compounds the problem by attaching to pollen particles and carrying them deeper into the lungs. Anne Biggs, deputy head of clinical services at Allergy UK, advises sticking to standard treatments like non-sedating antihistamines, steroid nasal sprays, and eye drops. She recommends practical steps such as wearing wraparound sunglasses, applying barrier balm around nostrils, and showering after outdoor activities to reduce pollen exposure.

For severe cases, immunotherapy—also known as desensitisation therapy—offers a long-term solution. Patients receive gradually increasing doses of pollen extract over two to three years to retrain their immune systems. "We encourage a healthy diet to complement, not replace, standard hay fever management," Biggs says. While science continues to explore dietary and environmental interventions, for now, the best defense against allergies remains a combination of medical care, lifestyle adjustments, and vigilance.