understanding hay fever and the gut connection.

Understanding Hay Fever: A Widespread Seasonal Challenge

With hay fever season fast approaching, over 500 million people worldwide are preparing for months of sneezing, itchy eyes, and congestion, making hay fever or allergic rhinitis (AR) one of the most common seasonal conditions. But what causes it, and more importantly, how can it be effectively managed?

Why Does Hay Fever Occur?

Hay fever is triggered when the immune system overreacts to pollen, releasing histamine and causing symptoms like sneezing, runny nose, and itchy eyes. The season spans from tree pollen in March to weed pollen in September. As a result, many people experience symptoms for months at a time.

While not a serious illness in itself, hay fever can disrupt daily life by impacting sleep quality, productivity, and overall well-being.

The Gut-Allergy Connection: How Gut Health Influences Hay Fever

Emerging research highlights a growing connection between gut health and allergic conditions, including hay fever. The gut microbiome, a community of trillions of bacteria in our digestive system, plays a crucial role in regulating the immune system. When the balance of this microbiome is disrupted due to factors like diet, stress, or illness, it can lead to your immune system being overactive, which contributes to allergic conditions like hay fever.

A key aspect of this is histamine intolerance, which can worsen hay fever symptoms. Histamine is released when the body reacts to allergens like pollen, but some people have difficulty breaking it down due to a deficiency in an enzyme called diamine oxidase (DAO), which is produced in the gut. Conditions like dysbiosis (an imbalance in gut bacteria) or leaky gut, where the gut lining becomes permeable, can impair DAO production and result in histamine buildup. This leads to more intense allergic reactions and worsened symptoms of hay fever.

The Role of Diet in Hay Fever

Emerging research suggests that diet influences immune health and may affect hay fever risk. Research has linked Western diet high in processed snacks, trans fat and sugar to a higher likelihood of hay fever. As diet is modifiable, these findings could have clinical relevance, especially for those at risk. Further research is needed to understand the biological, environmental, and genetic factors involved.

What Can You Do?

1. Eat antioxidants
   
   Diet is a crucial source of antioxidants, which help combat systemic oxidative stress: a key driver of inflammation and allergic responses. Fruits and vegetables rich in antioxidants have been linked to a lower risk of allergic diseases, including hay fever and asthma. More specifically, you can focus on:

• Eating quercetin-rich foods such as onions, garlic, apples, berries, kale, and red grapes help stabilise mast cells which would normally release histamine and cause  many hay fever symptoms like sneezing and itching.

• Focus on vitamin C-rich foods like blackcurrants, blueberries, peppers, broccoli, kiwi, and mango can help lower histamine levels in the body. Vitamin C is also an antioxidant that combats inflammation, which can help alleviate the discomfort of hay fever.

2. Support your gut health
   
   A healthy gut microbiome plays a key role in regulating immune responses by reducing inflammation and eventually alleviating symptoms of hay fever. Probiotics and fermented foods like kimchi, sauerkraut, and yoghurt can help balance gut bacteria by introducing more good bacteria in your gut, while fibre-rich foods such as oats, nuts, and vegetables promote beneficial bacteria to support immune function.

3. Hydrate
   
   Staying hydrated helps thin mucus and clear nasal congestion. Ginger tea specifically has been researched about its anti-inflammatory benefits and has also been associated with relieving symptoms of hay fever.

4. Sleep more and manage stress
   
   Good sleep helps manage inflammation and also helps with keeping a strong immune system as this is the time our body takes to recover. Aim for 7-9 hours of rest. Managing stress is also crucial for reducing allergy severity.

5. Be mindful of alcohol and sugar
   
   Alcohol and sugar can worsen inflammation and histamine release. Red wine, in particular, contains sulphites and histamines that may trigger symptoms. Moderating alcohol intake and reducing sugar might help with severity of symptoms.

Conclusion

While hayfever can be frustrating, making small changes to your diet and lifestyle can help ease symptoms. Incorporate more antioxidant foods, support your gut with probiotics, stay hydrated, and prioritise sleep. With these steps, you can get through the season with fewer sniffles and more sunshine enjoyment!

References

Han, P., Gu, J-Q., Li, L-S., Wang, X-Y., Wang, H-T., Wang, Y., Chang, C., & Sun, J-L. (2021). The association between intestinal bacteria and allergic diseases—cause or consequence? Frontiers in Cellular and Infection Microbiology, 11, 650893. https://doi.org/10.3389/fcimb.2021.650893

Kawamoto, Y., Ueno, Y., Nakahashi, E., Obayashi, M., Sugihara, K., Qiao, S., Iida, M., Kumasaka, M. Y., Yajima, I., Goto, Y., Ohgami, N., Kato, M., & Takeda, K. (2016). Prevention of allergic rhinitis by ginger and the molecular basis of immunosuppression by 6-gingerol through T cell inactivation. Journal of Nutritional Biochemistry, 27, 112-122. https://doi.org/10.1016/j.jnutbio.2015.08.025

Rezapour, H., Fereidouni, M., Asadi, Z., Saharkhiz, M., Ayadilord, M., Mahmoudzadeh, S., Shadmand Foumani Moghadam, M. R., Ferns, G. A., & Bahrami, A. (2022). A Western dietary pattern is related to higher risk of allergic rhinitis in young women. Revue Française d'Allergologie, 62(5), 470-477. https://doi.org/10.1016/j.reval.2021.08.007

Schnedl, W. J., & Enko, D. (2021). Histamine intolerance originates in the gut. Nutrients, 13(4), 1262. https://doi.org/10.3390/nu13041262