Root Causes to Seasonal Allergies and How to Heal from the Source
- Mary Kate Fuller, MS, CNS, LDN, CHHP
- May 12, 2022
- 6 min read
Updated: 4 days ago
It’s that time of year again when the weather finally eases, the birds are singing, and the flowers and trees are in bloom. While some welcome the season joyfully, others struggle with the return of allergy symptoms. Have you ever wondered why you struggle during the Spring?
What is Allergic Rhinitis (aka: Hay fever or seasonal allergies)?
Allergic Rhinitis is an over-reaction of the immune system due to a long-standing, gradual, accumulation of irritation to the immune system by various different factors.
Symptoms can include:
Congestion (nose, head, ears, lungs)
Runny nose, postnasal drip
Sneezing
Watery eyes
Sore throat
Itchy eyes, nose or throat
Ear pressure or increased ear wax
Headaches
Cough
Fatigue
Skin rashes/hives
The first step in addressing seasonal allergies is asking:
“WHY is the immune system compromised in the first place?”
Nearly 40% of the population worldwide – and more than fifty million Americans – report suffering from allergies each year. Each one of the following factors, by itself, can lead to chronic seasonal allergies, but most often, it's a combination that leads to and intensifies symptoms.
Understanding and Healing Seasonal Allergies: A Functional Medicine Approach
Seasonal allergies can be a frustrating and disruptive issue for many. While conventional medicine often focuses on symptom management, functional medicine aims to address the root causes of allergies and heal the body from within. By identifying underlying imbalances in systems like the immune system, gut, liver, and adrenals, you can work to reduce the frequency and severity of allergic reactions.
Let’s explore the root causes of seasonal allergies from a functional medicine perspective and how to heal from the source with simple dietary and lifestyle changes.
Root Causes of Seasonal Allergies:
Gut Health Imbalance: The gut is home to about 70-80% of your immune system. An imbalance in gut bacteria, often referred to as dysbiosis, can contribute to inflammation and allergic reactions. Leaky gut syndrome, where the intestinal lining becomes permeable, can allow allergens and toxins to enter the bloodstream, triggering immune responses.
Low Stomach Acid and Allergies
Many people with seasonal or environmental allergies also experience digestive symptoms—like bloating, reflux, or heartburn—that point to low stomach acid (hypochlorhydria). While it may seem unrelated, low stomach acid can actually weaken your body’s first line of defense against allergens and pathogens getting into the system.
Poor protein digestion due to low stomach acid can increase the overall inflammatory burden on the immune system.
Inadequate stomach acid impairs mineral absorption (like zinc and magnesium), which are essential for immune regulation and mucosal barrier integrity.
A weakened gut barrier (a common result of low stomach acid and dysbiosis) allows more allergens to enter circulation, triggering immune overreactions not just to food, but also to environmental triggers like pollen, dust, and mold.
Supporting optimal stomach acid production—through gentle digestive bitters, lemon juice or apple cider vinegar before meals (if tolerated), and managing stress—can significantly calm the immune system and reduce the severity of seasonal allergies.
If this is you - try the Baking Soda Challenge for a simple, at home way to check in on your stomach acid levels.
How to Heal:
Eat Gut-Healing Foods: Incorporate bone broth, fermented foods (like kimchi, sauerkraut, and kefir), and fiber-rich vegetables to support a healthy gut microbiome.
Avoid Common Irritants: Limit processed foods, sugar, and alcohol, which can feed harmful bacteria and contribute to inflammation.
Supplement with Probiotics: Probiotics help restore gut balance. Look for strains like Lactobacillus and Bifidobacterium to help reduce inflammation and support immune function.
If you need help identifying whether your gut needs healing, read HERE.
Food Sensitivities and Cross-Reactivity: Certain foods, like dairy, gluten, and processed foods, can exacerbate allergic reactions by triggering inflammation and immune dysregulation. In some cases, your body may confuse proteins in certain foods with environmental allergens, causing cross-reactivity (for example, you might react to both ragweed and bananas).
When Food and Environmental Allergies Overlap
A lesser-known, yet significant contributor to seasonal allergy symptoms is cross-reactivity. This happens when your immune system mistakes proteins in food for similar proteins found in environmental allergens like tree, grass, or weed pollens. This phenomenon, known as oral allergy syndrome (OAS) or pollen-food allergy syndrome, can intensify symptoms during allergy season.
For example:
People allergic to birch pollen may react to apples, carrots, celery, or hazelnuts.
Those sensitive to ragweed pollen might experience issues with bananas, cucumbers, melon, or sunflower seeds.
Individuals with grass allergies may react to tomatoes, potatoes, or oranges.
This immune confusion signals deeper gut-immune dysfunction and increased permeability (leaky gut). Addressing gut health, immune regulation, and inflammation helps reduce both food sensitivities and environmental allergy flares.
How to Heal:
Limit Inflammatory Foods: Avoid dairy, gluten, and foods high in refined sugars. These can promote inflammation and worsen allergic responses.
Try an Elimination Diet or Food Sensitivity Testing: Identifying and eliminating food sensitivities can dramatically improve allergy symptoms.
Consider Anti-Inflammatory Foods: Add anti-inflammatory foods like turmeric, ginger, and omega-3 rich foods (such as salmon and chia seeds) to reduce systemic inflammation.
Liver Congestion: Your liver plays a key role in detoxifying the body and eliminating environmental toxins, including allergens. If the liver is overwhelmed or sluggish, it may struggle to properly process and remove these substances, leading to heightened allergic reactions.
How to Heal:
Support Liver Detoxification: Incorporate liver-supporting foods (think bitter) like dandelion root, asparagus, artichoke, beets, and leafy greens. These foods help promote bile production and detoxification.
Limit Alcohol and Toxins: Reduce or eliminate alcohol and processed foods that can burden the liver.
Supplement with Liver Support Like Milk Thistle: Milk thistle is a powerful herb that helps regenerate liver cells and supports detoxification.
Adrenal Dysfunction: Chronic stress and overworked adrenal glands can exacerbate allergic reactions. When the adrenals are underactive, it can lead to an imbalance in the stress hormone cortisol, which plays a crucial role in regulating inflammation. This can leave you more susceptible to seasonal allergies.
How to Heal:
Manage Stress: Practice stress reduction techniques such as yoga, meditation, deep breathing, or journaling. Reducing stress helps balance cortisol levels and support overall immune health.
Support the Adrenals: Incorporate adaptogens like ashwagandha, holy basil, and Rhodiola rosea, which help regulate cortisol and support adrenal function.
Prioritize Sleep: Ensure you’re getting 7-9 hours of quality sleep each night, as sleep plays a critical role in immune function and hormone balance.
Immune System Imbalance: Seasonal allergies are essentially a form of immune system overreaction. The immune system mistakes harmless particles, like pollen, for harmful invaders and releases inflammatory chemicals, like histamine, to fight them off. This reaction can be more pronounced when the immune system is imbalanced or under stress.
How to Heal:
Incorporate Immune-Balancing Foods: Add foods rich in vitamin C (like citrus, bell peppers, and broccoli) and vitamin E (like nuts and seeds), which support immune health and reduce inflammation.
Supplement with Quercetin: Quercetin is a natural antihistamine and anti-inflammatory. It helps stabilize mast cells (which release histamine) and reduce allergic symptoms.
Include Curcumin: Curcumin, the active compound in turmeric, has potent anti-inflammatory properties that can help modulate the immune system and reduce allergy symptoms.
Foods to Limit for Seasonal Allergy Relief:
To support your body’s ability to heal from seasonal allergies, it’s important to avoid foods that can promote inflammation and exacerbate symptoms:
Dairy: Dairy can increase mucus production and aggravate sinus congestion.
Gluten: Gluten can promote gut inflammation and compromise immune function.
Processed Foods and Sugars: These foods feed bad bacteria in the gut and can increase systemic inflammation.
Nightshades (e.g., tomatoes, peppers, eggplant): These can aggravate inflammation for some individuals.
Alcohol: Alcohol can suppress immune function and dehydrate the body, making allergy symptoms worse.
Supportive Foods for Allergy Healing:
Incorporating these foods into your diet can help support the immune system, reduce inflammation, and promote overall wellness:
Omega-3 Rich Foods: Salmon, chia seeds, flaxseeds, and walnuts help reduce inflammation and support brain and immune health.
Leafy Greens: Baby kale, spinach, and Swiss chard are high in magnesium and antioxidants, which help reduce inflammation.
Anti-Inflammatory Spices: Turmeric, ginger, and garlic have powerful anti-inflammatory effects that support the immune system and reduce histamine release.
Vitamin C-Rich Foods: Citrus fruits, bell peppers, and strawberries provide immune-boosting vitamin C, which can help manage allergic inflammation.
Supplements to Consider for Allergy Support:
Probiotics: Help balance gut bacteria, reduce inflammation, and support immune function.
Quercetin: A natural antihistamine that helps prevent histamine release and reduce allergic reactions.
Vitamin C: Supports immune health and can reduce the severity of allergic symptoms.
N-Acetyl Cysteine (NAC): Supports liver detoxification and helps thin mucus to ease respiratory symptoms (sinus and chest congestion).
Curcumin: A potent anti-inflammatory supplement that can modulate immune responses and reduce allergy symptoms.
Ashwagandha: An adaptogen that helps manage stress and regulate cortisol levels, supporting adrenal health and reducing inflammation.
Omega-3 Fatty Acids: Fish oil or algae-based omega-3 supplements can help reduce inflammation and support immune function.
Conclusion:
Seasonal allergies can be a result of several underlying imbalances, including poor gut health, liver congestion, food sensitivities, and adrenal dysfunction. By addressing these root causes, you can support your body’s natural healing processes and reduce allergic reactions over time.
Focus on a diet rich in anti-inflammatory foods, eliminate triggers like gluten and dairy, and incorporate supplements that support gut health, liver detox, and immune balance. With a functional medicine approach, you can not only manage seasonal allergies but also work toward healing from the source, leading to long-term relief and better overall health.
Want help choosing the right supplements for you? Visit our supplement store for trusted, quality options HERE.

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