If you or a loved one has allergies, you know how overwhelming they can be. They may take the form of seasonal allergies, food allergies, or allergies to medicine, to venom (like bee stings), or to pets.
Sometimes an allergy, like a peanut allergy, can be life-threatening. But most of the time, allergies are simply frustrating.
Even mild seasonal allergies can ruin your productivity and performance by causing brain fog, fatigue, stuffiness, watering eyes, and other irritating symptoms.
Fortunately, you can manage your allergies — and not just with allergy medication. A change in your diet can have a major impact on your immune and inflammatory responses, which can translate to allergy relief.
Finding the best diet for your allergies may take a little trial and error, but the results will be worth it.
This article will talk about what causes allergies, how can you manage them, and how diet can help you get relief from common allergens.
What Are Allergies?
Think of allergies as confusion in your immune system.
Your immune system is supposed to protect you from foreign substances that will harm you. With allergies, your immune system has an excessive response to things that are either harmless or less dangerous than your immune system thinks they are[*].
Often, the offending substance is pollen, mold, dust mites, venom (like bee stings), specific foods, medication, or pet dander.
In the case of skin allergies like contact dermatitis, trace amounts of a cosmetic or household ingredients can trigger an itchy skin rash.
Allergy symptoms typically occur in or around the body part that contacts the allergen. For example, breathing in dust, pollen or mold can cause respiratory issues like wheezing, sneezing, and coughing — as well as itchy eyes.
Foods and medications cause stomach problems, gas, or other GI issues.
The most severe allergic responses to foods, medications, or venom are called anaphylactic reactions. In anaphylaxis, the immune response spreads throughout the body, affecting multiple organ systems. Anaphylaxis can be fatal if not treated immediately.
How Do Allergies Develop?
Allergies develop via a process called “sensitization.”
Here’s how sensitization works, step by step[*]:
- You’re exposed to an allergen (for example: inhaling pollen)
- In response to pollen, your body produces immunoglobulin E (IgE) antibodies
- IgE antibodies attach to immune particles called mast cells
- Next time you breathe pollen, your mast cells release a variety of substances, including symptom-triggering compounds like histamine
- These substances cause allergy symptoms
Sensitization trains your immune system to recognize the allergen — be it pollen, mold, or fish — as a foreign invader. Your immune cells attack the allergen, and the collateral damage from this attack causes symptoms.
Some allergy symptoms come from histamine, a chemical that opens up your mucus membranes (causing a runny nose) and interferes with sleep.
High levels of histamine exacerbate allergies, and antihistamine drugs (like Benadryl) are often effective at reducing allergy symptoms[*].
Food Allergies vs. Seasonal Allergies
Seasonal allergies are not life-threatening. However, they are quite common, affecting about 30% of the US population. Symptoms from seasonal allergies — coughing, sneezing, breathing difficulties, brain fog, and nasal discharge — is called allergic rhinitis[*].
These symptoms are triggered by seasonal pollen or mold, or by non-seasonal irritants like dust, pets, and pests.
The sensitization process often begins in your first year of life, although it can also occur in adulthood. Your teens, twenties, and thirties are generally the worst decades for seasonal allergies[*]. After that, your allergies decrease — one of the perks of getting older.
Food allergies are less prevalent than seasonal allergies, but they’re also more severe. About one in 13 children and one in 25 adults suffer from a life-threatening food allergy — most commonly to peanuts, tree nuts, shellfish, milk, wheat, soy, or eggs[*].
Food allergies have been on the rise for the last couple decades, especially in children[*].
Food allergies develop similarly to seasonal allergies. Food allergies, however, are not the same as food intolerances.
Food Allergies vs. Food Intolerances
In the case of a food allergy, the offending food triggers a potentially life-threatening immune response driven by IgE antibodies.
Food intolerances, on the other hand, cause mild-to-severe (but not life-threatening) issues. Immune cells called IgA antibodies may play a role in food intolerances[*].
The most common food intolerances include:
- Celiac disease: An autoimmune disease caused by an inflammatory response to gluten or other grain-based proteins. Celiac commonly presents as GI symptoms, but can also cause “silent” damage to your intestinal walls which increases the risk for nutrient deficiencies and other complications[*][*].
- Non-celiac gluten sensitivity: Some people don’t have celiac antibodies, but still react poorly to gluten. Symptoms range from gas to fatigue to eczema[*].
- Lactose intolerance: A reaction to dairy products usually caused by deficiency in the milk-digesting enzyme, lactase. About 65% of people develop some degree of lactose intolerance after infancy. That number jumps to 75% for people of African descent, and 90% for East Asian people[*]. There’s a genetic component to lactose intolerance. So, if you struggle with dairy, you may lack the gene to produce lactase. Certain gut bacteria can also produce lactase, and decreased gut bug diversity may contribute to lactose intolerance. Taking a probiotic that contains Bifidobacterium animalis and/or Lactobacillus bulgaricus can help you train your gut to digest dairy again[*].
- Carbohydrate malabsorption: Some people can’t digest a group of carbohydrates called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) — and this malabsorption leads to gas, bloating, and IBS-like symptoms. A low-FODMAP diet or other gut healing therapies can help[*].
The bottom line is that food sensitivities are less severe than food allergies, but they can still cause a variety of symptoms.
Risk Factors for Developing Allergies
Allergies usually develop during childhood and they may persist throughout your life. Adults, however, can develop (or recover from) allergies at any time. It depends on the allergen, the state of the person’s immune system, and many other factors.
Genes are one component of allergies. For instance, having a parent with seasonal allergies more than doubles your chance of developing seasonal allergies yourself[*].
Also, most people with asthma — immune response-driven inflammation of the airways — also have allergic rhinitis[*].
Growing up on a farm, on the other hand, decreases allergy prevalence[*]. Researchers think it’s because farms are dirty, which leads into the first theory of allergy causes: the hygiene hypothesis.
The Hygiene Hypothesis
The hygiene hypothesis posits that modern environments are simply too clean. In our sanitized modern world, you aren’t exposed to enough dirt, allergens, or microbes — and therefore your immune system isn’t “trained” to properly respond to its environment.
There’s a fair amount of evidence to support the hygiene hypothesis:
- Children growing up with pets or on farms develop fewer allergies[*][*]
- Children who drink raw milk, which is rich in bacteria and may contain small amounts of pathogens, develop fewer allergies[*]
- Antibiotic usage and formula feeding are both linked to increased rates of asthma later in life[*][*]. Breastfeeding, on the other hand, protects against asthma[*].
Researchers believe that exposure to a variety of microbes when you’re young trains your immune system to become more robust and makes it less likely to produce excess IgE antibodies, which are major drivers of allergies[*].
The Microbiome and Allergies
When your gut is healthy, it only lets nutrients out into your bloodstream. That means that food particles, toxins, and other compounds stay in your digestive system until you can excrete them.
But if your gut barrier becomes permeable — a condition called leaky gut, or intestinal permeability — food particles can slip out into your bloodstream, where your immune system labels them as invaders and mounts an attack against them.
One major cause of leaky gut is a disrupted gut biome.
Researchers have shown that giving mice antibiotics — killing all gut bacteria, beneficial and non-beneficial — causes the mice to develop intestinal permeability[*].
Other researchers were able to “desensitize” food allergies in mice by colonizing their guts with beneficial Clostridia bacteria[*].
Based on evidence in mice, it seems that the number of good bacteria in your gut may play a role in your allergic response, and that if you improve your gut health, food sensitivities may go away.
Too Much Histamine
Histamine is an important compound involved in blood vessel health, stomach acid production, and immune response. You need some histamine to fulfill basic functions, but many folks have too much histamine, which can worsen allergies[*].
What might cause excess histamine?
- A deficiency in diamine oxidase, an enzyme that breaks down histamine[*]
- Eating histamine-rich foods (more on this later)
- An overgrowth of histamine producing bacteria, like lactobacilli, in the gut[*]
If you have allergies, the severity of your allergic reactions will depend, in part, on the total amount of histamine circulating through your body.
Histamine, as you learned earlier, is also produced by immune cells as part of the allergic response. This can be especially troublesome if you already have excess histamine in your system, thanks to your diet or gut biome.
5 Foods to Help with Seasonal Allergies
Here are five foods that may help with seasonal allergies.
#1: Fermented Foods
The beneficial bacteria in fermented foods can improve your gut health and immune function, which may help you avoid seasonal allergies.
People who eat fermented foods have more immune-regulating lactic acid bacteria, as well as greater overall gut diversity[*]. Greater gut diversity can reduce your allergy symptoms[*].
It’s easy to add fermented foods to your diet. Popular choices include:
- Sauerkraut
- Kimchi
- Kefir
- Yogurt
- Kombucha
- Natto
That said, fermented foods aren’t for everyone. The next section discusses why.
#2: Low-Histamine Foods
Some fermented foods are high in histamine, which can worsen allergy symptoms if you’re histamine intolerant[*].
Give fermented foods a try and see how you feel. If your allergy symptoms get worse, pass on fermented foods and try taking a probiotic that’s low in histamine-producing Lactobacillus bacteria.
You might also try a low-histamine diet, which means avoiding cocoa, aged cheese, citrus fruits, spinach, shellfish, avocados, and fermented foods.
#3: Fiber-Rich Foods
You can’t digest fiber, but your gut bacteria can. Fiber feeds good gut bacteria and helps them edge out damaging gut bacteria, which may make a difference when it comes to allergy symptoms.
But the more important part of a high-fiber diet is short-chain fatty acid (SCFA) production.
When your gut bacteria digest fiber, they create SCFAs, beneficial compounds that decrease inflammation, strengthen your gut barrier, and even improve IBS and Crohn’s disease symptoms[*][*].
SCFAs also decrease symptoms of allergic airway disease in mice[*].
Increase your fiber intake by eating plenty of low-carb vegetables and low-sugar fruits.
#4: Egg Yolks and Liver
Egg yolks and liver are the best dietary sources of retinol, or preformed vitamin A.
Many folks struggle to get enough retinol through diet. Plant-based vitamin A, or beta carotene, is more abundant in common foods — but depending on your individual biology, it may not get converted to retinol in your body[*]. For that reason, preformed vitamin A is better.
Retinol is a precursor to retinoic acid, a compound that helps regulate your immune system. Specifically, retinoic acid mediates T-regulatory cell function[*] — and T cells are involved, along with antibodies, in causing allergic reactions.
Egg yolks and beef liver are the two best sources of retinol. They may help balance your immune response so it doesn’t respond excessively to allergens.
#5: Raw Honey, Bee pollen, or Propolis
Unprocessed honey contains a broad array of antioxidants, enzymes, and pollen. As it turns out, consuming bits of pollen helps desensitize your immune system to the effects of airborne pollen.
In one 2011 study, researchers gave 44 allergy sufferers either normal honey or raw birch pollen honey during pollen season. The raw honey group had a 60% lower allergy symptom score than the regular honey controls did[*]. The raw honey group also had twice as many no-symptom days.
If you’re on a low-carb keto diet, however, raw honey may not be an option. (Too much sugar!). If that’s you, consider supplementing with pollen or propolis directly, two other bee products that reduce allergy symptoms[*]. Mix these into your keto smoothies and you won’t even taste them.
How the Keto Diet Might Help Your Allergies
Can keto help with allergies? While there’s no science specifically addressing this question, keto may nonetheless be a useful tool in the allergy-reduction toolbelt. There are a couple reasons why.
For one, allergies can be aggravated by food intolerances. When you eat a problem food, it disrupts your gut, which in turn hampers immune function.
But on a clean keto diet, you’re gluten-free, restricting carbs, eating lots of healthy fats like olive oil, and avoiding processed junk. With fewer potential problem foods, you may find your allergy symptoms decrease.
“If you are a Westerner with some gut issues,” writes Dr. Michael Ruscio in his widely-acclaimed 2018 book Healthy Gut, Healthy You, “a high-carb and prebiotic-rich diet might be the exact opposite of what you need. It may feed bacteria that your immune system is attacking.”
In other words: Folks with gut issues may fare best on a low-carb, low-prebiotic fiber diet. And anything that helps the gut should theoretically help with allergies.
That said, the best diet for allergies depends on your individual biology. You may do best on a high-fiber diet rich in fermented foods, or a low-histamine diet, or you may thrive on a keto diet.
Do some experimentation and find out what works for you. You may find surprising relief this allergy season.