Seasonal Allergies: Histamine, PMS, & Gut Health

In this newsletter, let's explore the connection between high histamine, menstrual health, digestive health and how you can naturally support your seasonal allergies.

Spring is around the corner and if you’re already bracing yourself for months of sneezing, congestion, and itchy eyes, I see you. Seasonal allergies can make even the best time of year miserable, but here’s the thing — there’s a lot you can do beyond just popping an antihistamine and hoping for the best.

Let’s break down:

• What seasonal allergies are

• Every single symptom (yes, even the weird ones)

• The histamine connection to estrogen & gut health

• Lifestyle changes that help

• The best herbs & supplements to naturally support your body

By the end, you’ll have a game plan to help you navigate allergy season without feeling miserable.

What Are Seasonal Allergies?

Seasonal allergies happen when your immune system overreacts to environmental allergens like pollen, mold spores, and grass. Your body sees these harmless particles as invaders and releases histamine — a chemical that triggers inflammation, mucus production, and those classic allergy symptoms.

For some people, allergies are mild. For others, they hit hard and the symptoms aren’t just limited to a runny nose.

Symptoms of Seasonal Allergies (All of Them!)

Most people think of sneezing, congestion, and itchy eyes but the effects of histamine go way beyond that. Here’s the full list:

• Runny or stuffy nose

• Sneezing

• Itchy, watery, red eyes

• Postnasal drip (constant throat clearing)

• Scratchy or sore throat

• Sinus pressure & headaches

• Coughing

Less Obvious Symptoms:

• Fatigue (histamine is inflammatory and can drain your energy)

• Brain fog (histamine can affect neurotransmitters like dopamine)

• Dizziness & lightheadedness

• Increased anxiety or irritability

• Insomnia (histamine is a wakefulness neurotransmitter)

• Digestive issues like bloating, nausea, and irregular bowel movements

• Increase in food sensitivities

• Skin reactions (acne, hives, rashes, worsening eczema)

• Menstrual symptoms (cramps, water retention, period flu)

If you’re dealing with multiple of these, your histamine bucket is overflowing.

The Histamine & Estrogen Connection

If you experience intense allergy like symptoms before your period (think fatigue, congestion, headaches, nausea, and body aches) you might be dealing with what’s called the period flu. This phenomenon isn’t an actual flu but rather an inflammatory response tied to rising histamine, estrogen fluctuations, and prostaglandins.

Why does this happen? Estrogen stimulates mast cells to release histamine, which triggers inflammation and worsens allergy-like symptoms. Histamine in turn stimulates even more estrogen production, creating a vicious cycle where both continue to rise. If your body doesn’t break down histamine efficiently, either due to gut issues or sluggish liver detox, symptoms hit even harder.

This is why many women with estrogen dominance experience worse allergies, migraines, and inflammation around ovulation and the luteal phase.

Histamine also increases prostaglandins, hormone-like compounds that cause uterine cramping, pain, and inflammation. If your histamine is chronically high, you may notice:

• Worsening PMS symptoms (bloating, mood swings, cramping)

• More painful periods (due to higher prostaglandin levels)

• Increased nausea, dizziness, and flu-like symptoms before menstruation

There’s also growing evidence that histamine plays a role in estrogen-driven menstrual conditions like:

• Endometriosis: A 2021 study found that women with endometriosis had higher mast cell activation and histamine levels in pelvic tissue, contributing to pain and inflammation.

• Fibroids: Research suggests that fibroid growth is influenced by estrogen and inflammatory compounds like histamine and prostaglandins.

• Polyps & Heavy Bleeding: Excess histamine may lead to increased vascular permeability, which contributes to heavier, prolonged menstrual bleeding.

The Histamine & Gut Health Connection

Your gut plays a huge role in how well your body breaks down histamine. If your gut isn’t functioning optimally, histamine can build up and trigger symptoms, worsen PMS, and contribute to inflammation.

The main enzyme responsible for breaking down histamine in the gut is DAO (diamine oxidase). If DAO levels are low then histamine from food, gut bacteria, and mast cells accumulates and worsens symptoms.

What lowers DAO?

• Leaky gut: Damaged intestinal lining reduces DAO production and allows histamine to enter circulation more easily

• SIBO (Small Intestinal Bacterial Overgrowth): Some gut bacteria produce histamine, overwhelming your system.

• Nutrient deficiencies: DAO requires vitamin B6, copper, and magnesium

• Alcohol, processed foods, and certain medications: block DAO function

Your gut microbiome also determines how well your body processes histamine. Some bacteria increase histamine, while others help break it down.

Histamine-Producing Bacteria (Worsen Symptoms):

• Lactobacillus casei & Lactobacillus reuteri (found in some probiotics & fermented foods)

• Escherichia coli (common in gut imbalances like SIBO)

• Morganella, Klebsiella, & Citrobacter (pathogenic bacteria in gut infections)

Histamine-Degrading Bacteria (Help Clear Histamine):

• Bifidobacterium infantis & Bifidobacterium breve

• Lactobacillus plantarum & Lactobacillus rhamnosus

• Akkermansia muciniphila

If you’re taking a probiotic, make sure it supports histamine breakdown instead of increasing it.

Lifestyle Based Support for Seasonal Allergies

Addressing allergies naturally isn’t just about supplements—your daily habits matter a lot.

1. Reduce Exposure to Allergens

• Use HEPA filters in your home & car

• Shower at night to wash off pollen

• Keep windows closed during peak pollen hours (morning & evening)

• Use a nasal rinse (Neti pot or saline spray) to flush allergens from your sinuses

2. Support Estrogen Detox

• Eat cruciferous veggies (broccoli, cauliflower, Brussels sprouts)

• Increase fiber intake to help bind and excrete excess estrogen metabolites

• Support your liver with herbal teas dandelion tea, milk thistle, and turmeric

• Get enough magnesium and B vitamins

3. Heal Your Gut

• Eat a wide variety of fruit and vegetables in your diet — variety fosters a more diverse gut microbiome

• Eat anti-inflammatory foods (bone broth, wild-caught fish, berries, leafy greens, olive oil, etc.)

• Support digestion with bitters before meals

• Avoid ultra processed foods & alcohol (both block DAO enzyme)

• Include quercetin-rich foods in diet (onions, apples, capers)

Herbal Support for Seasonal Allergies

Herbs work by stabilizing mast cells, reducing inflammation, and improving histamine breakdown.

• Nettle Leaf: Natural antihistamine & anti-inflammatory

• Butterbur: Helps with congestion & sinus pressure

• Quercetin: Stabilizes mast cells to prevent histamine release

• Eyebright: Great for itchy, watery eyes

• Reishi Mushroom: Modulates the immune system & reduces allergy symptoms

Supplements for Allergy Relief

If your symptoms are severe, adding in targeted supplements can make a big difference.

• Quercetin + Bromelain: Reduces histamine & inflammation

• Vitamin C: Helps degrade histamine

• DAO Enzyme: If you struggle with histamine breakdown

• Magnesium Glycinate: Calms inflammation & supports DAO

• Probiotics: Especially Lactobacillus rhamnosus & Bifidobacterium bifidum

• Omega-3s: Lowers inflammation & supports immune balance

Your Allergy Game Plan

Seasonal allergies are frustrating, but they’re not just something you have to suffer through. By addressing histamine, estrogen balance, and gut health, you can lower your allergy response naturally.

As always, this information is meant to be educational and should not replace medical advice from your trusted healthcare professional.