If you have histamine intolerance, you probably don't have to think too hard to imagine a world where allergies run rampant, and acid reflux ruins every meal.
When your problem started, you likely turned to your medicine cabinet to take advantage of a tiny molecular superhero to save the day. That’s right, we're talking about antihistamines.
Histamine blockers are drugs that help manage uncomfortable, and sometimes, debilitating allergic reactions. They come to the rescue for anything from hives to a runny nose, trouble breathing to heartburn, and abdominal discomfort to heart palpitations.
What are these seemingly miraculous drugs and how do they work? Today we'll dive into the world of histamine blockers and uncover their secrets. But first, let's recap the ins and outs of histamine...
Histamine: What is it and What Does it Do?
Histamine is one of a group of chemical compounds called biogenic amines. It is a signaling molecule and neurotransmitter, sounding the alarm when your immune cells encounter a potential invader (1).
It is released from mast cells in your body, triggering an immune response to neutralize bacteria, viruses, and allergens. Histamine is also involved in the inflammatory reaction when you injure yourself.
Many of the symptoms associated with an allergic reaction are the result of histamine actions in the body. Itching, sneezing, inflammation, and even stomach acid production can also all be signs of histamine release.
Antihistamine Medication
If you have a known allergy or you regularly experience symptoms associated with elevated histamine levels, you might be familiar with histamine blockers. These are medications that do just that: blocks the effects of histamine.
The biogenic amine histamine can only work when it binds to one of four types of histamine receptors, designated H1, H2, H3, and H4. Those histamine blockers I just mentioned, also called antihistamines, are chemically created to prevent histamine from binding to these histamine receptors, especially the H1 and H2 receptors (2,3). So, let's take a look at each one.
H1 Histamine Blockers
H1 antihistamines are categorized into two classes: first and second generation drugs. While the two generations generally have the same action, first generation H1 histamine blockers are able to have an effect on the brain as they're designed to be able to cross the blood-brain barrier more easily. That means, compared to second generation histamine blockers, first generation blockers can to H1 receptors in the brain along in addition to H1 receptors found throughout the rest of the body.
Second generation medications cannot cross over into the brain, binding only to receptors in other parts of the body. These other receptors in the body include those found in blood vessels and the smooth muscles of the respiratory and digestive systems.
As a result of the ability to bind to different histamine receptors, the first and second generation H1 blockers can have different therapeutic and side effects.
Therapeutic Effect of First and Second Generation H1 Histamine Blockers
H1 Histamine blockers are used to treat the following allergic reactions:
- Runny nose and sneezing
- Red, itchy, teary eyes
- Hives and skin rashes
- Sinusitis
- Itchy skin
- Angioedema (swelling under the skin)
- Difficulty breathing
- Motion sickness, nausea, and vomiting
H2 Histamine Blockers
Histamine 2 (H2) blockers bind to histamine receptors found mainly in the stomach. They reduce the production of stomach acid and are, therefore, typically used to treat conditions caused by excessive stomach acid production, including:
- Peptic ulcers
- Acid reflux
- Gastritis
Common Side Effects of H1 and H2 Histamine Blockers
In general, antihistamine medication is considered safe. Not everyone who takes antihistamine drugs will experience adverse effects, but some people do.
Because various antihistamine medications work by binding to different histamine receptors, they cause a range of potential side effects (4).
Drowsiness is a common side effect of first generation H1 receptor blockers.
Both first and second generation H1 antihistamines can cause dry mouth, blurred vision, and constipation.
Histamine 2 receptor blockers may cause headaches, dizziness, diarrhea, constipation, and nausea.
It’s important to note that these antihistamines can interact with other drugs. So, it is highly recommended to consult with your doctor before taking histamine blockers if you take any other medication.
Also talk to your healthcare provider if you are pregnant or breastfeeding, have health conditions such as diabetes, epilepsy, or high blood pressure, or have an enlarged prostate and difficulty passing urine.
Over-The-Counter vs Prescription Histamine Blockers
Many histamine medications are available without a prescription. These over-the-counter drugs include H1 blockers used to treat common allergies and some H2 blockers for managing heartburn (5).
Sometimes, you might need a different type of medication or a stronger version of those you can buy over-the-counter. Talk to your doctor if you have allergies that persist for several months, are living with those that cause chronic sinus infections, or you have developed symptoms that interfere with your daily routine. You may also need prescription antihistamines if your symptoms are not controlled by over-the-counter drugs or you've experienced serious side effects as a result of using them.
Natural Alternatives for Blocking Histamine
For people with histamine intolerance, antihistamines can make matters worse. Ordinarily, the chemical is deactivated once it has done its job neutralizing potential threats. But low levels of the enzyme responsible for breaking down histamine, called diamine oxidase (DAO), results in high histamine levels and the wide range of symptoms that goes with it.
Fortunately, there are some natural alternatives for managing elevated histamine levels. These are some of the most effective supplements for those with histamine intolerance:
- Quercetin: A flavonoid found in foods like onion, apples, and berries, quercetin is known to be a natural antihistamine.
- Vitamin C: A potent antioxidant and immune booster, vitamin C can reduce symptoms of histamine intolerance.
- Bromelain: A phytochemical found in pineapple stems, bromelain is effective for treating several histamine intolerance symptoms (6).
- Stinging nettle: Certain compounds in stinging nettle interfere with histamine production and binding to histamine receptors (7).
- Butterbur: Some studies suggest that butterbur can be as effective as antihistamine drugs for allergies (8).
- Probiotics: Low-histamine probiotics can help reduce histamine levels in the gut.
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Green tea: The EGCG in green tea has been shown to be an effective antihistamine plant chemical (9).
What to Eat to Avoid Histamine Overload
Supplements are useful for managing elevated histamine levels, but what you eat is the key to long-term success. That’s because some foods, like aged cheeses, yogurt, wine, and certain fruits and vegetables contain high levels of histamine.
Other foods are histamine liberators, especially those that contain a lot of chemical additives. In other words, they trigger the release of histamine in the gut.
Knowing which foods are contributing to your histamine overload and mind-boggling symptoms enables you to take control of your condition. To get you started on the road to a life free from bothersome histamine symptoms, we have created a free low-histamine diet download. Click on the link below to take advantage of this useful tool.
Get Histamine Reactions Under Control
Even with histamine intolerance, you can look forward to a world where your rampant allergy symptoms no longer dictate your life. Even though histamine blockers may not be the answer for you, they can be useful as part of a holistic treatment plan.
A low-histamine diet combined with effective natural antihistamine supplements can improve your quality of life, bringing relief from allergic rhinitis, streaming eyes, heart palpitations, and many more pesky symptoms.
References
- Mandola A, Nozawa A, Eiwegger T. Histamine, histamine receptors, and anti-histamines in the context of allergic responses. LymphoSign Journal [Internet]. 2019 Jun 1 [cited 2024 Sep 24];(2):35–51.
- Seldeslachts A, Peigneur S, Tytgat J. Histamine Receptors: Ex Vivo Functional Studies Enabling the Discovery of Hits and Pathways. Membranes [Internet]. 2023 Dec 2 [cited 2024 Sep 24];(12):897.
- Farzam K. Antihistamines - StatPearls - NCBI Bookshelf [Internet]. National Center for Biotechnology Information. [cited 2024 Sep 24].
- Antihistamines for allergies: MedlinePlus Medical Encyclopedia [Internet]. MedlinePlus - Health Information from the National Library of Medicine. [cited 2024 Sep 24].
- Allergy Medicines: OTC or Prescription? [Internet]. WebMD. WebMD; 10AD [cited 2024 Sep 24].
- BROMELAIN: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews [Internet]. WebMD - Better information. Better health. [cited 2024 Sep 24].
- Stinging nettle Information | Mount Sinai - New York [Internet]. Mount Sinai Health System. [cited 2024 Sep 24].
- Jackson CM, Lee DKC, Lipworth BJ. The effects of butterbur on the histamine and allergen cutaneous response. Annals of Allergy, Asthma & Immunology [Internet]. 2004 Feb [cited 2024 Sep 24];(2):250–4.
- Hassanen EI, Kamel S, Issa MY, Mohamed WA, Mansour HA, Mahmoud MA. Phenolic-rich fraction of green tea attenuates histamine-mediated cardiopulmonary toxicity by inhibiting Cox-2/NF-κB signaling pathway and regulating oxidant/antioxidant balance. Beni-Suef University Journal of Basic and Applied Sciences [Internet]. 2024 Jan 12 [cited 2024 Sep 24];(1).
Anita Tee
My name is Anita Tee. I'm a nutritional scientist specializing in histamine intolerance. I hold a Master of Science in Personalized Nutrition and a Bachelor of Science in Human Biology and Psychology.
For the past ten years, I have used my experience in nutritional and medical health sciences to create a scientifically backed, natural approach to healthcare that relies 100% on evidence-based research.
As I previously suffered from - and overcame - histamine intolerance, my focus is to increase recognition and expand the available resources and protocols for resolving the disorder. To date, I have helped over 4,000 individuals fully resolve or better manage their histamine intolerance symptoms.
