
Discover 10 powerful facts about histamine and allergic reactions. Learn symptoms, the role of cortisol, and how quercetin acts as a natural antihistamine.
Table of Contents
Understanding Histamine and Allergic Reactions
Histamine and Allergic Reactions are closely linked to how the immune system responds to allergens. Histamine is a nitrogenous chemical compound in the body and a part of the immune system. It becomes active when the body encounters foreign bodies or external allergens like pollen, certain foods, or animal dander, which can trigger an allergic reaction.
These allergens often enter the body through the air. Sometimes, the immune system overreacts, leading to uncomfortable symptoms.
Symptoms of Allergic Reactions
Allergic reactions can manifest as hay fever, runny nose, itchy and watery eyes, skin rashes, dermatitis, flushing, and sneezing. The fluid from the eyes and nose comes from blood plasma, containing proteins and antibodies that fight off infections.
This internal defense can cause symptoms like skin rashes, inflammation, redness, and fatigue due to the body’s heightened activity. Wheezing can occur as the bronchial tubes in the lungs swell.
The Role of Cortisol in Histamine Response

As histamine is released, the body’s stress hormone, cortisol, also becomes active. Cortisol helps neutralize histamine and reduce its effects.
However, if adrenal glands are fatigued and produce less cortisol due to poor sleep, chronic stress, diet, or underlying medical conditions, allergic reactions can become more severe. Insufficient cortisol means the body cannot effectively neutralize histamine, leading to its increased production and levels.
Quercetin as a Natural Antihistamine
Quercetin is a plant-based antioxidant compound that can help minimize histamine symptoms. It works by inhibiting the action of mast cells, which produce histamine.
Quercetin also directly counteracts histamine’s effects, reducing inflammation and mucus production. It can be considered a natural alternative to over-the-counter antihistamines, with no significant side effects.
Sources and Dosage of Quercetin

Quercetin can be obtained naturally from foods such as onions, apples, tomatoes, okra, and green tea, as well as leafy green vegetables, cilantro, radish leaves, and fennel.
For more severe symptoms, quercetin supplements are recommended. A dosage of 1000 mg taken once can be taken up to four times a day, for a total of 4000 mg daily, during severe episodes like coughing, congestion, rashes, or asthma.
Optimizing Quercetin Absorption
Quercetin is fat-soluble, meaning its absorption is enhanced when consumed with fat. Incorporating it into meals like bone broth with fatty meat or adding it to dishes with spinach and onions can improve its uptake by the body.
For severe allergic reactions, Vitamin D (20,000 IU per day) and Zinc (50 mg per day) supplements are also beneficial. Zinc can also be found in eggs, nuts, beef, and red meat.
FAQs About Histamine and Allergic Reactions
What is histamine and how does it cause allergic reactions?
Histamine is a chemical compound in the body that becomes active when the immune system encounters allergens such as pollen, certain foods, or animal dander. It can trigger symptoms like sneezing, runny nose, and skin rashes.
What are common symptoms of histamine and allergic reactions?
Symptoms include hay fever, itchy and watery eyes, skin rashes, dermatitis, redness, flushing, fatigue, and wheezing. These occur because the immune system releases histamine in response to allergens.
How does cortisol affect histamine and allergic reactions?
Cortisol is a stress hormone that helps neutralize histamine. When cortisol levels are low due to stress, poor sleep, or adrenal fatigue, allergic reactions may become more severe.
Can quercetin help with histamine and allergic reactions?
Yes, quercetin is a natural antioxidant that acts as a natural antihistamine. It works by reducing histamine release, inflammation, and mucus production without major side effects.
What foods are rich in quercetin?
Foods rich in quercetin include onions, apples, tomatoes, okra, leafy green vegetables, cilantro, radish leaves, fennel, and green tea.
What is the recommended dosage of quercetin for histamine and allergic reactions?
For severe symptoms, up to 4000 mg daily (1000 mg up to four times a day) may be taken. Supplements are often recommended when symptoms are intense.
How can you increase quercetin absorption?
Quercetin is fat-soluble, so it absorbs better when taken with meals containing healthy fats such as fatty meats or leafy greens cooked with oil. Pairing it with Vitamin D and Zinc can also improve its effectiveness.