April showers bring May flowers and our local flora and fauna explosion makes many of us fall victim to seasonal allergies. For some people however, allergies are not just a seasonal suffering, but can be year-round and caused by more than the usual indoor/outdoor suspects.
According to the Asthma and Allergy Foundation of America more than 50 million Americans experience various types of allergies each year. Allergies are the 6th leading cause of chronic illness in the US.
Allergies come in many forms including skin allergies, food allergies, drug allergies, latex allergies, insect allergies, and environmental allergies. Environmental allergies alone account for 5.2 million children and 19.2 million adults which accounts for just under half of those affected annually.
That leaves the other half to causes that affect us year-round. At the heart of the epidemic are little-known molecules called histamines.
What are Histamines?
Histamine is a chemical released by the basophils and mast cells components of our immune system. It is a product of the breakdown of an amino acid called histidine and is found in many of our body’s cells.
Although it is responsible for our miserable allergy symptoms, it is also very important to our body and has many functions that are vital to our overall health.
Histamine acts in the human body as a chemical messenger to our nervous system. It helps our digestive tract function the way it is supposed to and it works on our blood vessels to dilate them which is vitally important when fighting pathogens.
Histamine is involved in the regulation of many functions such as wound healing and it affects many functions such as cognition and memory and regulation of our sleep-wake cycle. Histamines can also be found in foods through the breakdown of histidine as the food ages.
The Function of Histamine in the Body
Where allergies are concerned, histamine is released by mast cells which are immune cells that originate from our bone marrow and are present in mucosal and epithelial tissues throughout our bodies.
When these mast cells detect an allergen, they release histamine along with some other chemicals into our bloodstream which causes an allergic reaction depending on what histamine receptor is involved.
A histamine receptor is found on various cells and it binds to histamine sort of like a boat docking. The boat is histamine and the dock is the receptor site.
Once docked, the histamine becomes active. There have been four identified histamine receptors:
- H1 receptors can cause vasodilation and bronchoconstriction.
- H2 receptors involve gastric acid secretion, airway mucus production, and vascular permeability.
- H3 receptors play a role in neuro-inflammatory diseases.
- H4 receptors have been shown to be involved in allergy and inflammation.
We have all heard of medications like Zyrtec, which is an H1 blocker and Pepcid which is an H2 blocker. These medications block the dock so the histamine cannot activate.
Although we do not yet have H3 blockers, they are being researched for use in neurodegenerative conditions such as Alzheimer’s disease.
H4 blockers do not yet exist but research is ongoing.
When our bodies produce histamine, a digestive enzyme is produced in our kidney’s, thymus, and the intestinal lining called Diamine Oxidase (DAO). DAO’s function is to break down the excess histamine in our bodies.
When Histamines Go Haywire
When our body overproduce histamine or is unable to break it down, the levels become elevated and cause what we call histamine intolerance. Overproduction of histamine can be caused by many factors including allergies, bacterial infections, GI bleed, or the intake of too many histamines from certain foods or too much alcohol.
When the breakdown of histamine is impaired, this is due to a genetic or acquired decreased production of Diamine Oxidase.
If a person has suffered from histamine intolerance most of their lives, they most likely have a genetic component. Most people with histamine intolerance develop it later in life and therefore it is acquired. The question then becomes, “How do our Diamine Oxidase levels get low?”
There are many culprits including alcohol use, use of certain medications, intestinal bacterial overgrowth, and eating large amounts of histamine containing foods.
The medications that may cause DAO deficiencies are NSAIDS like ibuprofen, certain antibiotics, antidepressants, and ironically antihistamines.
Foods that are very high in histamine include dried fruits, avocados, eggplant, spinach, processed meats, shellfish, aged cheeses and the list goes on.
As far as foods are concerned, there are also foods that trigger release of histamine as well as foods that block DAO production. The symptoms of histamine intolerance include headaches/migraines, sinus issues, hives, fatigue, digestive issues, anxiety, dizziness and many more.
Histamine Help With Functional Medicine
Fortunately, there are many functional medicine tools to help deal with histamine derived allergic responses and histamine intolerance with its sometimes-disabling symptoms.
Although medications and supplements are effective at managing symptoms in the short term, the functional medicine goal is always to treat the root cause and restore health.
At Kare Health and Wellness, we have tests that help us to identify histamine problems such as food allergy and sensitivity testing, treatment protocols aimed at healing the underlying cause, and skilled practitioners to guide you along your journey to wellness.