Histamine’s action, accomplished via histamine receptors, encompasses:
- accelerates heart rate
- smooth muscle contraction
- increases gastric acid secretion
- capillary dilation ~ increases permeability & lowers blood pressure
There are two types of histamine receptors that actually mediate these actions:
- H1 receptors ~ contraction of smooth muscle & capillary dilation
- H2 receptors ~ accelerates heart rate & promotes gastric acid secretion
H3 receptors are believed to regulate neuron’s release of histamine and other neurotransmitters.
Because of the increased capillary dilation and permeability action caused by histamines, it can produce symptoms of:
In addition to allergy symptoms, histamine’s action of contracting smooth muscles is a major cause for asthma’s airways constriction. As a consequence, you’ll feel shortness of breath. And complete closure creates a life in peril health scenario.
Besides allergies and asthma, histamines are thought to be associated or trigger various other health conditions, like:
- chronic hives
- Crohn’s disease
- cluster headache
- interstitial cystitis
- urticaria pigmentosa
- allergic conjunctivitis
Histamine intolerance differs from an allergic reaction in that the action is caused by high levels of naturally occurring histamine in food (biogenic amines) rather than the responsive production by your body. The basis of this intolerance is low levels of the enzymes required to metabolize histamine.
- migraine headaches
- digestive issues ~ diarrhea, constipation, bloating, abdominal pain
Some foods high in histamine, thus shouldn’t be part of your diet if you suffer histamine intolerance, are:
- aged cheese
Also, you should avoid citrus fruits because they can release mast cell bound histamines. And alcohol because it can make one of the enzymes that metabolizes histamines less effective.
A histamine involved immune response to allergens that are not dangerous to you equates to living an annoying existence. Antihistamine treatment allows you to be more comfortable by counteracting this immunological error.
For those with histamine intolerance, a complementary treatment of vitamin C and vitamin B6 might help because they stimulate histamine metabolizing enzyme activity.