Histamine Intolerance

What is Histamine Intolerance?

Histamine intolerance occurs when the body is unable to adequately process the level of histamine present in the body. When DAO levels are low or its activity is inhibited, signs of excess histamine can appear.

Histamine is a powerful compound that is essential to our health. Excess histamine, however, can cause discomfort and distress. Those who are histamine sensitive or histamine intolerant experience allergy-like symptoms in response to excess histamine consumed in foods, triggered by foods, or released in response to environmental factors. In rare cases, excess histamine is produced to excess by the body’s own mast cells (see Histamine and Mast Cells).

Common signs of histamine sensitivity or intolerance include flushing of the skin, rash, itching (esp. eyes, ears, nose), acute temporary rhinitis (sneezing, stuffy or runny nose), red/watery eyes, digestive disturbances and diarrhea. Less common signs include racing heart, chest pain, headache and dizziness.

Who is affected?

Experts suggest that about one percent of the population is histamine intolerant, while upwards of five percent experience occasional, transient histamine sensitivity. Evidence suggests that women may be more prone to histamine intolerance than men, as histamine levels are elevated during menstruation. Age also appears to be a factor. As we age, changes in the digestive environment can leave us deficient in the enzyme that breaks down gastric histamine (see What is DAO?) and therefore more vulnerable to histamine reactions. Prescription medications can also interfere with DAO enzyme activity, diminishing our ability to break down histamine, while simultaneously triggering the release of more histamine (see DAO Modulators).

Most people who experience signs of histamine intolerance or sensitivity exhibit mild to moderate symptoms that can be effectively managed by dietary modification and DAO supplementation.

Beyond Intolerance

The impact of histamine can be seen in ways that go well beyond the relatively minor symptoms of histamine intolerance. For instance, there is strong evidence to suggest that migraine and cluster headache are mediated by histamine. Histamine can increase heart rate and cause blood pressure to drop, which can produce feelings of anxiety and induce panic attacks. Some evidence even suggests that histamine may play a role in schizophrenia. Emerging research is investigating histamine’s role in multiple sclerosis (MS) and other neuromuscular disorders. Research into histamine’s far-reaching influence continues to provide scientists with new insights and opportunities for understanding and addressing some of today’s most vexing medical challenges.