Heavy Metals, Mast Cell Activation, and Histamine Intolerance

Updated: Jan 24

This article explains how over-exposure to heavy metals can lead to or exacerbate dysfunction in mast cell activation, which in turn impacts histamine levels in the body.


Overview of Mast Cells


If you struggle with health issues related to histamine intolerance and would like to find ways to naturally lower histamine levels, then one important piece of the puzzle to look at is mast cell activation.

Mast cells are a type of white blood cell found in tissues throughout the body such as the nervous system, respiratory airways, skin, and the lining of the gut. You can find a detailed overview of mast cells in this article.

Mast cells play a key role in the body’s natural immune response to infections, allergens, and other substances that the body perceives as foreign or toxic. Part of this process, mast cell degranulation, is the release of inflammatory agents, or ‘mediators.’ Mast cell mediators, including histamine, serve as chemical signals to other cells, tissues, and organs to coordinate the protective response to foreign invaders.


Mast Cells and Histamine Intolerance


There are several possible root causes of excess histamine in the body. Excess histamine can come from external sources including food and drink, and when released by mast cells that may be over-activated.

While mast cells play a normal role in the body’s immune system, over-functioning can be problematic; this is referred to as Mast Cell Activation Syndrome (1). If the body is continuously exposed to toxins or other substances that it perceives as threats, the mast cells create a chronic inflammatory response through the release of several different mediators, including histamine.

Histamine intolerance may eventually occur when levels of the chemical rise faster than the body can break it down and eliminate it. This increased histamine may affect multiple organs and systems in the body and manifest with different symptoms, such as rashes and hives, nasal congestion, headaches, brain fog, nausea, and indigestion. A more comprehensive explanation of histamine intolerance can be found here.


Heavy Metals and Mast Cell Activation


There are both food and non-food triggers of increased mast cell activation. Some of the non-food activators include:

  • Mold exposure

  • Lyme disease

  • Certain medications and drugs

  • Viral, bacterial, and fungal infections

  • Stress

  • Physical exertion

  • Chemicals and fragrances in household and personal products


In addition, heavy metal toxicity and/or burden is sometimes an underlying cause of mast cell activation.

Substances classified as ‘heavy metals’ include aluminum, mercury, arsenic, lead, copper, nickel, iron, and cadmium. They are naturally occurring elements, and in fact some of them are necessary (in small quantities) to maintain our health.

However, both acute and chronic exposure to heavy metals can contribute to illness or disrupt normal physical functioning, such as by triggering mast cell activation.

For example, some scientific research hypothesizes that “mercury’s activation of mast cell inflammatory mediator release may enhance allergic reactions” (2 and 3).

Other research found that three metals in particular (mercury, gold, and silver) may play a role in autoimmune disorders by modulating mast cell activity (4).


Identifying Common Sources of Heavy Metal Exposure


Exposure to heavy metals can occur through a variety of different situations, including:

  • Lead paint dust in older homes (built before 1978)

  • Industrial manufacturing/occupational exposure

  • Air pollution

  • Water contamination (from old pipes or groundwater contamination from chemicals like herbicides, insecticides, and pesticides)

  • Unsafe coatings in cookware and food containers

  • Mercury fillings from dental work

  • Cigarette smoke

  • Fish, seafood, and algae containing high levels of mercury

  • Some cosmetics and hair dyes

  • Certain medications and herbal remedies

The level of toxicity, or negative impact on your health, depends on the metal involved and the degree and length of exposure (acute or chronic). While severe heavy metal poisoning is rare, experiencing health concerns resulting from a lower level of toxicity and/or burden is more common.


Diagnosing and Addressing Heavy Metal Toxicity and/or Burden in Relation to Histamine Intolerance


In conclusion, heavy metal toxicity or exposure can contribute to mast cell disorders, which in turn can be a root cause of histamine intolerance.

If you are experiencing histamine intolerance and suspect that you have been exposed to heavy metals, then it is important to take steps to address the issue.

The first course of action is to identify and remove or distance yourself from the source of exposure.

Your physician can then evaluate your situation with heavy metals blood testing, for lead and mercury for example, or for arsenic in a random urine. These methods identify more recent exposure only.

Oftentimes it is advantageous to look for body burden of heavy metals, not acute toxicity, as would occur with chronic low grade exposure and gradual accumulation over many years.

These historical exposures can set off mast cell activation also, and are much more common than medical providers and people realize. A functional medicine practitioner may be able to offer different testing options, but these would be considered less traditional methods of evaluation by today’s medical standards. Removal of the metals has its own challenges.

For more personalized guidance, request a functional medicine consultation with Dr. John Gannage, MD.




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