INH inhibits histamine metabolism.  Most people aren't really familiar with the role of histamines as much as they are with "anti-histamines" the drug of choice during allergy season.  But when taking INH, histamines can build in the body and enter major reaction zone when topped off with certain foods that are either histamine release triggers, or contain histamine.

What is Histamine?

Histamines are a necessary part of the body, not just for allergic responses, but also as a hormone/chemical transmitter similar to serotonin. One of Histamines roles is:
  • Regulation of water intake and drought management.  When water regulation responsibilities arise (not enough water), the immune system can be compromised.  Long term dehydration = increased histamine levels, and suppressed immune system. (Source)
Most of the time when histamine is formed, it is either stored, or rapidly inactivated.  In the body, histamine if often stored in Mast cells, which are present in higher quantities in places where injury can take place such as nose, mouth, feet, internal body surfaces and blood vessels and is released only as required.

Histamines have been scrutinized much over the last few years as scientists discover new ways that Histamines affect the body.  Many diseases are now being linked to histamine reaction such as lupis and arthritis. (More reading).  Most reactions that have been found with INH have occurred with fish and cheese.  These reactions included headache, palpitations, skin flushing, nausea, vomiting, and pruritus. (Source)

The INH Role: The body normally produces an enzyme called diaminoxidase (DAO), which breaks down histamine. If the production of this enzyme is, for one reason or another, insufficient, the intake of histamine containing food and drink can cause an increased histamine level in the blood, which causes allergy-like symptoms. (Source) Isoniazid is an inhibitor of both monoamine and diamine oxidases. (Source)This leads to a build up of histamines in the body.

Get to the Food:
Many food products contain histamine in large amounts, and if the body cannot break down this histamine sufficiently (hello INH), it crosses the intestinal wall and enters the blood stream. Here it can cause symptoms which are comparable to allergy. This is because histamine acts as a hormone, and is responsible for the allergy symptoms associated with “true allergy.” In allergic reactions, histamine is given off by certain white blood cells, which overreact to the presence of certain harmless substances in the bloodstream. (Source)

Here is a partial list of foods that can cause histamine release or are histamine-rich (built up from this nice Source):

Foods that cause histamine to be released in a MAJOR way

Egg white
Shellfish; Aged, smoked, canned fish and fish sauces. Tuna fish, mackerel, sardines, anchovy, herring, catfish, salmon.
Certain Fruits: strawberries, papayas, kiwi, pineapple, mango, tangerines, grapefruits, red prunes
Tomatoes (also histamine rich)
Chocolate, cocoa (also histamine rich),
Alcohol, particularly red wine and champagne. Also white wine and beer.

Histamine-rich foods that also cause histamine to be released

Fish, especially deep sea and teeny fish (anchovies, etc)
Canned and processed foods with MSG, sulfites, benzoates
Smoked and processed meats such as salami, ham, bratwurst and bacon
Yeast extract & yeast
Bread and confectionery made with yeast
Fermented Beverages: Wines, Beer, Vermouth
Fermented Condiments: soy sauce, miso, red wine vinegar, balsamic vinegar, mustard, oriental sauces, sour cream

Foods that cause histamine to be released in a LESSER way

Dried fruit
Peanuts (roasted), sunflower seeds
Soybeans and soy products (tofu, etc)
Whole wheat, barley, oat, rye
Seaweed, spirulina
Canned and processed foods with MSG flavor enhancer or preservatives such as sulfites, benzoates and parabens
Certain Fruits: bananas

Histamine-rich foods

Cheeses, especially aged or molded ones such as bleu cheese
Cultured dairy products such as yogurt
Avocados, Spinach, Eggplant, some canned vegetables and some commercially prepared salads (check ingredients-tomatoes?)
Legumes, especially soy and roasted peanuts
Jams and Preserves
Coffee, black tea
Fermented Foods: Sauerkraut, Sour Cream, Vinegar, Ciders

Reducing Histamine: (Source)
  • Eliminate histamine-rich foods. Kind of goes without saying...
  • Increase your anti-oxidants.  
  • WATER, WATER, WATER - water is a natural anti-histamine


For more information on a histamine-free diet, see this chart of foods.

Interested in a Low-Histamine diet?  Here's another great chart of foods.
Images: Allergy Poster, Mast Cells

DISCLAIMER:  I am not a medical professional.  All information on this page is credited to its source; please feel free to review sources and come to your own conclusions! 

On This Page:
What is Histamine
The INH Role
Food and Histamine
Reducing Histamine Levels