What is Histamine?

Histamine: a word we've all heard a zillion times. It's also known as C5H9N3 in the science world. For a while, I've wondered about the science behind histamine and anti-histamine (allergy pills). I decided to put on my Nancy Drew pants and did a little research...

This is the full definition of histamine from Merriam Webster:

"a compound C5H9N3 especially of mammalian tissues that causes dilation of capillaries, contraction of smooth muscle, and stimulation of gastric acid secretion, that is released during allergic reactions, and that is formed by decarboxylation of histidine"

The simple definition:

"a chemical substance in the body that causes the symptoms that people experience when they are allergic to something"

So, histamine is what causes us all that pain and suffering from allergies! And it led me to this question: why is histamine in our bodies and how is it getting there when it isn't supposed to be there? So, I dug a little deeper and found out that it's all due to our immune system.

For people with allergies, our bodies are in a nutshell: confused.

Our bodies are deciding that things which aren't normally harmful to humans... ARE harmful... and they label this as a foreign invader (whether it's pollen, cats, etc) and send our immune system out on attack. This is what produces the release of histamine which sends our bodies into a tizzy as we become inflamed, stuffed up and feeling not so great. 

Here are some more symptoms of histamine release:

  • swelling
  • itching
  • eczema
  • nausea
  • irritability
  • hay fever
  • headache
  • runny nose
  • diarrhea
  • fatigue
  • anaphylaxis
  • wheezing
  • coughing
  • stomach ache

An interesting thing about histamine is that it has three different receptors that do three different things. They're called H1, H2 and H3:

  • H1 controls the reaction of capillaries and smooth muscle.
  • H2 controls gastric acid secretion and heart rate.
  • H3 is involved with the central nervous system.

For those of us having allergic reactions, these reactions are generating extra histamine. However for some people, their bodies can't deal with normal levels of histamine. This is called "histamine intolerance". The symptoms of it are very similar to those above except they're a little more on the extreme side. You can read more about that here and here.

In my research I found out something that I think will be really helpful to all of us trying to battle histamine:

There are foods that are high in histamine! So if you're already battling histamine, you should be avoiding these foods as much as possible:

  • fermented alcoholic beverages (wine, beer, champagne, etc)
  • fermented foods
  • canned foods
  • soured foods (sourcream, buttermilk)
  • smoked fish
  • shellfish
  • certain fish: anchovies, sardines, mackeral, mahi-mahi & tuna
  • vinegar
  • citrus
  • cured meats
  • aged cheese
  • walnuts
  • cashews
  • soy beans
  • chickpeas
  • peanuts
  • avocado
  • spinach
  • tomatoes
  • eggplant
  • chocolate

Another way to battle histamine, as we know it, is anti-histamine. Here's a long list of brand names courtesy of the Mayo Clinic.

How do YOU lower your histamine level?