Red wine, chocolate, cheese, strawberries, avocado.
These may sound like your favorite foods, but for some, they have a more insidious side. For those people, these foods and others like them result in allergy-type symptoms like:
How could this be? A natural compound called histamine may be to blame. And that’s the hint for what is histamine intolerance.
Histamine is a natural chemical produced in the body. When there’s an injury or an allergic or inflammatory reaction, histamine is released in the body by mast cells, a type of white blood cell. The bacteria in our gut also produce histamine and that is why they are so critical to our immune health.
When it’s on immune duty, histamine works by helping cell walls become more porous, so that chemicals needed to fight the invader can move about freely and do their job efficiently. If you’ve ever had a bout of allergic sneezing and a runny nose, you have first-hand experience of what histamine intolerance is.
While histamine plays a huge role in the immune system, it has also been found to participate in at least 22 other physiological functions in the body to date. It plays a key role in digestion, by helping to stimulate and regulate stomach acid production. As a neurotransmitter, it relays important messages between the body and brain, too. During stressful times, it acts as a vasodilator—meaning it expands our blood vessels—to bring down blood pressure. As you can see, it’s essential for our health and survival.
And yet, the body keeps a tight watch on the amount of histamine floating around. When it’s not needed, it is either safely “stored away” or rapidly broken down, so the body can go back to being non-allergic and non-inflamed—to a more peaceful state.
Remember: Foods contain histamine too. So when the total amount of histamine in our body—the sum of what is produced internally and what is obtained from foods—gets to be more than what our body can handle, the histamine bucket “overflows,” and we experience the symptoms of histamine intolerance.
When this overflow happens will vary from person to person.
Some lucky people can eat lots of histamine-containing foods and never have an issue because their body has no problem breaking it down. It could also be that their gut bacteria produce low levels of histamine, so they are safe.
Whereas others can eat only small amounts and still have a problem because they lack the necessary enzymes (called diamine oxidase and n-methyltransferase) to break the histamine down. Histamine reactions are also possible because their body is already producing too much histamine from gut bacteria, overall inflammation, or stress, so even a little more from food can tip them over.
Most of us are quite surprised when we have a reaction to food. “Why me?” “Why now?” are often asked questions.
There are several likely reasons, and many times, they overlap. It ranges from SIBO (small intestinal bacterial overgrowth), gut dysbiosis (meaning too many bad bacteria and not enough good ones in your gut), inflammation, genuine allergies, stress, overuse of medications, etc.
Our gut is supposed to degrade histamine using an enzyme called diamine oxidase, or DAO. If this doesn’t happen, the histamine gets shuttled to the liver and other areas, where histamine then has to be processed.
Some people may have low DAO from birth, whereas others may develop an issue with it after a lifetime of high-carbohydrate processed foods—a diet that can throw off the gut bacteria in such a way that there are too many histamine-producing bacterial strains, and not enough histamine-degrading strains.
The symptoms of histamine intolerance are easy to spot and there are specific foods you can avoid, to help yourself.