Histamine is a chemical, known as a biogenic amine. It plays a role in several of the body’s major systems, including the immune, digestive, and neurological systems.

The body gets all the histamine it needs from its own cells, but histamine is also found in certain foods.

People who experience an allergy-like response to histamine-rich foods may have a condition known as histamine intolerance. This condition affects roughly 1 percent of the population. There may be individuals with genetic traits that increase their sensitivity to histamine.

Certain medical conditions may increase the risk of histamine intolerance. These include:

Some prescription or over-the-counter drugs may interfere with the enzyme that breaks down histamine, such as:

People with histamine intolerance may experience a wide variety of symptoms involving different systems and organs.

For some people, histamine-rich foods can trigger headaches, skin irritation, or diarrhea. Certain medications or conditions can increase the chance of histamine sensitivity.

There are no reliable tests or procedures that doctors can use to diagnose histamine intolerance. However, some medical professionals will suggest an elimination diet.

This involves removing certain foods from your diet for at least 4 weeks and slowly adding them back in, one at a time. An elimination diet can help you determine whether histamine is the problem.

Histamine levels in food are difficult to quantify.

Even in the same food product, like a piece of cheddar cheese, the histamine level can vary significantly depending on how long it’s been aged, its storage time, and whether it has any additives.

Generally, foods that have been fermented have the highest level of histamine. Fresh unprocessed foods have the lowest levels.

There’s also a theory that some foods — though not histamine-rich themselves — can trigger your cells to release histamine. These are known as histamine liberators. This theory, however, hasn’t been proven scientifically.

The following foods contain higher levels of histamine:

  • fermented dairy products, such as cheese (especially aged), yogurt, sour cream, buttermilk, and kefir
  • fermented vegetables, such as sauerkraut and kimchi
  • pickles or pickled veggies
  • kombucha
  • cured or fermented meats, such as sausages, salami, and fermented ham
  • wine, beer, alcohol, and champagne
  • fermented soy products such as tempeh, miso, soy sauce, and natto
  • fermented grains, such as sourdough bread
  • tomatoes
  • eggplant
  • spinach
  • frozen, salted, or canned fish, such as sardines and tuna
  • vinegar
  • tomato ketchup

Low-histamine diets can be extremely restrictive and can lead to malnutrition.

Histamine intolerance is poorly understood and difficult to diagnose. There’s no evidence that a low-histamine diet will improve quality of life in the long term if you don’t have a true diagnosis.

The primary benefit of a low-histamine diet is that it can serve as a diagnostic tool.

By eliminating histamine-rich foods from your diet for several weeks (under the supervision of a doctor) and then slowly adding them back in, you can learn more about your individual tolerance to foods containing histamine.

Histamine tolerance varies significantly from one person to the next. When you add histamine back into your diet, you can carefully evaluate which foods trigger uncomfortable symptoms, if any.

To eliminate histamine-rich foods and practice a lower histamine diet:

  • cook all your own meals
  • eat foods that are as close to their original form as possible
  • record everything you eat in a detailed daily food diary (be sure to include the time of day you ate each food)
  • record the times and dates of any uncomfortable symptoms for comparison
  • avoid junk food or anything highly processed (if there are numerous ingredients and the food item is ready to eat)
  • don’t be too hard on yourself as this diet is very restrictive
  • don’t plan on eating this diet for more than 4 weeks
  • eat only fresh foods that have been kept in a refrigerator
  • speak with a dietitian or a nutritionist about getting all the nutrients you need while on this diet
  • talk to your doctor about vitamin and mineral supplements (consider DAO enzyme supplements, as well as vitamin B-6, vitamin C, copper, and zinc)

Consult with a doctor before beginning a low-histamine diet.

Nutrient deficiencies can be harmful at any age, but this diet is especially dangerous for children. If you suspect your child has food allergies or sensitivities, talk to your pediatrician about an alternative treatment.

If you experience dizziness, headaches, or any other complications, you should stop this diet immediately and consult a doctor.

After you eliminate or reduce histamine in your diet for 2 to 4 weeks, you can begin slowly introducing histamine-rich foods back into your meal plan, one at a time. Talk to your doctor or nutritionist about how best to reintroduce these foods.

There’s very little scientific evidence to support the effectiveness of a low-histamine diet and it can lead to malnourishment. Generally, a low-histamine diet isn’t a long-term treatment plan for the general population. It’s helpful in the diagnosis process and can help you rule out other food intolerances.

Ultimately, you’ll need to determine your individual tolerance to different histamine-containing foods. Some medications can increase the chances of reacting to these foods.