What Is a Low-Histamine Diet?

A low-histamine diet can be suggested for people who have histamine intolerance. Histamine is a chemical released by mast cells in the immune system when the body encounters an allergen, which causes an allergic reaction.

Histamine intolerance, otherwise referred to as enteral histaminosis, is a rare condition that is estimated to affect about 1% of the population. It is very hard to diagnose and is often characterized by symptoms such as itching, hives, sneezing, watery eyes, asthma, headaches, abdominal pain, diarrhea, tachycardia, and hypotension.

Ingesting a large quantity of foods high in histamine can trigger this response, but figuring out which foods triggered the response can be complicated.

Once food allergies have been ruled out, people can try a low-histamine diet. This type of diet is very restrictive and should not be followed for the long term. In addition, people following a low-histamine diet should be seen by a registered dietitian or nutritionist to make sure they are receiving adequate nutrition.

Benefits

There aren’t many studies examining the benefits of a low-histamine diet, likely due to the difficulty of following a low-histamine diet and the complexity of diagnosing histamine intolerance.

A small study conducted in Italy in 2016 found that, when people restricted their intake of histamine-provoking foods, their symptoms improved. These people did not have food allergies or other gastrointestinal diseases.

There are many limitations in examining the role of histamine in the diet, and most of the time, individual cases need to be examined to determine the actual source of the intolerance. Part of the reason for this is because it’s not possible to avoid histamine altogether—exposure to histamine goes beyond diet.

Additionally, because some people are more sensitive to histamine, a dose-dependent response is plausible (meaning that the response may only occur after certain exposure threshold).

This makes following an elimination diet (where certain foods are avoided and then added back in at specific times) especially important. Keeping a food journal for a few weeks to tracks symptoms is also important in discovering the trigger foods.

How It Works

If food allergies and other gastrointestinal diseases such as celiac disease have been ruled out, your physician may try to determine if you are histamine intolerant.

To do so, they may ask you to take a skin prick test (which can be unreliable) or measure your blood to test your diamine oxidase activity (DOA), the main enzyme involved in the metabolism of histamine. Oftentimes, people with histamine intolerance have an imbalance of histamine due to a combination of too much histamine and lack of DOA.

If you are histamine intolerant, you may be told to follow a low-histamine diet. Because everyone responds to histamine differently, an individualized meal plan should be created.

Most of the time, you will start slowly by taking out high-histamine foods and logging symptoms. If you find that your symptoms have improved after removing a trigger food, you can omit that food temporarily and attempt to add it back into your diet in about a month.

The rate at which you eliminate and add foods back in will be determined by your tolerance and symptoms.

A 2018 study in the Journal of Dermatology reported that people with severe histamine intolerance with urticaria (hives) can benefit significantly from a histamine-free diet. According to the researchers, after just four weeks, the diet helped reduce the severity of urticaria and, in some cases, led to the complete resolution of symptoms.

What To Eat and Avoid

Eating a diet rich in whole, non-processed foods will be important. Foods that are very ripe, aged, fermented, or soured should also be avoided. Certain fruits and vegetables can induce a histamine response, too.

Flavonoid-rich foods like berries, carob, citrus, dark chocolate, kale, onions, red cabbage, red wine, soy, and tea actually inhibit the production of histamine and have a protective effect. This is especially true of a flavonoid called quercetin found in blueberries, black tea, and kale.

In addition, the way that you cook can increase or decrease your risk of histamine intolerance. For instance, the longer a food is left out, the more histamine will be produced. Plan to cook your meat or fish right away. Moreover, steaming or braising meat or seafood produces far less histamine than grilling.

Some people may also be advised to supplement with B vitamins, calcium, copper, zinc, and other micronutrients. Research suggests that a low intake of key micronutrients is linked to an increased risk of histamine intolerance.

Considerations

While limited data have suggested that following a low-histamine diet can reduce the symptoms of histamine intolerance, more research needs to be done in this area. Keep in mind that because this diet is somewhat restrictive, it is not meant for everyone.

General Nutrition

Overall, if done right, this diet can be a healthy one. But it important to ensure that you are eating a variety of fruit, vegetables, healthy fats, and protein.

Because one of the main focuses of the diet is the elimination of foods, people can fall into the trap of eating too much of one type of food and not enough of another. To avoid this, meet with a registered dietitian who can help you select a healthy variety of foods.

Practicality

The diet is hard to sustain as you really cannot eat anything processed, packaged, canned, or pre-prepared. Many people rely on the convenience of these foods, particularly they have a busy job or are managing a family. Whole foods can also be expensive.

Keep in mind that, most of the time, the diet is used temporarily until your symptoms are better managed. To reduce costs, buy local and seasonal foods whenever possible.

Other Diets

A low-histamine diet is one approach to overcoming histamine intolerance, but there are others that may help. Among them, a low-FODMAP diet was reported to help reduce the amount of histamine produced by the gut, according to a 2017 study in the Journal of the Academy of Nutrition and Dietetics.

FODMAP—which stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols—are short-chain carbohydrates that resist digestion, including certain fruits that high in fructose, dairy products that are high in lactose, and cereal grains that are high in fructans.

A low-FODMAP diet is frequently used to treat irritable bowel syndrome (IBS) but may help some people with histamine intolerance, particularly if they experience severe diarrhea.

A Word From Verywell

A low-histamine diet has been shown to help improve symptoms of histamine intolerance, which can produce allergy-related symptoms such as sneezing, headaches, and itchy skin.

As much as you may want to self-treat your symptoms with diet, it is still wise to speak with your doctor before starting. While you may assume that you have histamine intolerance, there may be other causes for your condition, such as celiac disease, lactose intolerance, gallbladder problems, and others.