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 very 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 a 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 long-term. In addition, people following a low-histamine diet should be seen by a registered dietitian or nutrition professional to make sure they are receiving adequate nutrition.

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 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. 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. This makes following a rotation diet, where certain foods are avoided and then added back in at specific times is important. Keeping a food journal for a few weeks and tracking symptoms is also important in discovering the trigger foods.

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 often 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 a about a month.

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

Sometimes you will need to incorporate certain supplements and in some cases medications, such as an antihistamine, to improve symptoms. This will be discussed with your medical professionals. Some people will also need to supplement with B vitamins, calcium, copper, zinc, and other micronutrients.

Researchers suggest, “A histamine-free diet, if necessary, supported by antihistamines or the substitution of DOA, leads to an improvement of symptoms.” 

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

Fresh meat and fish: The longer a food is left out (never eat spoiled foods) or the more it is processed, the more histamine will be produced. Plan to cook your meat or fish right away and purchase wild or organic, pasture-raised when possible.

Starchy vegetables: Starchy vegetable such as sweet potatoes, yams, and butternut squash are rich in vitamin A, C, and other antioxidants. They are wholesome, fiber-rich, healthy food choices that can keep you full and replace processed grains.

Carob: Carob is packed with antioxidants and is a caffeine-free alternative to chocolate. It is also gluten-free and contains bioactive compounds such as dietary fiber, polyphenols, flavonoids, cyclitols, (like d-pinitol) and tannins. These compounds have been associated with a variety of health benefits including glycemic (blood sugar) control, cholesterol reduction, anticancer effects, and many more. It can be used in homemade baked goods and smoothies.

Fresh herbs: Fresh herbs can add flavor and nutrition to any meal without added calories and fat. They can spice up any boring protein, vegetable, or salad and are a wonderful and colorful addition to any meal plan. You can buy a potted herb plant and keep them at home if you prefer not to waste fresh herbs.

Nut-based milk: Fortified with calcium and vitamin D, nut-based milks are lower in calories and saturated fat than some cow's milk varieties and can serve for a dairy substitute for those people following a vegan or vegetarian meal plan.

There is no set schedule or timing of meals that you need to stick to unless you are taking certain medications, in which you should discuss with your physician.

Timing will be of the essence when you eliminate and add foods into your diet. When doing this, it is recommended that you consult with a professional, such as a registered dietitian.

For example, eliminating too many foods at once or reintroducing foods too quickly can reduce the quality of your diet and skew results. Working with a professional will help you to balance out your nutrient intake and reduce stress.

Cook fresh foods as often as you can. Focus on simple meal prep and cooking methods to ease the burden of meal planning. Baking, broiling, grilling, sautéing, and steaming foods are simple cooking techniques that you can use to prepare your meals.

Modifications can be made based on histamine tolerance and sensitivity. For example, while some people may need to avoid strawberries altogether, others may be able to tolerate small amounts.

Keeping a detailed food log that describes symptoms after food ingestion will be important.

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.

Discovering trigger foods and identifying tolerable foods can help you to reduce cost and improve symptoms. You must also keep in mind, the following:

Overall, if done right, this diet can be a healthy one. But one must make sure that they are eating a variety of fruit, vegetables, healthy fats, and protein.

Because one of the main focuses is on eliminating foods, people can fall into the trap of focusing on that and eating the same things daily. To ensure adequate nutrition, it’s important to meet with a registered dietitian. Some people may need additional supplements, too.

This diet is hard to sustain as you really cannot eat anything processed, packaged, canned, or pre-prepared. Most of the time, this diet is used temporarily until symptoms are managed and trigger foods are slowly added back in.

Including a wide variety of nutrient-dense whole foods is safe when done properly. Guidance is always recommended as meal plans should be individualized. As previously mentioned, it is advised to meet with a registered dietitian to ensure all your nutrition needs are being met.

For those people who like to cook and prepare foods at home, this diet may not seem too difficult. On the other hand, if you eat on-the-go regularly this diet can be particularly challenging due to its lack of flexibility, especially during the elimination phase.

Whole foods, such as fruits and vegetables, fresh meat and fish, can be expensive. Try to buy local and seasonal when possible to reduce cost.

A study found that a low-FODMAP diet reduced the histamine produced by the microbiome, which also may contribute to the reduction in pain experienced by irritable bowel syndrome (IBS) patients.

A low-FODMAP diet eliminates or reduces certain types of short-chain carbohydrates found naturally in many foods that we eat. These types of carbohydrates may be poorly absorbed in the intestine, draw extra water into the intestine, and are rapidly fermented by bacteria in the gut.

This type of eating plan also depends on an individual’s tolerance and the quantity of food that is consumed. FODMAP stands for Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.

A low-histamine diet has been shown to help improve symptoms of histamine intolerance, which can produce allergy-related symptoms such as sneezing, headaches, itchy skin, etc. Understanding histamine intolerance and diet is complex, as many individuals have differing levels of histamine intolerance.

It’s important for anyone looking to follow this type of eating plan to meet with a registered dietitian to ensure adequate nutrition: both macro and micronutrients. Because the focus is on eliminating offending foods, understanding which types of foods you need to eat to avoid nutrient deficiencies will be important. Sometimes people with histamine intolerance will also need additional supplements, and/or medications to relieve symptoms.

More research needs to be done in this area to better understand histamine intolerance and how diet plays a role in reducing symptoms.