By CJ Puotinen

You may be versed in nutrition, but what do you know about histamine intolerance? If you’re like many Americans, the answer is likely not much—yet foods that contribute to this widespread condition may already have an adverse effect on your health.

Histamine is a biologically active substance that participates in 23 different physiological functions within the immune, digestive, and central nervous systems: 

• Defends against potentially harmful bacteria, viruses, and other foreign bodies
• Aids digestion by increasing hydrochloric acid secretion from cells in the stomach lining
• Helps maintain wakefulness, alertness, and reaction time

Histamine is metabolized from histidine—an amino acid required for human growth, tissue repair, and the maintenance of myelin sheaths that protect nerve cells. 

The right amount of histamine helps our bodies digest food, increase mental focus, and deliver blood and oxygen where needed to speed healing and improve health. But too much histamine can cause:

• Seasonal allergies, runny nose, throat irritation, a chronic cough, and breathing problems 
• Digestive distress: diarrhea, cramping, abdominal pain, heartburn, bloating, and flatulence 
• Flushing, heat, blushing, itching, hives, and skin rash 
• Rapid heartbeat, tachycardia, low blood pressure 
• Headaches, including migraines
• Dizziness
• Fatigue, sleep disturbances, and insomnia
• Hormone imbalances, including hypothyroid and menstrual or menopausal symptoms
• Anxiety
• Eczema
• Nausea or vomiting
• Edema, swelling of hands or feet, fluid retention, or swollen eyelids

Histamine intolerance is often confused with allergies, but allergic reactions produce antibodies while histamine imbalances do not. No one knows how many suffer from histamine intolerance because it hasn’t been studied the way allergies have, and its symptoms vary so widely from one patient to another and even within a single patient that it’s difficult to diagnose. 

The medical literature estimates that one to five percent of people are histamine-intolerant, but health care professionals who treat the problem consider those estimates exceedingly low. Most patients with histamine intolerance symptoms visit several physicians for recurring symptoms before an accurate diagnosis is made.

Several reasons may account for the oversight in diagnoses, including lack of straightforward laboratory testing, and difficulties in linking specific foods to symptoms. Additionally, many foods that trigger histamine intolerance are highly regarded because they contain important nutrients. Most of the histamine intolerance research has taken place in Austria, Germany, and Switzerland, and while awareness of the condition is spreading to the other countries, western Europeans are more familiar with histamine intolerance than people in the rest of the world.

High-histamine Foods

High-histamine foods that can overwhelm the body include fermented sauerkraut, kimchi, aged meats, pickles, yogurt, wine, or beer, plus dried fruits, avocados, eggplant, spinach, nearly all fish and shellfish, most cheese, and refrigerated leftovers. 

Some foods trigger release of the body’s own histamines, such as alcohol, bananas, tomatoes, wheat germ, beans, papaya, chocolate, citrus fruits, nuts, peanuts, and food dyes or additives.

Of note, some foods block or interfere with the body’s production of diamine oxidase (DAO) and histamine N-methyl transferase (HNMT)—two enzymes that break down histamines and clear them from the body. Alcohol is the main offender along with black, maté, or green tea, energy drinks, some medications, and even digestive disorders like leaky gut syndrome and inflammatory bowel disease. Your body may not produce enough DAO to counteract excessive histamines, a condition known as DAO deficiency. 

The connections between histamine intolerance and specific foods are not always obvious. Sometimes a histamine-sensitive person may feel fine after eating avocados with bacon and balsamic vinegar, while at other times the same foods trigger a dramatic headache or diarrhea attack—symptoms that may not appear until the next day. To find connections, histamine intolerance experts encourage patients to study food lists, consume as many low-histamine foods as possible while avoiding high-histamine foods, and keep a food journal documenting everything they eat and every symptom they experience. 

The term “histamine bucket” demonstrates why symptoms are unpredictable. In her book Histamine Intolerance: A Complete Guide for Health Care Professionals, medical microbiologist Janice Joneja, PhD, explains, “Think of histamine intolerance like a bucket filling up with water. Everything is fine while the water is below the top of the bucket; however, as soon as the bucket overflows, serious problems can occur.”  

Because histamines don’t expire, evaporate, or disappear on their own, they stay in the bucket unless enzymes like DAO help remove them. Whenever sufficient levels accumulate, the histamine spillover triggers reactions.

A first step in preventing symptoms is avoiding problematic foods. In 2018, the medical journal Annals of Dermatology reported on 22 adult patients with physician-diagnosed chronic urticaria, defined as frequent episodes of itching hives lasting longer than six weeks. Because 70 to 90 percent of such cases have no known cause, treatment options are limited. To test a low-histamine diet, patients avoided high-histamine foods such as fermented foods, soybean paste, red pepper paste, mayonnaise, yogurt, cheese, catchup, wine, beer, grapes, bananas, strawberries, lemons, oranges, tangerines, pineapples, tomatoes, nuts, peanuts, green tea, and chocolate. After four weeks on their low-histamine diets, the patients showed significant improvement and a reduction of plasma histamine levels. 

While food lists are helpful, they offer general guidelines and are not specific to your body’s chemistry. Keeping a food journal will help you not only document foods that generate serious symptoms but also monitor results from experimenting with foods that are regarded as safe. Factors like growing conditions, processing, and storage make a difference. An unripe fruit or vegetable doesn’t contain much histamine while a ripe one contains more and an over-ripe or rotting fruit or vegetable contains the most.

Fermentation generates histamines, so the level in packaged or canned foods depends on their processing and the degree of fermentation they experience. Animal proteins such as meat or fish are low in histamines when very fresh and high in histamines if aged, smoked, left at room temperature, or even refrigerated. 

Accordingly, histamine-intolerant patients are reminded to prepare food quickly and freeze leftovers immediately. Freezing interrupts histamine production while refrigeration merely slows it. Frying and grilling increase the histamine content of foods while boiling and baking do not. Bone broth made in an Instant Pot or pressure cooker contains fewer histamines than bone broth simmered for hours in a slow cooker. Ground meat has higher histamine levels than whole pieces. Eating protein within two hours of going to bed is likely to increase histamine levels during the night. 

Of the histamine food lists available, the most authoritative come from Europe. The Histamine Food Compatibility List published by the Swiss Interest Group Histamine Intolerance (SIGHI) rates and color-codes safe and problematic foods along with 300 food additives, preservatives, and coloring agents. The list is available at histaminintoleranz.ch. 

An Austrian study of 800 participants and their reactions to 109 foods is described in Genny Masterman’s book What HIT me? Living with Histamine Intolerance (see histamineintolerance.org.uk). These resources offer detailed introductions to histamine intolerance and a variety of treatment options.  

Histamine-restricted Diets

Most histamine-restricted diets recommend avoiding common foods:

• Seafood: fish and shellfish unless the fish is freshly caught, gutted, and eaten within one hour
• Meat: processed, smoked, or fermented meats such as luncheon meat, sausages, hot dogs, salami, smoked ham, and cured bacon. 
• Fermented dairy products: cheese and cheese products, cottage or ricotta cheese, yogurt, kefir, and buttermilk 
• Fruits, vegetables, and legumes: citrus, especially oranges and orange zest, strawberries, pineapple, all dried fruit, tomatoes, tomato sauces, ketchup, soy, soy products, spinach, red beans, eggplant, olives in brine or vinegar, pumpkin, avocado, pickles, relishes, and other foods containing vinegar, mushrooms, and sea vegetables
• Nuts: most nuts are problematic, especially walnuts, cashews, and peanuts
• Preservatives: artificial food colors and preservatives, especially tartrazine, benzoates, and sulfites
• Spices and flavorings: cinnamon, cloves, nutmeg, chili powder, anise, curry powder, and vinegar, especially aged balsamic
• Beverages: black or green tea, coffee, distilled spirits, and all wine and beer, including “dealcoholized” beer, ale, or wine. 

In general, red wines release more histamines than white. Some wineries reduce histamine content by fining, filtering, or extracting histamines with other processes, but it’s possible to find naturally produced wines that have lower-than-average histamine levels. Check with wine merchants for details.

As you study lengthy “don’t eat these” food lists, you’ll wonder whether there is anything left to eat. Low-histamine diet plans are restrictive, but they still offer variety and nutrition.  

Recommended low-histamine foods include very fresh meat, freshly caught fish, apples, peaches, gluten-free grains, and fresh vegetables other than tomatoes, avocados, spinach, and eggplant. Like apples, onions contain quercetin, an antioxidant that has antihistamine effects. Other helpful foods include pomegranates, olive oil, and omega-3 fatty acids. 

Nutritional supplements can help break down and clear histamines from the body, but the beneficial effects are short-lived and disappear as soon as food is digested. Supplements cannot cure histamine intolerance but when combined with meals, they may help prevent a histamine bucket from overflowing, or at least slow its filling. Nutritional supplements advertised as histamine blockers contain DAO (usually derived from pork kidneys) by itself or combined with quercetin, rutin, vitamin C, nettles, or other ingredients that have been shown to help clear histamines from the body.

Histamine intolerance researchers acknowledge that many affected by this condition recover after diagnosing themselves with the help of histamine intolerance study groups and organizations, but they warn that much of the information available online is inaccurate and not based on science, especially regarding products or tests that claim to treat or diagnose histamine intolerance. In What HIT Me? Masterman describes medical tests that do and don’t help histamine-intolerant patients, reliable resources that explain research in nontechnical language, and a popular app that lists not only histamines but other problem ingredients in hundreds of foods (see the Food Intolerances app by Baliza GmbH). 

Becky Campbell, ND, histamine specialist and author of The 4-Phase Histamine Reset Plan, recommends a low-histamine diet, healthy exercise routines, good sleep habits, stress-reduction techniques, detailed food diaries, and well-maintained air purifiers to help prevent histamine problems. 

The Swiss book Mast Cell Friendly and Low Histamine Cooking by Heinz Lamprecht (available at histaminintoleranz.ch) and What HIT Me? offer dozens of recipes and detailed instructions that smooth the transition to a low-histamine diet. The encouraging news is that many who have reduced their histamine reactions not only feel better and lead more active lives but in some cases are able to eventually resume eating some of their favorite foods without adverse reactions.

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CJ Puotinen is a long-time Well Being Journal contributor and lives in Montana.