Key facts about histamine intolerance

Histamine is a protein that is a biogenic amine – biological active substances that carry out a range of important tasks in the body. For example, it acts as a neurotransmitter during an allergic reaction and controls the sleep-wake cycle, production of stomach acid and blood pressure.

What causes histamine intolerance?

We still can’t explain what exactly causes a histamine intolerance. The assumption is that there is an imbalance between histamine and the impaired activity of the enzymes diamine oxidase (DAO) and histamine N-methyltransferase (HNMT), which break down histamines.

Normally, the enzyme diamine oxidase (DAO) breaks down surplus histamine in the body. If this enzyme isn’t working properly, or if there is too little of it, a histamine intolerance can occur. In this case, just a small amount of histamine will cause an allergic reaction.

What are the symptoms of a histamine intolerance?

The signs of a histamine intolerance primarily occur during and after eating. Possible symptoms include:

• Sudden reddening of the skin
• Itching
• Digestive problems such as stomach ache, diarrhoea, nausea and vomiting
• Dizziness and a rapid heartbeat
• Headache or migraine
• Red eyes
• Swollen lips
• For women: period problems, runny nose, sniffles

Coming into contact with other allergens at the same time, such as pollen, can make the symptoms worse.

How is a histamine intolerance diagnosed?

There are no specific tests for diagnosing a histamine intolerance. Blood and urine tests are not conclusive enough.

First, the doctor rules out any other food allergy or intolerance, such as lactose intolerance, coeliac disease or fructose malabsorption. A food and symptom diary can help with making the diagnosis. In the next step, those affected try a low-histamine diet, under the guidance of a medical professional. If the symptoms get better during this period, this points to a histamine intolerance.

How is a histamine intolerance treated?

It’s important to find out which foods actually lead to problems. Those affected start gradually re-adding specific foods into their diet. This way, they can find out which foods to avoid in the future.

Shortly before eating, it can also help to take the enzyme diamine oxidase in the form of tablets. Your body can use this to break down more histamine. For acute complaints, antihistamines can help alleviate symptoms.

Please note: treatment should always be carried out in consultation with a doctor.

Foods high in histamine

There are various factors that influence the level of histamine in food. Generally speaking, food that is brewed, fermented or ripens contains more histamine. These foods often contain alcohol, vinegar, yeast and bacteria. Here are a few examples of foods with especially high levels of histamine:

• Sausages
• Canned fish
• Seafood
• Hard, soft and processed cheese
• Pickled cabbage
• Spinach
• Tomatoes
• Avocados
• Aubergine
• Ready meals
• Wine

Food that is kept warm or warmed up again often contains a high level of histamine.

Foods that release histamine

It’s not just food containing a high level of histamine that can cause problems; foods which release histamine in the body also cause issues. These include citrus fruits, strawberries and chocolate. Because the enzyme diamine oxidase is supposed to break down other biogenic amines as well as histamine, pineapples, bananas, raspberries, oranges, kiwi, peanuts and other legumes can also lead to complaints. This is because they all contain different biogenic amines.

Foods low in histamine

Above all, fresh and unprocessed foods contain little histamine. Food that can be well tolerated includes:

• Fresh, unprocessed or frozen meat
• Fresh, unprocessed or frozen fish
• Cream cheese
• Cottage cheese
• Quark
• All types of vegetables and fruits that are not included on the lists of foods with high levels of histamine and foods that release histamine