Histamine Intolerance

Histamine is a chemical which occurs naturally in certain foods. This is also one of the chemicals that is released in the body as part of an allergic reaction, causing the typical 'itching, sneezing, wheezing, swelling' allergy symptoms.

We all have an enzyme (Diamine oxidase) which breaks down any histamine that we absorb from a histamine-containing food, so when we eat a food which contains histamine it does not affect us. However some people have a low level of this enzyme, and when they eat too many histamine-rich foods, they may suffer 'allergy-like' symptoms such as headaches, rashes, itching, diarrhoea and vomiting or abdominal pain. This is called histamine intolerance. Some studies have also suggested links between histamine intolerance and urticaria, asthma, rhinitis, eczema and anxiety and panic attacks.

Foods that are particularly high in histamine are:-

• Red wine and beer
• Cheese, especially fermented cheeses such as Camembert, Brie, Gruyere, Cheddar, Roquefort and Parmesan.
• Brewer's yeast
• Shellfish
• Most fish, including canned fish
• Tomato (especially tinned tomato, tomato puree and ketchup)
• Spinach
• Chicken
• Pork sausage and beef sausage and ham, especially 'dried' (cured) versions.
• Chocolate
• Fermented soy products (soy sauce)
• All fermented vegetables such as sauerkraut.

It is known that some foods can cause the body to release its own histamine from the cells in the body that contain it. In certain people, eating these foods will also trigger 'allergy-like' symptoms.

These foods are:-

• Uncooked egg white
• Shellfish
• Strawberries
• Tomatoes
• Fish
• Chocolate
• Pineapple
• Alcohol

It should be noted that allergy tests for these foods (skin tests or blood tests) will be negative - the cause is histamine intolerance, not food allergy.

Diagnosis of histamine intolerance is usually made by putting the patient on a low-histamine diet for a couple of weeks, and seeing if their symptoms clear up (see next pages). Some blood tests can be helpful (measuring levels of histamine or the level of the enzyme that normally breaks histamine down), but these are not widely available and are rarely used.

Treatment consists of avoiding histamine-rich foods. Taking a regular antihistamine is often helpful.

Supplements replacing the missing enzyme are becoming available, but it is too soon to know whether they will be of any real help.

Updated 8/2008

Low-histamine diet (courtesy of the International Chronic Urticaria Society)

The following foods are high in histamine and should be avoided for 2-4 weeks. If symptoms improve significantly, reintroduce the avoided foods gradually; you should be able to work out your 'tolerance' level for histamine. If the avoidance does not improve your symptoms, reintroduce all foods as normal.

Meat/Poultry/Fish

• All seafood including shellfish or fish, fresh, frozen, smoked or canned
• Egg (a small quantity in a baked product such as pancakes, muffins, cakes is usually tolerated)
• Chicken
• Processed, smoked and fermented meats such as luncheon meat, sausage, salami, pepperoni 

Milk and Milk Products

• Cheese (except for cottage cheese and ricotta cheese which are allowed)
• Cheese products such as processed cheese, cheese slices, cheese spreads
• Yogurt

Note: plain ordinary milk is allowed

Fruits and Vegetables

• Orange, Grapefruit, Lemon, Lime and all other citrus fruits
• Cherries
• Strawberries, Raspberries, Cranberries and all other berries
• Apricot
• Pineapple
• Dates
• Raisins and currants
• Prunes
• Relishes, Pickles
• Spinach
• Tomatoes, Ketchup and Tomato sauces / purees / pastes
  

Food Additives

• Tartrazine and other artificial food colors
• Preservatives, esp. benzoates, sulfites and BHA, BHT

Seasonings

• Cinnamon
• Chili powder
• Cloves
• Anise
• Nutmeg
• Curry powder
• Hot paprika (cayenne)

Miscellaneous

• Fermented soy products
• Fermented food
• Tea - herbal or regular
• Chocolate, cocoa, and cola drinks
• Alcohol
• Vinegar and foods containing vinegar such as pickles, relishes, ketchup, and prepared mustard
• Liquorice

What you can eat

All fresh meats except chicken. Any vegetables not on the list above (root vegetables such as potatoes, carrots, parsnip, beetroot, sweet potatoes etc are OK, as are peas and beans), cereals such as rice, wheat, oats, corn and rye, fruits such as apples, pears and bananas (bananas in moderation only).