Histamine Intolerance: What you thought was an allergy is actually food poisoning

Most likely, you are not allergic, but have food poisoning caused by histamine intolerance.

I just received a 26-year-old female patient last week. She chased me and asked me why she would get wheezes all over her body whenever she ate Japanese food at the self-service store. She was not allergic to salmon and sweet shrimps when tested individually for allergens. She even ate freshly killed sashimi at home without any problems. However, she got infected as soon as she went to the self-service store. Finally, the serum histamine level was measured and it was found that her histamine level after eating the buffet was 4 times the normal value. To put it bluntly, she had eaten too much histamine and the body could not break it down, so she was "poisoned".

Many people confuse this with food allergies, but they are completely different. Ordinary food allergy is a "misjudgment" of the immune system. IgE antibodies focus on the originally harmless food ingredients and attack crazily. Even if you take a bite of oysters that are so fresh that they are still jumping, you will have an attack. ； But histamine intolerance is not an immune problem at all. You can think of the diamine oxidase (DAO) in your body as a "sanitation worker" who specializes in sweeping away histamine. A small amount of histamine usually comes in and is eliminated directly. If you eat too many high histamine foods at once, or your DAO enzyme activity is not enough - - For example, if you are born with low enzyme activity, drinking alcohol or taking certain antihistamines inhibits enzyme activity, and there are not enough sanitation workers, excess histamine will enter the blood circulation and cause symptoms that are almost identical to allergies: rash, edema, abdominal pain, nasal congestion, headache, and even difficulty breathing in severe cases.

Interestingly, there is still a heated debate in the academic community about whether histamine intolerance is an independent disease. Some allergists think this is a "pseudo-concept". Anyway, it is ultimately a reaction caused by elevated histamine, and it is not bad to treat it if it falls under the category of allergies. ； However, most doctors engaged in clinical nutrition do not agree with this statement - after all, the triggers are completely different, and the response plans are even different. It would be somewhat unfair to treat patients as a common allergy and ask them to avoid seafood for the rest of their lives.

Don’t think this is far away from you. Many of the things you usually eat are histamine-rich. For example, leftover spinach that has been stored in the refrigerator for two days, cured fish and bacon that has been pickled for half a month, blue cheese that has been fermented for several years, red wine that has been stored in the wine cabinet for three days after being opened, and dead shrimps and crabs that have been left in the summer market for an afternoon. As long as it is fermented, stored for a long time, and stale, the histamine content of animal and plant foods cannot be low. I have a friend who thought he was allergic to mangoes and struggled with it for several years. Later, he discovered that every time he ate ripe mangoes that were almost soft, he would switch to freshly picked hard mangoes, and there was no problem at all.

As for how to tell whether you are truly allergic or intolerant to histamine, it’s actually not that complicated. If you are really allergic, it doesn’t matter if the food is new or not, or if you eat more or less, it will happen as soon as you touch it. ； Histamine intolerance usually depends on the amount of food on the plate. It’s okay to eat less fresh food, but it’s okay to eat too much stale food, and the food that causes the attack is often not fixed. You may be affected by eating seafood today, but you may feel uncomfortable drinking red wine tomorrow. Of course, there are a few cases where it is difficult to distinguish, so it is best to do a histamine challenge test, which is much more accurate than ordinary allergen testing.

What if you really get tricked? There are currently two mainstream response methods. One is more radical and requires you to completely abstain from high-histamine foods for 3 to 6 months, and then slowly add them back when DAO enzyme activity recovers. ； The other group is more relaxed. Try to choose fresh food when eating, avoid eating leftovers, and just take DAO enzyme supplements in advance before eating high histamine foods. Many friends who practice traditional Chinese medicine even say that this is essentially due to weak spleen and stomach transportation. Eating spleen-strengthening ingredients, such as yam and poria, can slowly improve the activity of DAO enzyme. I have had several patients try it myself, and the feedback is indeed pretty good.

Of course, don’t be too careless. Although most histamine intolerance is mild and will go away on its own within a few hours, there are also very serious cases that can cause shock. If you have difficulty breathing or throat edema, don’t bear it and go to the hospital quickly. To put it bluntly, many times we easily attribute our discomfort to "allergies". In fact, it may just be that the food we eat is not fresh enough, or the body temporarily "goes on strike" and doesn't want to work. If you understand the reason, there is no need to give up a lot of delicious food for no reason, right?