Food ingredients that may cause allergies

According to global clinical statistics, more than 90% of food allergies are caused by specific protein components in eight types of food: casein and β-lactoglobulin in dairy products, ovomucoid and ovalbumin in eggs, gliadin in wheat, 2S albumin and storage protein in peanuts and nuts, hydrophobic binding proteins in soybeans, parvalbumin in fish, and tropomyosin in crustaceans. The remaining less than 10% of allergic cases are scattered in niche ingredients such as urushiol in mango, lipid transfer protein in stone fruits (peaches, plums, and cherries), and actin in kiwi fruit.

Maybe many people have no idea about these unpronounceable names. When I accompanied a friend to get an allergen report in the allergy department (also known as the allergy department) a while ago, I happened to meet the mother of a three-year-old child. She was crying to the doctor while holding the ingredient list of a bag of ordinary toast. She said that the child had a red rash on her mouth every time she ate it. She thought it was eczema, but she didn't expect that she was allergic to gliadin in wheat. Here I would like to mention a disagreement that is still being debated in the industry: many people confuse food allergies and food intolerances. One school of thought believes that only acute reactions mediated by IgE are considered real food allergies, such as rashes and breathlessness within half an hour of eating, while those mediated by IgG, which may take a day or two to react, are intolerances and are not considered sensitization. ； However, another group of clinicians believes that chronic allergies can also cause long-term rashes, diarrhea, and headaches, and should also be included in daily diet avoidance. There is no need to stick to such a rigid definition and delay ordinary people from adjusting their diet.

My previous experience with a fitness partner is more representative. I bought whey protein isolate that was said to be completely lactose-free in order to build muscle. After drinking it three times, I got hives three times. After a checkup, I found out that he was not lactose intolerant, but allergic to β-lactoglobulin in whey. In human terms, this protein structure is extremely stable and may remain in even highly processed whey isolate. For him, even one sip is equivalent to sending a fire bomb to the immune system.

Many people think that boiled eggs will not cause allergies. In fact, the ovomucoid in egg whites is very heat-resistant and will not be completely denatured even if cooked at 100°C for 10 minutes. Many one- and two-year-old children are allergic to steamed eggs, mostly because of this ingredient. My best friend's baby was like this. My grandma used to think that the baby had poor immunity and that it would be better if he ate a few more times. As a result, the baby had diarrhea for half a month. Finally, he stopped eating eggs after checking the allergens, and he recovered within two days.

Another situation that is easily overlooked is cross-allergy. I have a friend who is allergic to birch pollen every spring and has to wear a gas mask when going out. Two years ago, after eating a freshly picked peach in the spring, his mouth swelled into a sausage in ten minutes. When I checked, I found that the lipid transfer protein in the peach has almost the same protein structure as that of birch pollen. The immune system got confused and directly beat the peach together. Similarly, people who are allergic to latex will most likely feel uncomfortable eating bananas and avocados. The same reason applies.

It is now mandatory for domestic prepackaged foods to label the eight major categories of allergenic ingredients, but there are still many voices calling for the addition of common allergens such as mango, kiwi, and stone fruits. As for the words "This product's production workshop also processes nuts and crustacean products and may contain trace amounts of allergenic ingredients" printed on many packages, many people on the Internet criticized the manufacturer for passing the blame. I worked as an assistant in the allergy-friendly food research and development team for half a year. To be honest, this label was not perfunctory - we tested it at the time. After making peanut butter on the same production line, even if it is washed three times according to the standard process, trace amounts of peanut protein can still be detected in the subsequent soda crackers. For people with severe peanut allergies, even a few milligrams may cause anaphylactic shock. This seemingly unnecessary reminder is actually a lifeline for people with high allergies.

After all, food allergies vary greatly from person to person. Some people are allergic to mangoes even if they touch the mango skin, others are okay to eat peanut butter mixed with everything, and go to the hospital after eating ice cream containing crushed peanuts. There is really no need to use other people's tolerance as a reference. If you often get rashes, diarrhea, or headaches for no apparent reason, it’s better to check for allergens and take a second look at the ingredient list and instructions when shopping. It’s better than suffering, right?