Sesame allergies are on the rise: the hidden killer in salads and breads

The global incidence of sesame allergy has nearly tripled in the past 10 years, and the prevalence of sesame allergy in adults in my country has also increased from 0.5% in 2013 to 1.2% in 2023. And because sesame is often hidden in daily foods such as salads and breads in the form of sesame oil, sesame powder, and ingredient additives, only a dose of 1-2 sesame seeds may cause severe allergic reactions or even death. It is one of the most easily ignored food allergens today.

Last week, I went to the allergy department of the city hospital to get an allergen test report for a friend. I happened to meet Xiaoyu, a 16-year-old high school student who was helped in by her parents. Her face was so swollen that she couldn't even open her eyes and she was breathing heavily. After questioning, I found out that she bought some cold noodles at the school gate at noon, and the boss sprinkled a handful of cooked sesame seeds with Titian - she only knew that she was allergic to peanuts before, and never realized that sesame would also put her in the emergency room.

Many people may think this is an exaggeration when they hear it. Isn't it just a little bit of a joke? But what you don’t know is that sesame contains a total of 9 allergenic proteins from Ses i 1 to Ses i 9. They are extremely stable and cannot be destroyed by high-temperature cooking, frying or grinding. Even if only a few thousandths of sesame ingredients remain, it may cause allergic people to develop rashes, laryngeal edema, and anaphylactic shock. There are nearly a hundred allergic deaths caused by accidental eating of sesame in the world every year.

As for the reason for the sudden increase in sesame allergies, there is currently no unified conclusion in the academic community. Some scholars who support the "late exposure hypothesis" believe that in the past decade or so, many parenting guidelines have recommended that allergy-prone infants and young children should avoid contact with highly allergenic foods such as nuts and sesame before the age of 3 years old. Instead, they have missed the window period for establishing immune tolerance. When children grow up, accidental exposure will more easily cause allergies. This is why the new version of the infant complementary food introduction guide now recommends that you can try sesame and peanut products in small amounts after the introduction of complementary foods at the age of 6 months. There are also some scholars who are more inclined to the "cross-sensitization theory." Their research data shows that nearly 70% of new sesame-allergic patients have a history of allergy to artemisia pollen or ragweed pollen. Some of the allergenic proteins of sesame are highly similar to the protein structures of these pollen, which causes people who are originally only allergic to pollen to gradually develop allergic reactions to sesame.

What’s even more troublesome is that sesame seeds are now almost “hidden” in our daily diet, and you don’t notice them at all when you eat them. Let’s talk about the cold dishes that everyone loves to eat in summer. Many businesses add a lot of sesame seeds when cooking the oil to enhance the flavor. Even if no sesame seeds are sprinkled when serving the dish, the sesame protein in the oil is enough to cause allergies. ； There are also commonly eaten toasts, bagels, and European buns. Many pre-mixed powders will add sesame powder to increase the aroma. The ingredient list may only say "grain powder" and "edible spices" without specifically labeling sesame seeds at all. ； Even the salad dressings, hot pot dips, and instant oats you buy may contain sesame ingredients. I made bagels at home last month and used a popular multigrain ready-mixed powder. I didn’t read the ingredient list carefully so I took two of them to the company as breakfast for a colleague. The colleague only had a mild sesame allergy and her mouth was swollen all afternoon after eating it. Now I’m scared to think about it.

Regarding this invisible risk, the current opinions in the industry are divided into two groups. One group calls for following the example of the European Union and the United States as soon as possible and including sesame in the list of allergens that must be compulsorily labeled on prepackaged foods to reduce the risk of accidental ingestion from the production side. ； The other group believes that the overall prevalence of sesame allergy in my country is still far lower than that of common allergens such as milk, eggs, and wheat. Mandatory labeling will significantly increase the costs of food production companies. It is better to implement voluntary allergen labeling first, and at the same time increase science popularization among consumers to let everyone first establish awareness of sesame allergy.

For us ordinary people, no matter how the policies change, it is always right to be more cautious. If you are allergic, or have had unexplained rashes, edema, coughing and wheezing, especially if you feel unwell after eating cold dishes or baked goods, it is best to go to the hospital for a specific IgE test to check whether you are allergic to sesame. If you have been diagnosed with sesame allergy, don’t be embarrassed to ask when you go out to eat. Even if the dish looks clean and does not contain any sesame, you should confirm with the waiter: “Is there any sesame or sesame oil in the seasoning?”” ； When buying prepackaged food, don’t just read the ingredient list, but also pay attention to the allergen notices in the corners of the packaging. If it says “may contain sesame” or “the production workshop also processes sesame products”, try not to touch it.

Yesterday, I browsed the Moments posted by the allergist who took Xiaoyu to hospital. He said that this week he had admitted three patients with sesame allergy caused by eating baked pastries. The youngest was only 7 years old. In fact, all said and done, this thing can be said to be scary or scary, and it can be said to be controllable or not. It is nothing more than spending an extra 30 seconds to look at the ingredient list and asking if there are any sesame seeds. It is better than having to go to the emergency room, right? After all, that little sesame seed really cannot be careless.