Sesame and Other Seeds
The distinction between tree nut and seed is not always clear. We often think of seeds as small in size - like sesame seed, sunflower seed, mustard seed, poppy seed or pumpkin seed. In fact, coconut (including the husk and inner white flesh that we eat) is also a seed, albeit a very large one! This may explain why coconut is considered to be a tree nut in USA but a seed elsewhere.
The most common type of allergy to seed is due to sesame.
Sesame seed allergy is not new (it was first reported in the 1950s), but it has become increasingly common and now is one of the top 10 causes of food allergies. Increasing consumption of sesame might explain why more and more children in the UK are developing this once rare allergy. In countries such as Israel, where sesame has been a very common food for decades, sesame allergy is very common. At this time, it is unknown exactly how often sesame allergy is outgrown or long it may take for someone to outgrow sesame seed allergy.
Other seeds have also been reported to cause allergies, including sunflower seed, mustard seed and poppy seed, although these other types of allergies are much less common than sesame.
Some people allergic to sesame are also allergic to peanut and tree nuts. It is therefore important that anyone with an allergy to seeds such as sesame is assessed by an Allergy Specialist, who can provide advice as to what foods an allergic person must avoid.
Sesame (Sesamum indicum), is also known as Benne, Gingelly, Til or Teel, Simsim and Ajonjoli on foreign products.
Sesame Seeds are extremely potent allergens capable of causing severe allergic reactions (anaphylaxis) in susceptible individuals. Sesame is becoming more common in the diet today and is used extensively in everyday foods, especially on bread and other bakery products. Products that are not intended to contain sesame may have traces of the allergen due to manufacturing or marketing practices.
Hummus, Tahini and Halvah are three very popular sesame products, which are sometimes added to other foods. Other common sources of sesame include: bakery products, biscuits, crackers, breadsticks, rice cakes, bagels, pies and muesli. Some pre-packed delicatessen and processed foods contain sesame, for example: noodles, dips, soups, sausages, samosas, processed meats, veggie burgers, chutneys, salad dressings, mixed spices, spreads and confection bars. It is an unexpected ingredient in some herbals drinks, for example Aqua Libra. Unwrapped bread products and patisserie counters may be contaminated with sesame seeds.
Note that many people with mild allergy to sesame are able to eat buns and breads coated with sesame seeds. This is because the protein causing the allergy is only released if the seed is broken and squashed, such as with the production of hummus and sesame snacks. If the seeds on buns are eaten whole, the protein is not exposed and does not cause a reaction. This is why many people with sesame allergy can eat small amounts of sesame seeds on bakery products.
Unlike other oils such as peanut oil, which is usually refined to the point where there is little or no allergenic protein left, sesame oil is made by cold-pressing sesame seeds and is not refined, so retains most of its allergenicity. It is used ‘unrefined’ in food products and as a result it contains sesame allergens which can cause reactions to those allergic to sesame seed. It resists rancidity and is extremely popular with Oriental Chefs.
Sesame oil (sesamum indicum) is also used in pharmaceutical products and cosmetics. Some allergy tested cosmetics contain sesame. Although refined sesame oil is used in these products, hypersensitive reactions (urticaria) have been reported.
Restaurant Food presents the highest risk. Peanut allergy is well recognised in the catering sector, but catering staff often do not appreciate that sesame allergy is just as serious. Sesame is often masked in restaurant foods, especially stir-fries, curries and risottos.
Oriental cooking and vegetarian foods are particularly hazardous. Many restaurants today use bought-in meals, which may not carry full ingredient lists. Another risk lies in the re-use of cooking oils, a common practice in the catering sector. Always speak with the person responsible for preparing the food.
Sesame allergy has received scant attention in the UK. Education of sesame patients and professionals caring for them is still inadequate. Negative skin and blood tests have been reported in some patients with recurrent anaphylactic reactions to sesame. The reasons for this are not known. Clearly, it is essential to view any reaction to sesame as potentially serious and those affected should seek expert medical advice.
Pharmaceuticals and Cosmetics: Sesame oil in pharmaceuticals and cosmetics has induced contact dermatitis. Surprisingly, some "Allergy Tested" cosmetics contain sesame, which may be listed as Sesamum Indicum, so be vigilant about reading labels. (Cosmetic products are now required to declare ingredients).
Reports of anaphylaxis induced by sesame are increasing. It is essential to view any reaction to sesame as potentially serious. Those affected should seek medical advice. In addition to carrying the prescribed medication, those at risk of anaphylaxis should consider wearing an Emergency Alert necklace or bracelet to alert doctors and other bystanders to their problem.