For people who aren’t allergic, kiwi is one of those perfect foods: each one packs in as much potassium as a banana, more than the recommended daily dose of vitamin C – even more than an orange – as well as high levels of beta-carotene. It’s also rich in vitamin A and E, and its seeds are rich in alpha-linoleic acid, an omega-3 essential fatty acid. They’re high in fibre and have antioxidant properties, so are considered great cancer fighters.

How kiwi fruit allergies work

For all its benefits, however, the fruit can be extremely problematic for those who develop allergies to it. Most reactions are limited to itching and inflammation in the mouth and throat (this is usually linked with oral allergy syndrome), but others can experience more serious symptoms, including abdominal pain, vomiting, difficulty breathing, and in very rare cases, anaphylactic shock and death.

Part of the reason why kiwi has become such a prevalent allergen is that it cross-reacts with many other foods and substances, including birch pollen, avocado, banana, rye grain and hazelnuts, meaning the allergens share similar properties and can react the same way in the body.

It can also spell trouble for people with sensitivities to latex – which is common among health care workers – because while the substances seem fundamentally different, they share common epitopes, so the immune system sees them as the same thing.

How common are kiwi allergies?

Amazingly, kiwi first arrived on North American shores just 50 years ago, in 1962, and kiwi allergy was first reported fairly recently, in 1981. But since that time, kiwi allergies have become one of the most common allergies in Europe, with one study finding that four percent of allergic kids tested positive, and another showing that nearly half of food allergic patients in Sweden and Denmark reported reactions to the fruit.

Some researchers suspect that there is a geographic component at play, and that where there is more birch, there’s likely to be more kiwi allergy. The numbers have also shown a steady increase in North America.

But while people with latex and birch pollen allergies are at elevated risk for kiwi allergy, they shouldn’t eliminate the fruit from their diets unless they experience an adverse reaction – and if they do, they should talk it over with their allergist.

Related:

• Oral allergy syndrome: When raw fruit is forbidden
• Why do pollens and foods cross-react?
• How John Grisham solved his allergy mystery

Health Canada also developed criteria with which it can assess new potential priority allergens in the future. “That is important because that now says there’s a standard to follow,” says Marilyn Allen, a food allergy consultant to Health Canada and Anaphylaxis Canada.

The criteria say that when evaluating a potential priority allergen, Health Canada will examine the severity of reactions to a food, the data available on the prevalence of allergic reactions to it, as well as the level of exposure to the food in Canada. Staff will also research what other countries are including on their priority allergen lists.

The addition of mustard to the allergy list is a good example of the process. That allergy isn’t particularly widespread, but reactions that have occurred have been severe, and mustard is used in many products in Canada and is easily hidden behind words like “spice,” Allen says

The move to include mustard on the priority list will help people with mustard allergy and their families identify what foods are safe to eat. “It will make our lives easier in terms of labeling,” says Julie Mototsune. She’s had to avoid everything from soups to potato chips to prepared meats because of her 7-year-old’s mustard allergy.

Health Canada expects the regulations to become final by the end of 2010, at which point food manufacturers will have an 18-month implementation period.

Life is about to change, but rest assured, food allergies can be managed. It helps if you to adopt a cautious, not fearful, approach and develop a plan. Allergy management is a journey, but one most navigate quite successfully.

Experts in the allergy field advocate for a triple AAA rating when it comes to allergy management: Awareness, Avoidance, and Action (in the case of emergency). This three-pronged approach should give you some assurance and a good foundation to manage your sesame allergy. Your child’s allergies may even include other seeds such as sunflower, mustard, flax, or even perilla or hempseed.

Awareness: Educating Others

Sesame and seed allergies are on the rise, but many still find them unusual. It’s important that your family, friends, child’s coaches and teachers all know about the sesame or other seed allergy. Most people who care about your child will want to help out, although they might forget from time-to-time and offer foods that he or she can’t eat. That’s to be expected.

The concept of “tell, show, do” is a good one for building awareness. You can tell people about the allergy, and even print out a brochure about sesame that’s available from Health Canada. You can show them the auto-injector (and how it’s used) and the MedicAlert bracelet, or print off information about sesame allergy.

Make sure you fill out all the necessary anaphylaxis emergency plan form with photo for your child. Provide an auto-injector, and meet with teachers to discuss allergies and your strategy.

Make it your goal to build support and create a safe circle around you. Be helpful: Do volunteer to bring sesame and seed alternative foods to group parties: such as the buns without sesame or bring eggplant dip instead of hummus dip which often uses ground sesame. This helps you continue to fit in, and assists those who may be nervous about feeding your child.

Avoidance: Get Alternatives

Not eating or otherwise ingesting sesame (or other seeds) is the key to staying safe and healthy. Making your own food in a sesame-free home is the first line of defense. Many foods can be made with seedless alternatives: you bake granola bars without seeds, make hummus with chickpeas, garlic and olive oil.

Learn to read labels. Every time. The labeling of sesame and other seeds is not required in the U.S., but you can still call a manufacturer if you suspect it might be in the ingredients. In Canada, sesame is one of the priority allergens and must be listed in store-bought food ingredients. Learn the alternate names for sesame (see below) and beware of generic items like “spices” or “vegetable oil” that can contain sesame seeds or their oils.

Try to stick to foods from countries with stricter labeling requirements. Since sesame is used extensively in baking and imported foods from Asia – where there are not strict allergen controls, you may want to avoid buying those items and make an alternative versions of them at home.

Read food allergy labels carefully every time. Ingredients do change. One popular spaghetti sauce recently began adding sesame oil after years of using another type.

Next: Eating Out Safely

A recent Canadian population survey estimates that .23 per cent of Canadian children have a “probable” allergy to sesame, considerably less than the 1.68 per cent who have a probable allergy to peanuts and the 1.59 per cent to tree nuts.

Yet scientists say sesame allergy is on the rise, and at a far faster rate than other allergens. Sesame seed allergy is most commonly seen in children, but often carries on into adulthood as well, or can develop in adulthood.

People can also be allergic to many other seeds, including sunflower seed, mustard seed, rapeseed, flaxseed and poppy seed, although these allergies are much less common.

Mustard Seed Allergy

Canada is in the process of adding mustard seed to its list of priority allergens because, even though few people have the allergy, those who do tend to have severe reactions.

Mustard is already included on the European Union’s priority allergen list, but neither sesame nor mustard is currently included among the top allergens in the United States.

Allergies to seeds can be severe, and can cause anaphylaxis, the life-threatening allergic reaction that can affect multiple systems in the body, including the cardiovascular system, the respiratory tract, the skin and the gastrointestinal tract.

Symptoms can include tingling in the mouth, swelling around the face and throat, itchiness, difficulty breathing, abdominal cramping, vomiting and diarrhea, and even a sudden drop in blood pressure, loss of consciousness, or cardiac arrest, which can be fatal. As a result, it is critical that people with serious sesame, mustard or other seed allergies carry an auto-injector (an EpiPen or Twinject) with them at all times.

Why More?

There are several theories about why seed allergies, and especially sesame allergies, appear to be on the rise in North America. Scientists believe that the increased prevalence of sesame in our diets is at least partly to blame, with foods such as bagels, hummus, halva and other traditionally Middle Eastern and Asian foods, which used to be specialty items, having become mainstream favourites. (In countries such as Israel, where sesame has been a very common food for decades, sesame allergy is very common – even more so than tree nut or peanut.)

Sesame is also commonly added to rice cakes, granola bars, veggie burgers, sauces, soups, salad dressings, margarine and many other foods. Bakeries, as well as Middle Eastern and Asian restaurants are considered especially high-risk for people with sesame allergies.

Sesame seeds are also used in many cosmetics, soaps, hair-care products, and in some medications, sunscreens, ointments and pet foods, so it is relatively difficult to avoid.

See: Where Seeds Hide

Cross-Reactivity

People who are allergic to sesame also may react to poppy seeds, kiwi fruit, hazelnuts and rye grain, as the proteins in these foods are thought to be similar. A recent study has also shown a possible link between peanut allergy and sesame allergy, so the growing prevalence in peanut allergy may actually be playing a role in sesame’s increasing allergy presence.

However, while many peanut-allergic people may test positive for sesame on a skin test, they may still be able to eat it the seeds safely, so it’s important that they discuss the issue with their allergist.

Moreover, people who are allergic to one type of seed may not be allergic to others, or to the cross-reacting foods, so patients should work closely with their physicians to arrive at an accurate diagnosis.

Who Knew?

While allergies such as peanuts, tree nuts, wheat and milk are relatively familiar to the general public, fewer people have heard of sesame allergy. This is a concern for allergy practitioners and those living with sesame allergies since others may be less understanding or vigilant around a sesame allergy as opposed to a peanut allergy.

In one study of allergic parents in Boston, only one in five had understood the allergenic potential of sesame before their children tested positive.

Sesame at the Store

Since sesame is included on the priority allergens list in Canada and Europe,, this means those producing products containing sesame face stricter regulations when it comes to product labeling. As yet, sesame is not considered a priority allergen in the United States.

So in the U.S., it is not mandatory for food manufacturers to declare sesame on labels, and the seed may be hidden in ingredients such as “spices”, “natural flavor” and “tahini”. As a result, people with sesame allergies are encouraged to read product labels very carefully, and to contact food manufacturers when any ingredients are non-specific or unclear.

If you have an allergy to sesame, do not eat any food that may contain sesame, even in trace amounts.

Beware Sesame Oil

People who are allergic to sesame should also carefully avoid sesame oil. Unlike other oils such as corn and peanut oils, which are 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.

Perhaps you have experienced unexplained skin rashes (known as hives) or vomiting or diarrhea? Does your child refuse to eat a certain food, or complain that it makes his “tongue hurt”? These could be signs of a food allergy, and should be taken seriously.

It is common for the symptoms of food allergy to vary by individual – and from reaction to reaction in the same person. Not everyone will get all the symptoms, which range greatly in severity from mild to severe (and even fatal): your throat may feel tight on one exposure to your allergen or you may get itchy hives on your skin and vomiting with the next.

The Range of Symptoms

-Tingling in the mouth
-Swelling of the tongue and throat / feeling of throat tightness
-Itchy skin, hives or skin redness
-Abdominal cramps
-Vomiting or diarrhea
-Breathing difficulty, wheezing
-Faintness due to a sudden drop in blood pressure

Symptoms reviewed by Dr. Susan Waserman

Anaphylaxis

Anaphylaxis is the severe form of allergic reaction. It involves one or more of the body’s symptoms; for example, the gastrointestinal tract, the respiratory tract, the skin and the cardiovascular system. A person experiencing anaphylaxis often has difficulty breathing, and the person could lose consciousness. Anaphylaxis puts a person at risk of death.

Anaphylactic reactions can come on quickly, and it’s impossible to know when a reaction will become severe. It’s important that people with food allergies are prepared for a reaction by always carrying an epinephrine auto-injector (either EpiPen or Auvi-Q/Allerject).

Experts recommend using epinephrine early if a person known to be at risk of anaphylaxis begins to show signs of allergy symptoms – don’t wait until the symptoms worsen, as it may become to difficult put a halt to the reaction once it’s in progress.

But the patients coming through Ham Pong’s offices in Ottawa and Vancouver were telling a very different story. Not only were more of them reacting to sesame, but those reactions tended to be severe; in fact, more of his patients were experiencing full-blown anaphylaxis from eating sesame products than from shellfish.

A more formal survey of more than 2,000 patients confirmed the allergist’s suspicions – but many of his colleagues were still not convinced. “I presented a study at an allergy meeting, and one of the allergists didn’t believe that sesame was a problem. So he asked parents for a show of hands of how many of their children had sesame allergy, and he was very surprised “at how many hands went up,” recounts Ham Pong. “It took him aback because there was no published literature on its prevalence at the time.”

Since then, there has been a significant amount of scientific literature to show that sesame is yet another one of those especially problematic foods, to the point where the European Union and Canada have added it to their priority allergen lists, which include peanuts, tree nuts, dairy, wheat, eggs, fish, shellfish and soy. The United States is investigating whether to follow suit.

But sesame isn’t the only new culprit to gain priority status in Canada; nor is it the only emerging allergen on the radar of North American scientists. The fact is, our diets are constantly in flux – often because particular foods are found to have special disease-fighting properties and become trendy, or because people from around the world bring their culinary influences with them when they arrive on North American shores.

In turn, those foods – from sushi to hummus to curry – get woven into our ever more colorful mainstream diet. Those constantly changing grocery lists, however, mean that our society’s allergies are bound to see shift as well.

“Until kiwi became popular because of the high levels of vitamin C, you didn’t see a lot of kiwi allergy – but now you see a fair amount because it’s a very allergenic fruit,” says Ham Pong. “But if there wasn’t much of it in the diet, it wouldn’t really be an issue. So what makes a food a problem in society is how allergenic the food is, and how much that food is adopted as part of the daily diet.”

Open Sesame

That’s likely what happened with sesame, says Dr. Robert Wood, director of pediatric allergy and immunology at the Johns Hopkins University School of Medicine in Baltimore. The seed became more common in breads, the popularity of traditional Middle Eastern foods such as hummus skyrocketed, and bagels, which are often coated with sesame seeds, became a mainstay in the mainstream North American diet.

And unlike some oils such as peanut and corn whose proteins are almost entirely removed during the refining process, Wood adds that sesame is a raw oil, and as a result can be just as allergenic as the seeds themselves.

“In our practice, it has become much more common, and appears to be the fourth or fifth most common allergen we deal with,” says Wood. In addition to pointing the finger at the increased prevalence of sesame in our diets, Wood says that one of the most notorious allergens on the list may also be adding to the problem.

“We see sesame allergy more commonly in children who also have a peanut allergy, and we suspect that there are some similarities in the allergens in sesame and peanuts,” he explains. “So there may be some of the sesame allergy that’s actually being driven by the increase in peanut allergy.”

But because the prevalence of sesame allergy is relatively new, regulatory bodies have yet to catch up. In the United States, food manufacturers must clearly declare the top allergens on its product labels – but as yet, sesame has not yet made that list, so it can still be hidden as “tahini”, “spices” or “natural flavouring”. (It’s also used in cosmetics and pharmaceuticals.)

In Canada, sesame was added to the priority allergens list in 2000, and mustard is in the process of being added as well, but the country has yet to enact new regulations that require manufacturers to label all priority allergens in clear language.