Food Allergens

An allergy is used to describe a response, within the body, to a substance, which is not necessarily harmful in itself, but results in an immune response and a reaction that causes symptoms and disease in a predisposed person. All food allergies are caused by an immune system malfunction. The immune system identifies certain proteins as harmful, triggering the production of immunoglobulin E (IgE) antibodies to neutralize the proteins known as allergens. Allergens are organic compound that contain hydrogen, oxygen and nitrogen, which form an important part of living organisms. Allergens contain protein, which is often regarded as a constituent of the food that we eat. For these to cause an allergic response they need to be bound to a protein once they are in the body. An allergic person’s immune system believes allergens to be damaging and so produces a special type of antibody (IgE) to attack the invading material. This leads to other blood cells to release further chemicals (including histamine), which together cause the symptoms of an allergic reaction. The most common symptoms are: sneezing, runny nose, itchy eyes and ears, severe wheezing, coughing, shortness of breath, sinus problems, a sore palate, swelling, sickness, vomiting, diarrhea and nettle-like rash.Almost anything can be an allergen for someone, but the most common are: wheat, soy, milk, eggs, nuts, tree nuts, fish, shellfish and other, like sulfites, which are food intolerances and can be misdiagnosed as an allergen. There are some non-protein allergies that include drugs such as penicillin.

Wheat allergy is one of the eight most common food allergies. Wheat allergies often affect children, and can also occur in adults. Allergic reactions usually occur in susceptible individuals a few minutes to a few hours after they have consumed wheat. Signs and symptoms of wheat allergy range from mild to severe and can include skin reactions, congestion and digestive issues. Rarely, wheat allergy can cause anaphylaxis, a life-threatening reaction. Not all reactions to wheat are caused by wheat allergy. Some people have a digestive reaction to a sticky protein called gluten that is found in wheat and other grains. This reaction to gluten differs from a wheat allergy and can be caused by an inability to digest gluten (gluten intolerance) or by an allergic reaction to gluten known as celiac disease or gluten sensitive enteropathy. A wheat allergy occurs when the immune system mistakenly interprets the proteins in a product containing wheat as a harmful substance. When a person comes in contact with touching, breathing or eating with wheat the body produces antibodies to fight the harmful substance, and triggers an allergic reaction. There are four different proteins in wheat that can cause a range of allergies, albumin, globulin, gliadin and gluten.

Signs and symptoms of wheat allergy include: swelling, itching or irritation of the mouth or throat, hives or skin irritation, nasal congestion, airway inflammation and gastrointestinal symptoms such as cramps, nausea and vomiting. Allergy symptoms differ in various persons and generally occur a few minutes to a few hours after ingesting wheat. In some people allergic reactions occur when exercising after eating wheat and from inhaling flour in the work place (sometimes called baker’s asthma). Some people have severe reaction call anaphylaxis. This is a medical emergency and requires treatment with an epinephrine shot and a trip to the emergency room. Signs and symptoms start within seconds to two hours after eating wheat and can include constriction of the airways, including swollen throat or a lump in your throat that makes it difficult to breathe, shock, with severe drop in blood pressure, rapid pulse, dizziness, light headedness or loss of consciousness.

There are certain factors that may put one at a greater risk of developing wheat allergy and these include family history with hay fever, asthma, hives or eczema, age also, wheat allergy is most common in children, as they grow older. To evaluate a possible wheat allergy, a doctor may ask detailed questions about signs and symptoms, perform a physical exam, have one eliminate wheat from their diet and then have one eat the same foods to see if will cause a reaction. Skin and blood test maybe performed. The blood test measures the immune system response to wheat by measuring the amount of certain antibodies in your blood stream, known as immunoglobulin E (IgE) antibodies. The only way to prevent an allergic reaction is to avoid wheat and wheat protein altogether, this maybe difficult as wheat is a common food ingredient and read labels carefully.

Fish allergies are similar to shellfish allergies, in that they are more likely than many food allergies to start during adult and less likely than other allergies to be outgrown. Adults are more affected than children. Polack, salmon, cod, tuna, snapper, eel and tilapia are among the fish that commonly trigger fish allergies. There is a high allergic cross-reactivity among different types of fish meaning that people who are allergic to one type of fish, such as cod, often react to other types of fish such as hake, haddock mackerel and whiting, because allergens in fish are similar. Allergy that may masquerade as a fish allergy is an allergy to a fish parasite called Anisakis simplex. This parasite is considered a major allergen, and like fish allergies, can cause severe allergic reactions including anaphylactic shock. A fish allergy is developed when the body’s immune system is triggered when it mistakenly senses that a fish protein is an enemy substance and must be attacked and eliminated from the body. It releases histamines as a means of protection. Symptoms include: swelling, sneezing, hives, tingling in the mouth, gastro-intestinal problems such as diarrhea and vomiting, and a swollen throat and nasal passages can result in trouble breathing or in respiratory arrest known as anaphylactic shock. Severe reaction of anaphylactic shock must be treated in the emergency room. Diagnosis can be made by a skin test and a blood test.

As one of the major eight common food allergens, fish is covered under the Food Allergy Labeling and Consumer Protection Act (FALCPA). This requires that manufactures label the presence of fish is clear on food labels. Fish is an easier allergen to avoid than many of the other allergen because it is less pervasive in Western diets. Cooking does not destroy fish allergens. When eating out, seafood restaurants and sushi bars should be avoided because of potential cross contamination of other foods with fish.

Treatment of for fish allergy is not to eat any fish or products containing fish, careful to read labels. Foods that contain fish oils additives or proteins include Caesar salad dressing, Worcestershire sauce, gelatin, Thai fish sauce, fish stock and omega-3 supplements.

Soy allergy affects approximately 1% of people in the US mainly infants. Soy, also called soya is one of the top eight most common foods that triggers allergies in children. Soy allergy often begins with the introduction of soy-based formula for infants which is mainly due to a switch from cow’s milk-based formula. This reaction may occur after 1 to 2 weeks of starting the formula. Although, most children outgrow this allergy by age 3, some persist and it is becoming more common in adults.

The signs and symptoms of soy allergy are mild, but can be serious in rare cases by a life-threatening reaction called anaphylaxis. Death due to soy allergy has occurred in people who have both a severe peanut allergy and asthma. The symptoms of soy allergy are tingling of the mouth, hives, itching or eczema, swelling of the lips, face, tongue and throat and other parts of the body, canker sore, wheezing runny nose or trouble breathing, abdominal pain, diarrhea, nausea or vomiting, dizziness, lightheadedness or fainting. In a severe case, more extreme signs and symptoms occur such as constriction of airways, difficulty breathing, severe drop in blood pressure, rapid pulse, dizziness, lightheadedness or loss of consciousness.

All food allergies including soy are caused by an abnormal response of the body’s defense mechanism called immune system. People with food allergies have an antibody called immunoglobulin E or IgE. Soybean allergy involves the production of protein (allergen) specific IgE antibodies in certain individuals upon exposure to soy protein, following the production these antibodies travel to cells called mast cells, which are found mainly in parts of the body like the nose, eyes, lungs, and gastrointestinal tract. The IgE then attaches to the surface of the mast cells and waits for their particular allergen. On contact at another time the allergens are captured by the IgE antibody, which initiates the release of histamine and other body chemicals from the mast cells which produces the symptoms of the allergic reaction.

There are 2 major cross-reactivity concerns with soy; first between soy and birch pollen and second with other legumes, especially peanuts, however most people with this form of allergy can tolerate peanuts, peas and other legumes.

Test and diagnosis is similar to those of other allergies – blood and skin tests. The only sure treatment is to avoid soybeans and all soy products and use medications such as antihistamines. If there is a serious allergic reaction, an emergency room visit is needed for an emergency injection of epinephrine (adrenaline).

Milk allergy is another one of the most common allergy causing foods in children and is the leading cause of allergic reaction reactions in infants and young children. It affects about 1-7.5% infants in the US due to the proteins found in cow’s milk and cow’s milk-based formulas. It is outgrown in children by age 2 or 3. Infants are thought to be susceptible to this allergic syndrome because of their immature immune and digestive systems.

The allergic reaction usually occurs a few minutes to a few hours after consumption, but in some cases it can take days before signs and symptoms occur also within the days to months of birth.

The signs and symptoms range from mild to severe, differs from person to person, occurs within minutes to a few hours of ingesting milk and also after exposure to milk for an extended period of time. Infants rarely have an allergic reaction to smalls amounts of cow’s milk protein passed along through the mother’s breast milk.

Immediately occurring symptoms of milk allergy are: wheezing; vomiting; hives; but loose stool that contains blood and mucus; diarrhea; abdominal cramps; coughing; skin rashes and runny nose may take sometime to develop. Milk allergy rarely causes anaphylaxis, which shows immediate symptoms and signs after consuming milk.

There are two types of proteins in milk that causes an allergic reaction: Casein – found only in the solid portion (curd) of milk which curdles; and Whey – found in the liquid portion that remains after milk curdles. A person can be allergic to either one of these proteins or both, but they are not only present in milk but other processed foods.

This allergy is caused by the immune system identifying either of these two proteins as harmful to the body, which causes the production of IgE antibody that neutralizes the protein called an allergen. When the body comes in contact with the allergen again, the IgE antibodies recognize it and signal the immune system to produce histamine and other chemicals which causes the range to allergic signs and symptoms.

Children allergic to milk are more likely to develop certain health problems such as an allergy to pet dander, dust mites, grass pollen and other substances and also gastroesophageal reflux disease (GERD), a type of heartburn which causes stomach acid or bile refluxes into the esophagus.

Some people with milk allergies can consume certain milk products that have been processed and this is based on the type of protein causing the reaction because persons whose allergy is caused by casein most likely react to all milk products, but those allergic to whey may be able to tolerate certain milk products such as cheese and milk treated at high heat.

Evaluation for a possible milk allergy is done as follows: detailed questions are asked by a doctor about the signs and symptoms, physical examination is performed, a detailed diary of the foods eaten is kept and the elimination of milk from the diet. A skin and blood test may also be recommended.

Prevention of this allergy is to avoid all milk products, and know what is consumed by your child. For infants, breast-feeding is the best source of nutrition for the child and it highly recommended by doctors to reduce the chance of developing milk allergy. Also, the uses of hypoallergenic, soy-based and meat-based formulas are recommended. The egg is one of the most common allergy-causing foods. The egg allergy is more common in children, and most will outgrow it by five years old. The signs and symptoms range from mild to severe and can occur immediately or within a few hours. From mild to severe, the signs and symptoms of an egg allergy reaction are skin inflammation or hives (the most common reaction), allergic asthma, allergic nasal inflammation, gastrointestinal issues (cramps, nausea, vomiting), and anaphylaxis. The milder symptoms may be treated with over-the-counter antihistamines to relieve discomfort; however, anaphylaxis is a life-threatening condition that must be treated with a shot of epinephrine and immediate medical attention. The symptoms of anaphylaxis include constriction of airways, shock, rapid pulse, dizziness, lightheadedness, and/or loss of consciousness.

The egg allergy has many risk factors. First, most people who are allergic to eggs are usually have other allergies as well. Cow’s milk and peanuts are two other allergies commonly associated with the egg allergy. Second, the skin condition atopic dermatitis is typically seen in conjunction with this allergy. If a child has this type of eczema, there is a greater chance of their developing an egg allergy. Third, family history is a risk factor for this allergy. If one or both parents have a food allergy or another kind of allergy (hay fever, asthma, hives or eczema), there is an increased risk of the children developing the egg allergy. Last, age is a risk factor. As previously stated, this allergy is more common in children. As most of them get older, however, their digestive systems will mature and be able to tolerate the egg protein.

Children with egg allergies are more likely to develop other health problems and allergies. Some may develop an allergy to other foods such as milk, soy or peanuts. They also may develop hay fever, an allergy involving pet dander, dust mites or grass pollen. Atopic dermatitis and asthma are two additional complications linked to the egg allergy. Some adults and children who have the egg allergy will also develop an allergy to duck and quail eggs. In addition, people with these additional egg allergies may develop an allergy to chicken which is called Bird-egg syndrome. Diagnosis techniques include physical exam, keeping a detailed food diary for your doctor, and performing an elimination diet. In addition, your doctor may request a skin test or a blood test (IgE antibodies).

Prevention is key in steering clear of a reaction to an egg allergy. If you (or your child) have been diagnosed with an egg allergy, there are several ways to evade both mild and severe reactions. Avoiding all egg products and products that contain egg-based ingredients is the first step. This can be done by knowing what you (or your child) are eating and drinking. Understanding how egg products are labeled and being sure to read the labels carefully are vital steps in avoiding eggs and egg products. To prevent a skin reaction, do not touch eggs or egg-containing products. Lastly, if you (or your child) are at risk of having a severe reaction, you should carry injectible epinephrine (EpiPen) at all times. You may also choose to wear (or have your child wear) a medical alert bracelet or necklace to alert other people should a sever reaction occur. There is one suggested way to prevent developing the allergy altogether. If you wait until your child is two years old before giving them eggs, the likelihood of their developing an egg allergy decreases.

There are many foods that have hidden sources of eggs and egg products. In addition to reading the food label, be aware that the term “egg-free” does not mean that the food is completely free of the egg proteins that cause allergies. There are many terms to be aware of when inspecting a food label: albumin, albuminate, globulin, lecithin, livetin, lysozyme, vitellin, and any workds starting with “ovo” or “ova”. Some food products that contain hidden sources of eggs are mayonnaise, marshmallows, simplesse (a fat substitute), and meringue. Some foods that may contain eggs are salad dressings, baked goods, frostings, pudding, pastas, and processed meats. There are also some nonfood products that contain eggs and may cause reactions: shampoos, medications, cosmetics and some vaccines. The flu vaccine and yellow fever vaccine contain small amounts of egg proteins and can be safely given to many people with the egg allergy. Talking to your doctor is the most efficient way to determine whether the vaccine is likely to cause a reaction.

The allergy to shellfish is another one of the most common food allergies. This allergy is more common in adults, but can occur in children. Allergic reactions to shellfish occur shortly after exposure. Some of the signs and symptoms include hives, itching, eczema, swelling of the lips, face or throat, wheezing, nasal congestion, trouble breathing, abdominal pain, diarrhea, nausea, vomiting, dizziness, fainting, or tingling in the mouth. The most severe reaction is anaphylaxis.

There are many different types of shellfish. Each type of shellfish contains a different allergy-causing protein. Because of this, some people react to and must avoid all shellfish while other people are allergic to one kind and can eat others. The many different shellfish fall into two categories: crustaceans and mollusks. Crustaceans include shrimp, crabs, lobster, crayfish, and prawns. Mollusks include bivalves (clams, mussels, oysters, scallops, and abalone), gastropods (limpets, periwinkles, and snails), and cephalopods (squid, cuttlefish, and octopus). People who are allergic to shellfish won’t typically have a reaction to fish unless they also have a fish allergy.

The only two risk factors associated with the shellfish allergy are family history and age/gender. Similar to the egg allergy, if allergies of any type are prevalent in your family there is an increased risk of developing a shellfish allergy. People of any age and gender may develop a shellfish allergy; however, it is most common in boys and women. Diagnosis techniques include a skin test and a blood test (RAST – Radioallergosorbent test).

Reaction prevention is quite simple when dealing with a shellfish allergy. Similar to most allergies, avoidance is the most successful. Shellfish are rarely used as an ingredient, so they are easier to avoid than some allergy-causing foods. Eating in restaurants increases the likelihood of coming in contact with shellfish. If you have a shellfish allergy, you may be able to prevent contact with shellfish in restaurants by checking the pans yourself or asking the workers to prevent “cross-contamination”. The most successful way to prevent a reaction is by completely avoiding places where shellfish are processed and handled. Another vital step in preventing a reaction is to carefully read food labels. Additionally, avoiding coral calcium will prevent a reaction. Coral calcium comes from ocean coral reefs and may contain shellfish proteins. Glucosamine, the over-the-counter aid for preventing and treating arthritis, is made from crab, shrimp and lobster shells. Most people with an allergy to shellfish don’t react to this supplement; however, more studies are needed before it can be labeled safe.

According to the Center for Food Safety and Applied Nutrition, as of 2006, up to 6% of children and 4% of the total population have IgE-mediated food allergies. They also reported that severe food-related allergic reactions result in an estimated 30,000 emergency room visits, 2,000 hospitalizations, and 150 deaths per year. Between 1997 and 2002, data indicated an apparent doubling of peanut allergy in children under five years old. The most common causes for fatal reactions in the U.S. are reactions to peanuts and tree-nuts. The most common allergy in children is milk, while the most common allergy in adults is peanuts.

Peanuts are another cause of allergies. Typical symptoms of a peanut allergy occur within minutes after contact or consumption of peanuts, however the reaction can sometimes be delayed by up to an hour. While symptoms vary from person to person, many of the common reactions to peanut allergies are: stomach ache, itchy eyes, itchy skin rash, hives, runny nose, and tingling tongue or lips. Often times, those initial reactions begin to lessen as time passes, but they can also escalate into more severe symptoms including: tightening of the throat, hoarse voice, nausea and vomiting, diarrhea, and coughing or wheezing. One of the most severe allergic reactions to peanuts is called anaphylaxis which occurs when the bronchial tissue in the lungs expands, causing the airways to contract; the person then has much difficulty breathing, lips turn blue, swelling in the face, and the person feels dizzy. Anaphylaxis can be fatal in as little as ten minutes if immediate medical treatment is not rendered.

There are two ways to medically test for peanut allergies. One method is a skin test, where small needle pricks are used to expose the person to extremely minute amounts of peanut proteins. A positive result for this test would be if hives develop at the prick site. The second medical test for peanut allergies is a blood test. For this examination, blood is drawn from the patient and laboratory analysis measures the amount of immunoglobulin E antibodies, which are specific to peanut allergies, there are present in the blood.

There is currently no cure or approved therapies for peanut allergies. The main method of keeping these allergies under control is strict dietary management, and removal of all peanut derived products from the diet. Some people with extreme sensitivity to peanuts carry an auto-injectable epinephrine which is the same prescription medication administered at the emergency room to control anaphylaxis. People with peanut allergies sometimes carry over-the-counter antihistamines which are taken after exposure and allergic reaction to peanuts to prevent the full onset of the reaction and relieve some symptoms.

Tree nut allergy is one of the most common food allergies in both children and adults. Some examples of tree nuts include cashews, walnuts, and almonds. This allergy can cause severe reactions in allergic people even if the person is exposed to minute amounts of tree nuts. Tree nut allergies are usually life-long and people are advised to stay away from al tree nuts if they have this allergy because it is unlikely to be allergic to just one type of tree nut.

Tree nuts cause similar symptoms and reactions as do peanut allergies. Some reactions are: tingling feeling in lips and mouth, itchy hives, swelling in the skin, vomiting, diarrhea, stomach pains, dizziness, and difficulty breathing due to swelling in the throat. Allergic reactions to tree nuts have a wide range of severity. Some reactions are mild anaphylaxis which involve two or more bodily systems, while other people may experience life-threatening anaphylactic shock. Since there is no way of predicting how bad any one reaction can get, people experiencing even mild symptoms should seek medical treatment. People with severe reactions to tree nuts can die from constriction of the air passageways and dangerous drops in blood pressure.

Tree nut allergies can be detected through a simple skin test which involves pricking or injecting tree nut extract into an individual's skin. Another medical test for tree nut allergies is the RAST (radioallergosorbent test) which is a blood test that detects antibodies in a blood sample from the individual.

Just as with peanut allergies, there is no known cure for tree nut allergies. This means that the only way to avoid an allergic reaction is to eliminate any traces of tree nuts and tree nut extracts from the diet. This not only means avoiding tree nuts and foods with tree nuts in them, but it also means that the individual has to make sure that the food preparation has no traces of tree nuts; meaning the cooking utensils, machines, and manufacturing procedures must be completely free of any traces of tree nuts. Epinephrine is a synthetic form of adrenaline that is injected into the individual with a reaction and can reverse the symptoms of anaphylactic shock by opening breathing tubes and restoring normal respiration. Antihistamines are also used to lessen the severity of a reaction to tree nuts.

Although the United States has yet to consider adding Sesame seeds to its list of major allergens, Canada and the European Commission have already done so. Perhaps this is due to the fact that, the more popular a food is in a particular country, the better the chances are that it will be reported as a food allergen. For instance, though the American diet may not be rich in sesame seeds, it has been found that sesame is the third most common allergen in Israeli children lagging behind only cow’s milk and eggs as a result of its predominance in the Israeli diet. Allergies to other seeds do exist, but they are significantly less common. It is important to note that, an allergy to one specific seed does not indicate an allergy to all types of seeds. Therefore, the matter should be discussed with a doctor. To date, FALCPA does not require that food labels mention sesame or any other type of seeds on their ingredient labels. Careful observation of food labeling is required for those who are allergic. It is important to beware of vague ingredient lists i.e. “spices”, for these may very well contain seeds. It is advisable that allergic consumers call the manufacturer to inquire about the specifics of the ingredient list, and check labels frequently, for product ingredients can change over time. Ingredients and foods such as Benne, Gomasio (sesame salt), Halvah, Hummus, Tahini, Seeds, Sesame oil (gingelly or til oil), Sesamol/sesamolina, Sesamum indicum, Sim sim and Vegetable oil all indicate the presence of sesame. Additionally, many baked goods, snack foods, dressings, sauces, dips, margarines, soups, processed meats, and vegetarian burgers are known for containing sesame and other seeds.

In 2004, the Food Allergen Labeling and Consumer Protection Act (FALCPA) was added to section 403 of the Federal Food, Drug, and Cosmetic Act. The amendment declared that food manufacturers must include common allergens in the ingredients list, or next to it, and that the name by which the allergen is typically recognized must be included in parenthesis after the name of the food source from which it was derived. It was not until January 2006 that revised labels appeared on shelves under the 2004 FALCPA provisions. The FDA implemented these guidelines in order to take some of the guess work out of food consumption for those inflicted with food allergies. For instance, while most assume that non dairy products do not contain milk, oftentimes milk byproducts may be present. After the label guidelines were adjusted, the term milk had to be listed in parenthesis after the byproduct name. These rules apply to any domestic or imported packaged food. Fresh fruit, meat, and some highly refined oils are exempt from labeling, as are products that may come into contact with allergens during the growing, harvesting, or manufacturing of the product.

However, the FDA has recently expressed concern that food labeling under the 2004 act may be unclear, inconsistent, and altogether insufficient in keeping those affected by food allergies safe. The 2004 law requires manufacturers to give advisory warnings if any of the eight major food allergens are ingredients in a food product. However, products that may come into contact with the allergens during production do not require advisory warnings. This is dangerous because, oftentimes in manufacturing facilities, production equipment may cause cross-contamination, where trace amounts of allergens are transferred into non-allergen containing food products.

Anne Munoz-Furlong, the founder and CEO of FAAN (Food Allergy & Anaphylaxis Network) claims that there are more than thirty different variations of advisory warning labels being used by companies today, which makes it hard to distinguish companies that truly want to warn their customers from those that simply want to avoid liabilities. She also thinks that vague “may contain” statements found on food packages leave consumers with an ultimatum; to either maintain a severely strict diet or take a huge risk in consuming poorly labeled products. Teenagers in particular are reporting that they are taking risks as a result of the imprecise labeling. Meanwhile, about 30,000 emergency room visits per year in the U.S. are attributed to food allergies.

Suggestions have been made that the FDA determine allergen thresholds, or levels at which the presence of an allergen may be considered safe and exempt from strict advisory warning since complete separation of products and thorough cleaning of machinery are unfeasible for many manufacturers. However, some believe that a label change will not be quite enough to eliminate the grey area that the FDA is hoping to remove. This is due to the fact that everyone reacts differently to the presence of food allergens. Some people with food allergies may not be highly susceptible to trace amounts, while others are extremely sensitive. These issues cannot be solved with the change of a label.

The eight major food allergens are: wheat, fish, peanuts, tree nuts, soy, milk, egg, and shellfish allergens. The signs and symptoms of all of these allergens are basically the same and consist of trouble breathing, hives and skin rashes, and most severe cases result in anaphylaxis. One additional allergen that did not make the top eight is a sesame and other types of seeds. As for food labeling, the FDA requires that manufacturers must include the common allergens in the ingredients list as part of the Food Allergen Labeling and Consumer Protection Act, however traces of allergens that may end up in the product as a result of processing is not required on the label. Since currently there no available cure for any food allergens, the best way to prevent allergic reactions is to completely eliminate the allergen from the diet.