If you have food allergies or intolerances, you will need to go through the ingredient lists and change your meal plan. However, the real problem is often finding out what you cannot accept. We will tell you how.
Scientists at Harvard recently analyzed 2.7 million files of American patients. Result: About four percent of people suffer from food allergies. Similar figures for Switzerland. According to the Federal Food and Veterinary Administration, two to eight percent of adults have food allergies.
Food intolerances, such as lactose intolerance, are much more common – up to 20 percent of people.
Affected people should read the ingredient lists carefully to avoid unpleasant surprises after dinner, which can range from grunting in the stomach to severe flatulence, skin rashes, dizziness, and anaphylactic shock. And it’s not always easy to associate certain foods with symptoms. Result: people don’t know what is missing.
In this article, you will learn what happens to food allergies in the body, what symptoms indicate an allergy, and how to find out with blood tests and inactive diets. See also: types, symptoms and treatment of food intolerances.
What is food allergy?
When you are allergic, your immune system reacts to a harmless substance. These substances that can cause allergies are called allergens. These are various proteins found, for example, in pollen, animal hair, house dust mite excrement and food.
What happens to allergies in the body?
Allergy always begins with sensitization to the allergen. This means that the body is producing too many specific IgE antibodies. These immunoglobulins (which is what Ig stands for) specialize in keeping some intruders out of the body. For example, the immune system fights bacteria, viruses, worms and, unfortunately, harmless allergens.
IgE antibodies bind to receptors on mast cells, cells of the immune system. Laboratories can detect an increased amount of IgE antibodies in the blood and prescribe antibodies to the corresponding allergens – this is how an allergy test works with a blood sample. If the allergen comes in contact again, it binds to the IgE antibodies and causes the mast cells to release substances such as histamine. Histamine promotes inflammation and thus causes various allergy symptoms. If this leads not only to sensitization, but also to complaints, we are talking about an allergy.
Types of food allergies
Experts distinguish between different types of allergies. The most common form of allergy is type I immediate allergy, which also includes food allergies. The reaction occurs immediately after consuming the allergen. The peanut allergy then experiences symptoms such as a furry tongue and a rash a few seconds or 20 minutes after eating. Delayed immediate reactions are also possible, in which another allergic reaction occurs four to six hours later.
Good to know: Some food allergies go away on their own in adulthood. Allergies to milk, eggs, soy and wheat mainly affect children and disappear in 90 percent of cases. However, allergies to nuts, fish and shellfish usually persist throughout their lives.
How does food allergy develop?
Allergies are called “common diseases” today. In recent decades, the number of allergic diseases has increased more and more. Scientists are still not entirely sure why. A popular explanation is the hygiene hypothesis, which blames a lifestyle other than dirt and germs for the spread of allergies. But genetic factors obviously play a role as well.
Is the allergy inherited?
As a rule, no one is born with allergies. But people can have a genetic predisposition to allergies. You have a significantly higher risk of developing allergies. This often applies to allergies in general, that is, children of hay fever parents are sensitive to all allergies, whether they are pollen, animal hair, or food. This also applies to other so-called topical diseases, which are closely associated with allergies and often occur with them, especially in neurodermatitis and asthma.
Good to know: In infancy, the uterus is our home and influences the development of our body. Therefore, the mother’s diet can also influence the development of allergies. In addition, C-section and older mothers increase the risk of food allergies.
Does dirt protect against allergies?
The hygiene hypothesis is based on one observation: allergies are especially common in cities and much less common in children who grew up on a farm.
According to the theory, in the hygienic conditions in which we work in the Western world, our immune system rarely encounters foreign bodies such as pathogens, worms and parasites. The immune system has nothing to do and uses its power to protect itself from harmless substances such as food and pollen – allergies occur.
Good to know: Do we develop allergies during life? It is resolved in the first months of life, perhaps even in the womb. So it depends on the environment babies are in early in their lives – later farm holidays will not prevent allergies.
What role does the gut play in the development of allergies?
intestinal flora (also microbiome) describes the composition of the billions of bacteria that live in our gut. From an early age, this microbiome plays a key role in the development of our immune system. Researchers suspect that our modern lifestyle affects gut bacteria, which in turn influences the development of allergies.
A study from Estonia showed that Estonian children, who are relatively often raised on farms and spend a lot of time outdoors, have significantly better intestinal bacterial colonization than children from Sweden, who are less likely to grow up on farms.
Does breast milk protect against allergies?
For the healthy development of the immune system, it is ideal if mothers breastfeed their baby for at least four months. A few years ago, strict dietary guidelines were recommended. To reduce the risk of allergies in a baby, breastfeeding women should avoid eggs, sometimes nuts, dairy or wheat products. Experts have also advised not to mix baby cereal with gluten-containing cereals. Fish was as taboo as celery or carrots.
New research has turned these recommendations 180 degrees. They showed that babies are more likely to tolerate food if they come into contact with the uterus or breastfeed. Of course, this only applies if the child has not yet developed an allergy!
Good to know: If your baby is allergic to food, you, as a mother, should avoid eating appropriate foods while breastfeeding.
How can you prevent allergies?
The development of allergies is a complex process that scientists still have not fully understood. Accordingly, there are no hard and fast tips that can be used to prevent allergies.
However, medical advice contains recommendations that can reduce the likelihood of allergies. They target families at risk, that is, families that already have allergies, neurodermatitis or asthma. Recommendations include:
- Mother and baby should not avoid allergens in their diets, mother’s consumption of fish may also have protective effects.
- After pregnancy, mothers should avoid tobacco smoke.
- Pregnant women, nursing mothers and children should not come into contact with mold.
- Pets are not a problem, they can even reduce the risk of allergies – if the child is no longer at high risk of developing allergies. In this case, you must not keep a cat.
- You must minimize the exhaust fumes from your vehicles.
Foods that cause allergies
170 foods are considered allergens, but most reactions are caused by multiple foods. The most common allergy triggers are cow’s milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish.
Cow’s milk allergy
milk allergy is the most common food allergy. It usually develops during childhood and usually goes away again at school age. People who are allergic to cow’s milk react to all dairy products, including cheese, yogurt, butter and cream, and 92 percent are also allergic to goat’s milk. People with a cow’s milk reaction should also avoid products made from goat’s and sheep’s milk.
Important: cow’s milk allergy is a completely different disease from lactose intolerance chicken egg allergy
Chicken Egg Allergy
Chicken egg allergy is the second most common childhood food allergy after cow’s milk allergy. He also often grows into adulthood.
Good to know: Some foods are less likely to cause allergies when cooked. For example, many allergy sufferers tolerate very hot milk or eggs used for baking much better. In turn, peanuts have a higher allergic potential when roasted.
Allergy to nuts
For nut allergies, healthcare professionals distinguish between peanut allergies – actually legumes – and other nuts, which they call tree nuts. All nut allergies tend to cause violent reactions up to anaphylactic shock, relatively often.
Allergy to fish and shellfish
Fish allergy often occurs only in adulthood. Affected people usually cannot tolerate all types of fish. Most people with fish allergies can easily eat shellfish and vice versa.
Shellfish allergy also usually develops in adulthood. Shellfish include all crustaceans including crabs and lobsters, shellfish (snails) including oysters, scallops and squid, and insects such as cockroaches and grasshoppers. Because house dust mites are shellfish, people who are allergic to shellfish are often allergic to house dust.
Wheat allergy most often develops during childhood and usually resolves before maturity. 20 percent of wheat allergy sufferers cross-react to other grains such as spelled and rye. However, you shouldn’t give up your suspicions about whole grains – it limits your diet too much. If in doubt, do an allergy test. It is best to do a provocative test to find out what you are really putting up with.
Important: Wheat allergy is not celiac disease! As a wheat allergy, foods containing gluten can be consumed as long as they do not contain wheat.
Spices are found in all types of processed foods, cosmetics, and dentifrices. However, they should not be marked on the packaging. This makes it difficult for allergy sufferers to avoid certain spices. However, spice allergies are relatively rare. The most common are cinnamon and garlic allergies, less often black pepper and vanilla reactions occur.
Not all food causes an allergic reaction, but allergens in certain protein substances. Sometimes some of these proteins are so similar that the body cannot distinguish between them. In this case, a cross-reaction can take place: the body is sensitized to one allergen, but also reacts to another. This happens between foods – those who are allergic to peaches often react to apples as well. But it can also happen that pollen allergy results in cross-reactions with fruits, vegetables and nuts. And even latex often causes cross-allergies compared to kiwi, bananas and avodakos.
Food and possible cross-allergies:
|Allergy to||Cross-Reactions to||Risk of Cross-Allergy|
|Cow’s milk||Goat’s milk||92 percent|
|Cantaloupe melon||Watermelon, banana, avocado||92 percent|
|Shrimp||Crab, Lobster||75 percent|
|Peaches||Apples, plums, cherries, pears||55 percent|
|Pollen||Apples, peaches, melon||55 percent|
|Salmon||Swordfish sole||50 percent|
|Walnuts||Brazil nuts, cashews, hazelnuts||37 percent|
|Latex||Kiwi, banana, avocado||35 percent|
|Wheat||Barley, rye||20 percent|
Food Allergy Symptoms
There are many symptoms that can indicate an allergy or intolerance. Some are light and barely visible, others are difficult to miss, and others are very difficult, such as allergic shock. Food allergies have long affected not only the mouth and gastrointestinal tract, but also the skin and respiratory tract.
What are the symptoms of a food allergy?
The following symptoms often occur with allergic reactions:
- Skin redness and flaking (nettle fever)
- Diarrhea, vomiting and abdominal pain
- A burning sensation in the mouth, swelling of the mucous membranes and tongue
- Shortness of breath in allergic asthma
- Drop in blood pressure
Extreme case: allergic shock
The most severe allergic reaction is allergic shock, also called anaphylactic shock. The reason is mainly insecticides, medications and, especially in children, food. Among the food items, nuts, soy, shellfish, milk and eggs are shocking.
In case of allergic shock, a large amount of histamine is released, which leads to a strong expansion of the blood vessels. This causes a rapid drop in blood pressure, causing dizziness, fainting and, in the worst case, even death.
If the risk of shock is known, you should react quickly if severe allergy symptoms develop and call an emergency doctor immediately. Before the arrival of the ambulance doctor, the victim should be in shock, that is, lie down and raise his legs. Patients at risk often also carry an emergency kit that contains an adrenaline pen. This emergency medicine can relieve shock.
Good to know: depending on the severity of the allergy, even the smallest amount of allergen is sometimes enough to cause an allergic shock – for example, traces of nuts on your partner’s lips or traces of soy on certain foods .
The fact that you are allergic does not automatically react to the slightest signs of allergy. There is a so-called reaction threshold, that is, a certain amount of allergen, due to which complaints arise. For example, peanut allergy sufferers often have a very low threshold for reaction, and a small peanut crumb is enough to cause a fluffy tongue and a swollen neck.
Stress, exercise, and infection can lower your threshold for response. This will increase the likelihood of an allergic reaction.
During or after sports, the risk of an allergic reaction increases. The phenomenon even has a name: exercise-induced anaphylaxis (EIA). Eating foods that you are allergic to just before exercise may cause hives and itching or dizziness. You should avoid food allergens at least four to five hours before each workout.
Research has shown that stress can worsen allergy symptoms and become more common. If you have allergies and are often stressed, you should try to relax purposefully. Relaxation techniques such as yoga, autogenic training, and progressive muscle relaxation can help.
Infections such as the flu or colds can also aggravate allergies. Higher temperatures lead to increased circulation, which in turn allows more of the allergen to enter the bloodstream. In the case of infections in the gastrointestinal tract, it is aggravated that more undigested proteins penetrate through the mucous membrane. As a result, these proteins interfere with the sensitive immune system and are more likely to cause an allergic reaction.
Alcohol is viewed by scientists as an aggravating factor in allergies. In some case studies, allergy symptoms worsened with alcohol exposure, and antibodies to IgE increased in alcoholics. However, there is no conclusive scientific evidence for this theory.
Food Allergy Test
Do you suspect that you cannot tolerate certain foods because symptoms such as a skin rash, furry tongue, or gastrointestinal symptoms always appear after eating? Then it might be worth checking for food allergies. There are four common health tests that can detect allergies:
- Injection test
- Blood test for IgE antibodies
- Elimination Diet
- Oral provocative test
An injection and a blood test give indications for sensitization to certain allergens. The elimination diet and challenge test are used to detect allergies with complaints of sensitization.
During a prick test, the doctor combes the allergens dissolved in the liquid under the skin, usually on the forearm or back. If flakes form at one point, it means that there is a sensitization to the allergen introduced at that point.
The injection test is quick and painless, but can cause severe itching afterwards.
Allergy IgE blood test
Laboratories may look for specific IgE antibodies in the blood. The advantage of this blood test is that you can use the blood test to check for a variety of food allergies. If the specific antibodies are particularly prevalent in your blood, you are sensitized to the associated allergen.
However, this does not mean that you are allergic! In addition, complaints should arise when eating the food in question. In some cases, this is not difficult to notice. In others, reactions are delayed or ambiguous. Then an elimination diet or challenge test may help.
Sometimes, according to an IgE blood test, you have an increased sensitivity to food, but you have no complaints when you eat it. In this case, you should not completely remove it from the menu. Your body probably has one immune tolerance has developed, but it can lose it if you don’t eat for a long time. It is recommended that you only eat every four days. This will ensure that your intestines are not overloaded. Another possibility is that cross-reaction with inhaled allergens is the actual cause of the measured response.
Cerascreen® Food Reaction Test
You don’t need to have an IgE blood test done by a doctor. A self-test, such as the cerascreen® Food Reaction Test, allows you to take a blood sample yourself with a small spatula in your finger. Then send the sample to a specialized laboratory that will test your blood for specific IgE antibodies. The products tested in the test cover 95 percent of the common causes of food allergies in Europe.
With an elimination diet, you remove foods you suspect are causing allergies from your menu. Such a diet is often the first measure doctors prescribe when a shot or blood test shows sensitization.
You shouldn’t stick to an exceptional diet for more than two to four weeks if you want to learn about food allergies and only one meal at a time. During this time, you can already see the first effects if you are allergic to food – changes are often felt very quickly.
Provocative tests can finally confirm food allergies. This test should always be done by a doctor as there is a risk of allergic shock. The doctor will give you the food you want to test and will find out if there are any reactions. If there are no symptoms, there is no allergy.
Food allergy therapy
Food allergies cannot be cured. If you have it, you must live with it until it disappears on its own. However, based on a reliable diagnosis, you can avoid triggers, treat worse symptoms with medication, and prepare yourself for anaphylactic shock with an emergency kit.
Avoid triggers and eat a balanced diet
Obviously, if you have food allergies, you should no longer consume this food – even in small quantities. If the allergy is accompanied by severe symptoms or even there is a risk of allergic shock, you should carefully examine the ingredients on the package. Heavily processed foods often contain ingredients you might not expect.
EU regulation requires food manufacturers to label the 14 most common allergy and intolerance triggers on their products in bold: gluten-containing cereals, crustaceans, eggs, fish, peanuts, soybeans Dairy products , nuts (nuts), celery, mustard, sesame seeds, sulfur dioxide and sulfites, lupine, shellfish. The term “May contain traces” is not regulated and is used voluntarily by manufacturers.
If you can’t carry one or two dishes, it’s easy to remove them from the menu and replace them. If you or your family has a lot of food allergies, it quickly becomes difficult. In this case, experts recommend nutritional advice. You will learn how to avoid allergens while maintaining a balanced diet.
Antihistamines, also known as anti-allergenic pills, weaken or cancel the effect of the histamine messenger. Thus, they can reduce allergic reactions throughout the body. They are used for hay fever, but may also reduce minor food allergy symptoms such as rashes, itchy palate, and nausea. The most common active ingredients are cetirizine and loratadine and are available as drops and tablets over the counter from pharmacies.
In case of allergic shock, the effect of antichstamines is usually insufficient. This is why people who are severely allergic to more dangerous allergens, such as nuts and shellfish, often have a spare kit with them. The emergency kit contains an adrenaline pen that is injected into the thigh, glucocorticoids and, for asthmatics, also an inhalation spray.
Food allergy, as defined, is always a reaction of the immune system, in which certain antibodies play a role, mainly IgE antibodies. This can be distinguished from food intolerances, which cause non-immunological reactions to food. The term intolerance is often used instead of intolerance.
Incompatibilities include celiac disease (gluten sensitivity), lactose, fructose, sorbitol and histamine intolerance, and IgG4 mediated intolerance. According to experts, from 15 to 20 percent of the world’s population suffer from intolerance, women more often than men. The causes of intolerance are not always clear; genetic predisposition and environmental influences are possible factors.
Many people think they have food intolerances, but in fact only a fraction of them. According to a survey conducted in the UK, 20 percent of people believed they had food intolerances in their household. However, studies have shown that out of this 20 percent, only two percent suffer from real intolerances.
What are the symptoms of intolerance?
Unlike allergies, intolerances are usually delayed. If you eat something that you can’t stand, symptoms can last for hours. This often makes it difficult to recognize intolerance and find out what is behind it.
Symptoms of intolerance are mainly in the gastrointestinal tract. Flatulence is especially unpleasant, but nausea, constipation, diarrhea and vomiting can also occur. Other possible symptoms:
- Headaches and migraines
- Wheezing and runny nose
Common food intolerances
Scientists today more or less well understand some types of intolerance. We know roughly what happens in the intestines and why the affected can no longer tolerate certain foods. Intolerance to lactose, fructose, sorbitol, histamine and celiac disease has been well studied.
Probably the most common milk sugar intolerance is lactose intolerance. Milk sugar lactose is found in milk and many dairy products. In Switzerland, lactose intolerance affects up to 20 percent of people. It is even more common in other regions, especially Asia. A specific enzyme that breaks down lactose is rarely found in the intestines. The body cannot process milk sugar properly, which leads to flatulence and abdominal pain.
Fructose and sorbitol intolerance
Those with fructose intolerance do not tolerate fructose. This gives the fruit a sweetness, but is also found in some vegetables. A transport protein transports fructose from the intestine to the blood. In the case of fructose intolerance, this transport protein does not work properly, there are problems using fructose – and symptoms from bloating and abdominal pain to fatigue and mood swings. Sorbitol intolerance is similar – here the intestines cannot properly process the sugar substitute sorbitol (Read more about fructose and sorbitol intolerance).
Gluten intolerance (celiac disease)
In celiac disease, gluten protein gluten triggers an immune response that leads to inflammation in the intestinal mucosa and therefore primarily to gastrointestinal complaints and, in the long term, to nutritional deficiencies and secondary diseases such as osteoporosis and anemia. Gluten is found in many types of grains, such as wheat, spelled and rye, as well as in many prepared foods – to the detriment of those affected who should eat completely gluten-free.
histamine intolerance is also called pseudoallergy. She has in common with food allergies that the messenger histamine leads to complaints such as redness of the skin, bloating, dizziness and runny nose. But while our immune cells secrete too much histamine in allergies, a certain enzyme that breaks down histamine from food is all too rare in the intestines and blood in those with histamine intolerance. Histamine-rich foods such as red wine, aged cheese, and dried sausages cause symptoms.
Symptoms of intolerance can also return to the psyche. For example, your brain may associate traumatic memories with certain foods. Sometimes the body reacts with psychosomatic symptoms when you eat again.
In addition to IgE antibodies, the immune system has other tools at its disposal, including IgG4 antibodies, G4 immunoglobulins. Our body also produces various IgG4 antibodies for all types of food we consume.
According to the theory, the production of certain IgG4 antibodies increases even more if we cannot tolerate food. This can lead to a variety of immune and inflammatory responses. There is an IgG4-mediated intolerance. Reactions and related complaints are delayed, sometimes only hours or days after you have eaten.
Checking IgG4 Values
IgG4 antibodies can be quantified using a blood test, such as a cerascreen® food reaction test. A large number of antibodies targeting a particular food may be a sign of intolerance.
Some researchers and societies criticize that the concentration of IgG4 allows making statements only about the extent of consumption of certain foods and has no clinical significance. This would indicate immune tolerance, not intolerance. To date, there has been no large-scale study investigating the relationship between IgG4 levels and food response.
Histamine, lactose, fructose and sorbitol intolerance and celiac disease cannot be detected with an IgG4 intolerance test. This requires different blood or breath tests.
How do I work with IgG4 test results?
An increase in IgG4 antibodies does not mean that you cannot tolerate food. However, you can eliminate from your diet for foods identified in the test and see if your symptoms improve. If the test shows a clear reaction to food, take it off the menu for two weeks. If your symptoms improve, this indicates possible intolerance. Then you can go without food for the next six months. After that, try to gradually bring it back into your diet.
An alternative is the so-called rotary diet. With this diet, you can skip several possible triggers of intolerance. To do this, eat only the foods you answered in the IgG4 test every four days. At the same time, your gut can repair itself. This rotation can already lead to a significant reduction in the number of complaints.
Food Reactions at a Glance
What is food allergy?
In the case of food allergies, our immune system fights off harmless proteins in food, so-called allergens. The mast cells of our immune system secrete histamine, which causes inflammation and complaints throughout the body.
What are the symptoms of a food allergy?
Food allergies can manifest through gastrointestinal complaints, itchy palates, and fluffy tongue. However, redness, itching and rashes on the skin and respiratory problems up to asthma are also common. In rare cases, a drop in blood pressure and anaphylactic shock may occur.
Which foods cause allergies?
In theory, many foods can cause allergies. In practice, however, several foods are responsible for over 90 percent of allergies. This includes cow’s milk, eggs, peanuts, tree nuts, soy, wheat, fish, and shellfish.
How to recognize food allergies?
If you suspect a food allergy, you can do a blood test, among other things. The test measures the amount of certain IgE antibodies in the blood. If the IgE value increases, antibody-associated food sensitization occurs. Then, temporarily avoid food to see if your symptoms go away.
What is food intolerance?
With intolerances, also called intolerances, symptoms do not arise from immune responses as in allergies. Instead, the gut often has problems processing certain food components, such as gluten, histamine, lactose, or fructose.
What are the symptoms of food intolerance?
Unlike food allergies, intolerances often do not occur immediately. Symptoms sometimes only appear after a few hours or days. Typical symptoms are gastrointestinal complaints, especially flatulence, headaches and migraines, runny nose, rash and fatigue.
What is IgG4-mediated food intolerance?
According to the theory, antibodies of the immune system IgG4 can be a sign of food intolerance. With IgG4 values in your blood sample, you can use skipping and alternating diets, which can eliminate intolerances and reduce symptoms.