
Food Intolerances vs. Food Allergy - The Overview
What will you learn in this guide?
1. What's behind it?
2. Symptoms of food intolerance vs. allergy
3. Measures for recognition
4. The most known food intolerances
5. The most common food allergies
6. Pseudoallergy or real allergy?
7. Food supplement against intolerances and allergies
1. What's behind it?
Almost 20% of all Germans suffer from at least one allergy [1]. In short, an allergy, whether it is directed against food or pollen, is based on a malfunction of the immune system. In this case, the body perceives certain proteins, for example from peanuts, as a threat and initiates an immune reaction. Foods that are actually harmless can thus quickly become a danger!
It is not possible to say exactly how many people are actually affected by food intolerance. According to a survey, commissioned by SPIEGEL ONLINE (2450 people), 23% of people in Germany are affected [2]. In most cases, food intolerance is due to the absence or deficiency of certain enzymes responsible for digestion. Often, there is also an insufficient absorption capacity (limited absorption capacity) of certain food components. Therefore, in case of intolerance, there is a "dose-response threshold"! This means that small amounts of the food can usually still be tolerated, but the more that is ingested, the worse the symptoms become. In the case of an allergy, even small traces of the food can cause severe reactions [3].
2. Symptoms of food intolerance vs. allergy
The symptoms of a food intolerance can partly overlap with those of an allergy. In the case of an intolerance, however, redness and swelling do not occur directly after eating the food. As a rule, it is mainly various digestive complaints that become noticeable. Among other things, a bloated belly, abdominal pain, diarrhea, sluggishness, concentration problems, headaches and palpitations occur after eating. The symptoms can be triggered by even small amounts of the food.
In the case of an allergy, the first effects usually occur even with small amounts of the allergen. Swelling and redness to severe rashes immediately after eating the food are not uncommon. Because our esophagus and trachea are so close together, respiratory distress can occur so quickly. Headaches and fatigue are less common, but also possible. In the worst case, anaphylactic shock (life-threatening condition) can occur [4].

3. Measures for recognition
If it is suspected that an intolerance or allergy is present, it makes sense to keep a food diary. This enables you to trace back the foods that are the cause of the symptoms. If there is a concrete suspicion, the respective food should be consumed alone and not mixed with other food to be really sure!
It is important to start with small amounts and increase gradually to see whether the food or the amount of it leads to an intolerance. If you have already gained a rough overview through the food diary, you should definitely consult a doctor in order to clarify the exact causes. For example, problems that occur when drinking milk may be due to a lactose intolerance or a milk allergy. In order to initiate the right treatment, it must be clarified in advance what the diagnosis is.
4. The most known food intolerances
4.1 - Lactose intolerance
About 15% of all Germans [5] and 75% of the world population [6] are affected by lactose intolerance, i.e. have a low or absent production of the enzyme lactase. This enzyme breaks down the milk sugar lactose (a two-sugar) into glucose and galactose (both single sugars) to be absorbed in the small intestine for further energy production. If no or too little lactase is produced by the body, this is called lactose intolerance.
In intolerance, lactose enters the small intestine and has an osmotic effect, binding water to itself and causing diarrhea. Alternatively, it is fermented by bacteria in the intestine, forming gases, which causes flatulence and abdominal pain. If you still want to consume dairy products, you can either use lactose-free milk, long-matured cheese or the enzyme lactase. In case of a milk allergy, renunciation is unfortunately the only way!
The solution: milk alternatives
As already mentioned, if the milk intolerance is due to lactose intolerance, it is possible to use lactose-free milk or the enzyme lactase. If the milk intolerance is not due to a lactose intolerance, there are very many vegetable alternatives. Oat milk, almond milk, rice milk and soy milk are the most common alternatives, which you can make yourself or buy ready-made.
4.2 - Fructose intolerance
Fructose, colloquially known as fruit sugar, appears in two forms: as fructose (simple sugar) itself or as sucrose (household sugar). Sucrose consists of one molecule of fructose and one molecule of glucose and is broken down into both molecules in the small intestine.
In the case of intolerance, the problem is that the fructose cannot be absorbed by the small intestine or is absorbed in too small a quantity. As with lactose intolerance, the fructose enters the small intestine and can cause various complaints such as flatulence, abdominal pain, diarrhea and stomach cramps. This food intolerance has different gradations and often goes unnoticed for a long time!
4.3 - Saccharoseintoleranz (Zuckerunverträglichkeit)
Like lactose, sucrose (two-fold sugar) needs an enzyme (saccharase) to be broken down and then absorbed by the small intestine. If the enzyme is missing, the sucrose also enters the small intestine and can trigger symptoms similar to those of lactose intolerance.
4.4 - Sorbitol intolerance
The sugar alcohol sorbitol occurs naturally in fruits and is also sometimes used as a sugar substitute. The absorption of sorbitol into the small intestine may also be disturbed. The symptoms are similar to those of lactose, fructose and sucrose intolerance [7].
The solution: sugar alternatives
For people who do not tolerate fructose or table sugar, but do not want to give up sweetening their food, there are fortunately a variety of alternatives nowadays.
- Xylitol
Xylitol is also known as birch sugar. It is a sugar alcohol and is found in plants, such as birch, and in various fruits and even naturally in the human body. Its sweetening power is the same as sugar, but its calorie content is about 40% less. In addition, xylitol affects blood sugar and insulin levels less than table sugar. In addition, it cannot be metabolized by the bacteria that cause tooth decay. For this reason, xylitol is also the sweetener for our ActiNovo Plus flavored products [8]!
- Erythritol
- Rice syrup
- Stevia
This unusual plant from South America has been approved as a sweetener in the EU since 2011. It contains stevioglycosides responsible for the sweetness, which are 200-300 times sweeter than sugar. Since stevia is not metabolized, it has 0 calories and does not affect blood sugar levels. As a result, caries bacteria cannot do anything with it. Stevia is available in leaf form, as an extract or as pure stevioglycosides. Since it is heat-stable up to a temperature of 200 °C, stevia is very suitable for baking. The only disadvantage is that it has a taste of its own that takes some getting used to and can become bitter if consumed in excessive quantities [12].
4.5 - Gluten intolerance (celiac disease)
People who suffer from gluten intolerance can experience severe symptoms even from small amounts of the gluten protein or its component gliadin. Gluten is contained in wheat, spelt, rye, barley, but also in original varieties such as kamut, emmer and einkorn.
In the inflammatory bowel disease celiac disease (gluten intolerance), even minimal amounts of gluten can lead to an immunological reaction in the small intestine and damage the intestinal mucosa. In addition to digestive complaints, the most common symptoms include general fatigue, headaches and fatigue. If the intestine is exposed to gluten too often, the intestinal mucosa can be so severely damaged by chronic inflammatory processes that food components can no longer be properly absorbed through the intestinal mucosa into the blood. This damage can cause severe deficiency symptoms despite a nutrient-rich diet. In this case, the only way is to completely avoid foods containing gluten. For people who are particularly sensitive, there are products labeled gluten-free. These products (e.g. made from corn or rice) are processed exclusively in production facilities where no gluten-containing grain enters [13].
In some cases, there is also an intolerance to wheat. In these cases, more original cereals such as spelt, kamut, emmer and einkorn can usually be tolerated well. About 1% of all people are affected by celiac disease, although the typical symptoms are noticeable in only 10 to 20% [14]. Celiac disease can also be present without abdominal pain and nausea after eating.
The solution: wheat alternatives and gluten-free flours
Who does not tolerate wheat has nowadays many alternatives to not have to give up bread, pasta, cookies and cakes. There are flours from the following foods that can be used as a substitute or partial substitute for wheat flour: Oats, buckwheat, rice, corn, teff (millet), quinoa, amaranth. Nut flours such as almond flour or flours from legumes such as chickpea flour can also be used. To compensate for the lack of gluten properties of wheat flour, there are many alternatives such as chia seeds, flaxseed meal or psyllium husks.
And nowadays there are also many different types of pasta, such as rice, corn, buckwheat, lentil or pea noodles. Even ready-made cakes and cookies, as well as baking mixes, are now available as gluten-free products.
4.6 - Histamine intolerance
Histamine acts as a hormone and neurotransmitter in the human organism. It is produced when food ripens, but is also found in some fresh foods. If the body cannot produce enough enzymes to break down the histamine from food, histamine intolerance is present. After a meal, there is often redness of the skin, rashes, wheals, itching, a runny or stuffy nose, nausea, gastrointestinal problems, diarrhea, dizziness, headaches (including migraines), circulatory problems, and palpitations [15,16]. Since the histamine content in foods increases with storage time, it is recommended that affected individuals always consume fresh foods whenever possible. Nevertheless, a special diet must be followed and some foods must be completely avoided.
Foods rich in histamine include cheese, salami, chocolate, tomatoes citrus fruits and many more. Alcoholic beverages also contain histamine, but the amount is usually so small that people with histamine intolerance often do not experience any problems. The alcoholic beverage that contains the most histamine is red wine! [17].
5. The most common food allergies
As already mentioned, almost 20% of all Germans suffer from at least one allergy [18], which can basically be triggered by all kinds of substances. In extremely rare cases, people can even be allergic to water [19]. However, in the case of food allergies, there are 14 foods that are the most common allergens. These are eggs, peanuts, fish, crustaceans, gluten-containing cereals, nuts (mollusks), soy, lupins, sesame seeds, mustard, celery, cow's milk, sulfur dioxide, and sulfites [20]. Jewelry (nickel), textiles, disinfectants, animals, latex products, medications, and many other substances can also cause allergic reactions [21]. The allergens mentioned must be avoided, but thanks to a diverse range of alternatives, an individual solution is usually always possible.
6. Pseudoallergy or real allergy?
When allergy symptoms occur, it can also be a so-called pseudoallergy. In this case, the immune system reacts differently than in a real allergy and also does not form antibodies. Therefore, no correct diagnosis can be made via the conventional route (antibody test). Only by adding and omitting certain substances can the pseudoallergy be determined. In addition to many drugs, food additives are among the main triggers. Therefore, the best way to avoid such reactions is a natural diet with as few additives as possible [22].
Nut allergy
One of the most common food allergies is nut allergy. With this diagnosis it makes sense not to ban all nuts from the outset, but to test with which nuts the problem lies. If, for example, one cannot tolerate a nut mixture, it does not have to be due to all nuts, but can be caused by a certain type. The name nut does not always mean that botanically it is really a nut. Often, nuts, stone fruits and legumes also trigger the same reactions because they strongly resemble nuts. Therefore, we do not go into botanical terms further in the article and speak of nuts in general.
According to current studies, about 1.4% of the European population is affected by nut allergy [23]. Most frequently, an allergy to peanuts occurs. However, nuts such as hazelnuts, walnuts, almonds, cashews, pecans, macadamia nuts, Brazil nuts and pistachios are also frequently responsible for allergic reactions. Depending on the severity of the allergy, it must be decided whether it is sufficient to avoid the nuts or all products that may contain traces of nuts. It should also be considered that the oils of the respective nuts can also cause allergic reactions [24].

The solution: nut alternatives
However, in case of nut allergy, there are also alternatives to consume good fats and proteins. Seeds and seeds such as flaxseeds, chia seeds, sesame seeds, poppy seeds, sunflower seeds or pumpkin seeds are very similar in composition, but trigger allergies in far fewer cases. Hemp seeds, while botanically also nuts, have a lower allergen potential and are packed with good fats, proteins and minerals. Although both coconut and tiger nut have the word "nut" in their names, botanically they are not, and are well tolerated by most allergy sufferers [25]. If the alternatives are not suitable, olives and avocados are also good sources of fat to stay adequately supplied and maintain a healthy diet.
Spice allergy
Especially at Christmas time, spices such as cinnamon, vanilla, cardamom, anise, etc. are used to add a lot of flavor, but it's not just the nuts in the pastries that can be a problem for some allergy sufferers.
People who are allergic to certain pollens often also have a so-called cross-allergy. For example, birch pollen contains a protein that protects the pollen from bacteria. This protein is also present in foods such as apples, carrots and nuts [26]. If the body reacts allergically to it, as is the case with 70% of birch pollen allergy sufferers, this is known as a cross-allergy.
Unfortunately, this can also apply to certain spices, which can cause a cross-reaction depending on the type of pollen allergy. The classic gingerbread spice (as well as curry powder) contains a variety of allergens that overlap with those from many pollen. Therefore, caution is advised for pollen allergy sufferers! Those who have a pollen allergy and do not know, for example, whether they can tolerate gingerbread, should first try small amounts to rule out nausea and severe reactions [27].
7. Food supplement against intolerances and allergies
Since dietary supplements support many areas of life, the question now arises whether they also help with food intolerances and allergies. The answer is simple: yes.
Histamine plays a central role in the occurrence of allergic reactions. Fortunately, there are some nutrients that have been shown in various studies to lower histamine levels!
Quercetin - For allergy sufferers
Quercetin is a naturally occurring secondary plant compound from the flavonoid group. This promising nutrient with antioxidant activity is gaining increasing attention for the treatment of allergies. Many doctors see quercetin as a promising candidate to provide a natural alternative for allergy symptom relief in the future!
Study proves the effectiveness
In a Japanese study, Quercetin significantly inhibited antigen-stimulated histamine release. The effect of quercetin was almost twice as strong as that of sodium cromoglicate (conventional anti-hay fever agent) at the same concentration. This suggests that people suffering from swollen mucous membranes may benefit from quercetin [28]. One thing is certain: according to various studies, quercetin has a positive effect on the stabilization of the defense cells that are responsible for the release of histamine. The release of substances responsible for allergic reactions is reduced and both the symptoms and the allergic reaction itself are weaker. To achieve the best effect, preventive intake of quercetin is recommended two weeks before exposure to allergens [29,30].

Vitamin C - The all-rounder

A study at the University of Erlangen has also shown that C supply has a significant influence on serum histamine concentrations. In the study, patients suffering from both allergies and infectious diseases were administered a high dose of vitamin C intravenously, and a significant decrease in histamine concentration was subsequently observed. This was even greater in the patients with allergic diseases than in the patients with infectious diseases [34].
Vitamin D - The sunshine vitamin
For the immune system to function fully, an adequate supply of Vitamin D3 in the body is also essential. Vitamin D serves as a messenger for the control of our immune system, our human immune cells (B cells, T cells and antigen-presenting cells) all have vitamin D3 receptors. It is not for nothing that vitamin D can influence the innate adaptation of our immune response. Since the vitamin prevents the body from attacking itself because it cannot properly distinguish between its own and foreign cells, it is also called an immune modulator [35,36,37]. Deficiency of vitamin D is associated with increased autoimmunity and susceptibility to infections [38,39]. Even if opinions differ between official bodies and physicians, it is clear [40] that UV-B radiation in winter is too low for the organism to produce sufficient amounts of the vitamin on its own. In Germany, about 60% of the population is deficient in vitamin D according to international criteria, i.e. below 20 ng/ml in blood serum [41]. Many physicians even advocate that at least values between 40- 60 ng/ml should be achieved in the blood serum. Values up to 60 ng/ml are also considered safe in conventional, general medicine [42].

The trace element zinc
Furthermore, the immune system is influenced by the essential trace element Zinc. The relationship between zinc and the immune system is complex, as it influences in various ways. It acts as an important cofactor in more than 300 enzymes, as well as for the immune system. One of these enzymes that relies on zinc is the enzyme DAO (diamine oxidase), which is involved in the breakdown of histamine in the body [43,44].
So it's no wonder why many doctors recommend that allergy sufferers have their zinc status checked. A zinc deficiency can severely impair the resistance of the immune system. Even a minor deficiency can have an impact on the immune system, which is why increased zinc intake is recommended in cases of acute deficiency [45,46,47,48]. The composition of the diet, the prevailing age, and the health status influence zinc absorption, which is why it is not possible to make a blanket statement as to whether a deficiency exists.
In Germany, 32% of men and 21% of women do not reach the recommended D-A-CH reference values for daily zinc intake. In the age group of 65 to 80 years, it is even 44% of men and 27% of women [49]. Brittle nails with white spots and grooves, for example, are a strong indication of a deficiency [50]. Anyone who suspects that their allergy symptoms are related to a zinc deficiency should have their zinc levels checked to prevent deficiency situations.