Team:Linkoping Sweden/Knowledge Survey

Do you know nothing or nuthings?

A knowledge survey by LiU iGEM

LiU iGEM performed a survey to test the common knowledge about food allergies. The 330 participants were between 18-56 years old and students or employees at Swedish universities*. The survey was conducted in Swedish and spread by social media, mostly on Facebook.

Education

LiU iGEM predicted that participants with a university education including studies of the immune system or allergies and hypersensitivity, i.e. immunology or allergology, would have a greater knowledge about allergies than the ordinary student or employee. Participants were therefore asked whether their university education had included sections of these subjects. A quarter of the participants’ university educations had included sections of immunology or allergology.

How would you define allergy?

Participants were asked to define what an allergy actually is. Students and employees, who have not studied immunology or allergology defined allergy as an abnormal defense mechanism (67 %), inability to break down a certain substance (21 %), a cold linked to a certain stimuli (5 %), a food intolerance (3 %), hives and facial swelling (3%) or as a seasonal cold (1 %). Allergy definitions are summarized in Figure 1. Participants educated in immunology or allergology knows their subject and 95 % answered that an allergy is an abnormal defense mechanism.

An allergic reaction is indeed caused by the immune system, which is the main defense mechanism managing the protection against invading organisms, e.g. bacteria, viruses and parasites. These invading organisms are in many cases harmful and cause illness. An allergy is when the immune system mistakes an otherwise harmless substance as a dangerous intruder. The allergy inducing substances cause the immune system to overreact and produce Immunoglobin E (IgE) antibodies, which in their turn cause a chain reaction of cells releasing histamines and other chemicals leading to an allergic reaction and symptoms that commonly are associated with allergies, such as hives, facial swelling and other cold resembling symptoms1.

Inability to break down a certain substance is a more suitable description of one type of food intolerance caused by enzyme defects, e.g. lactose intolerance which is the inability to break down lactose, a type of sugar present in dairy products. Food intolerance, unlike food allergy, can have a number of different causes. Food allergy and food intolerance are both a type of food hypersensitivity and are commonly mistaken with each other, but there are some important differences. Food intolerance is not mediated by IgE antibodies in the immune system. Hence the much slower the onset of symptoms, which can be delayed for hours. The symptoms of food intolerance varies but the general symptoms include fatigue, joint pains, dark circles under the eyes, night sweats, diarrhea, vomiting, bloating and irritable bowel and some cases skin symptoms such as rashes and eczema. These symptoms may last for several hours, even days. The food allergy response, mediated by the immune system, is much more rapid and can be triggered by very small amounts of food. Those with food intolerance can tolerate a reasonable, not unlimited, amounts of the food.2

*Participants were students or employees at Linköping University (54 %), Örebro University (23 %), Karlstad University (6 %), Luleå University of Technology (5 %), Swedish University of Agricultural Sciences (5 %) or Chalmers University of Technology (2 %). A few participants were from the University of Gothenburg, KTH Royal Institute of Technology, Linnaeus University, Lund University, Stockholm University, Umeå University and Uppsala University. These participants were also included in the study, corresponding to a university answering ratio less than 1 % each.

Figure 1. Summarization of the common allergy definition. The survey showed that 67 % knows that allergies are caused by abnormalities in the immune system.

How common do you think nut or peanut allergies are?

In Sweden are 1 out of 20 children between 4 and 18 years old allergic to nuts or peanuts.I

4 % of the world population has some kind of food allergy, corresponding to the same number of people speaking Arabic, the world’s fifth most spoken language.II,III About the half of these allergies are to nuts or peanuts, which is just as many as live in Russia.III,IV

LiU iGEM wanted to know how common the society thinks that nut and peanut allergies actually are. In Sweden 1 out of 20 children between 4 and 18 years old are allergic to nuts or peanuts.3 43% of the participants, estimated that 5 % of the Swedish population 4-18 years old have nut or peanut allergy. While 33 % of the participants estimated it to be less common, 1 out of 100 children or less, and 24 % estimated that nut and peanut allergies are even more common, 1 out of 10 children or more. There was no significant difference in estimations made by those who have and have not studied immunology or allergology.

LiU iGEM aims to create awareness that nut and peanut allergy, actually are more common than many think. Food allergies over all are an increasing health issue in several countries in North America, Europe and Asia, and the number of children affected have been estimated to have doubled between the years of 1997 and 2011.4,5,6

Participants were asked whether they thought that nut and peanut allergies are more or less common globally than in comparison with solely Sweden. 66 % of the participants thought that the ratio of nut and peanut allergies in Sweden were above the global average, which was the correct conclusion. It has been estimated that 4 % of the world population has some kind of food allergy, but the prevalence of food allergies peak in the Western countries.7,8,9

Severity and symptoms

Participants were asked to identify the symptoms of anaphylaxis, a potentially life-threatening acute allergic reaction. Symptoms presented to the participants were hives, cardiac arrest, facial swelling, dizziness, stomach pains, elevated pulse and heart rate, runny nose, itching throat and breathing difficulties. All symptoms presented are symptoms of a more or less severe allergic reaction. The symptoms of anaphylaxis varies from person to person, but usually starts with an itching throat, followed by stronger symptoms such as swelling of the lips, stomach pains including vomiting and diarrhea, dizziness, chest pain and breathing difficulties. Severe anaphylaxis causes a drastic drop in blood pressure and elevation in heart rate which in its turn can lead to unconsciousness and cardiac arrest.10 The survey showed that it is rather common knowledge that anaphylaxis affects the respiratory tract and causes breathing difficulties. As well as that some of the first symptoms are swelling and itching of the face and throat. But it is rather few that know that the critical symptoms actually are those that affect the gastrointestinal and cardiovascular systems. It is important to understand the severity and recognize the symptoms of anaphylaxis. Answering ratios are summarized in Figure 2.

Figure 2. Summarization of answering ratios of participants asked to identify the symptoms of anaphylaxis, a potentially life-threatening acute allergic reaction.

True or false?

Participants were presented with a number of statements about nut and peanut allergies and asked to determine whether they are true or false. Figures show answering quotas of all participants.

Peanuts are closely related to cashews and pistachios

False: Peanuts resemble other nuts in terms of nutrition and taste, but in botany terms the peanut is a leguminous plant (Arachis hypogaea). The actual peanut is the plant seed that grows in the ground, hence the Swedish name jordnöt, directly translated to earth nut. The English name peanut indicates the close relationship to other legume plants, including peas as well as soy beans, beans and lentils.11 Some of those that are allergic to peanuts experience an allergic reaction when eating fruits from other legume plants. This occurs due to cross allergic reactions caused by peanut resembling substances found in closely related species.12

Hazelnuts, walnuts, Brazil nuts, cashews and pecans contain the same allergy inducing substance.

False: Unlike peanuts almonds, hazelnuts, walnuts, cashews, pecans, Brazil nuts, pistachios and macadamia nuts are defined as nuts according to the labeling rules of the European Union.13 Nut allergy is specific and most allergic individuals are usually allergic to only one type of nuts, i.e. hazelnut allergy or almond allergy, but since some nuts are more closely related than others cross allergic reactions do occur. E.g. Hazelnuts cross react with Brazil nut, walnut and pecans. It is very uncommon to be allergic to all types of nuts since all nuts do not contain the same allergy inducing substance and half of the participants did not know this.14

The more allergic reactions you have experienced, the greater risk for a severe allergic reaction.

False: The severity of an allergic reaction does not depend on the number of previous reactions. The most important factor of the severity is the dose. For those who previously have had severe symptoms after a small dose, a larger dose can in the future be devastating.15 However the very first time a body encounters a potentially allergy inducing substance no allergic reaction occurs and no symptoms are visible, but if the body mistakes the substance of being harmful it produce specific antibodies against the substance. The next time the body encounters the substance the reaction described in previous sections is activated by the specific IgE antibodies and certain cells of the immune system.16

Allergens are the substances that cause allergic reactions.

True: The scientific name of the allergy inducing substances, previously mentioned, is allergens. A substance that specifically binds to an antibody is called an antigen, hence the name allergens for antigens that binds to the antibodies that initiate the cascade of immunological events causing an allergic reaction.17 The most prevalent allergen in peanuts is Ara h 1, which is the substance detected by an antibody complex in LiU iGEM:s peanut detector.
   The survey showed that allergens are rather common knowledge.

There is a correlation between the severity of the allergic reaction and the amount of allergens.

True: Which symptoms that evolve during an allergic reaction depends on where in the body the histamine is released. Histamine is a hormone that has a key role in the cascade of events included in an allergic reaction and is released in response to allergens binding to IgE antibodies. A larger amount allergens thus increases the amount of histamines released and higher concentrations of histamine affect tissues in the gastrointestinal and respiratory tracts and blood vessels, causing the more severe symptoms.18

There are several documented deaths upon peanut intake.

True: Peanut allergy is not the most common food allergy, approximately 2 % of the world population, but it is the food allergy that causes the most number of deaths due to anaphylaxis.19 About 80% of the fatal anaphylaxis cases is caused by peanut or tree nut allergies.20

There are several documented life-threatening allergic reactions caused by airborne peanut allergy.

False: According to Magnus Wickman, a professor at Karolinska Institutet and children’s allergolog at the Sachsska children’s hospital in Stockholm, are there are no documented life-threatening allergic reactions caused by airborne allergens from peanuts or tree nuts known in the international society of specialized allergolists.15 LiU iGEM has not been able to find any situations that contradict this statement. Unlike what many may think food allergens are not gases that spread interminably in the air. Food allergens are small particles, we are talking about micrometers. Small particles settle slowly throughout the air. Allergens from tree nuts does not spread more than 1-2 meters. Peanuts can eventually spread a little bit longer. Frying and cooking as well as whipping and stirring increase the amount of allergens settling through the air but the air dilution is enormous and therefore a constant production of allergens is required to evoke severe symptoms. Someone eating peanuts from a bag or bowl is therefore luckily not sufficient enough.15

Stress/fear can influence an allergic reaction.

True: Experiencing allergic symptoms, such as itching and swelling of the throat, is uncomfortable and it is no wonder you get scared when it gets harder to breathe and it feels like you are going to suffocate. Fear and panic induce an allergic reaction even further, since the body’s stress response interacts with many of those organs and tissues affected during an allergic reaction.15,21

The critical symptoms of an allergic reaction are clearly visible directly after the food intake.

False: The first symptoms of an allergic reaction normally shows within a few minutes upon contact with the allergen. An allergic reaction usually culminates and reaches its climax within 10-30 minutes, but can under some rare circumstances be maintained for hours and days. However in most cases there is plenty of time to take the medications.10,15

You can experience allergic symptoms upon intake of peanuts without having true peanut allergy.

True: This phenomenon is known as a cross allergic reaction and occurs because proteins, including allergens, from different animals and plants resemble each other and the immune system is unable to tell them apart. Cross allergic reaction are especially common for those that have pollen allergies, which can make them hypersensitive to peanuts, tree nuts and drupes, such as apples, as well. Grass allergens are also known to cross react with peanuts and other legumes.22

Children normally outgrow their peanut allergy.

False: Peanut allergy is a chronic condition in the majority of cases, less than 20 % outgrow their allergy, And since the number of children affected have been more than doubled the last decade food allergies are indeed an increasing health issue.3,4,5,6

Common knowledge?

The final question of the “Do you know nothing or nuthings?” survey permitted the participants to estimate their own general knowledge about allergies. 68 % of the participants, who have not studied immunology or allergology, answered that their general knowledge about allergies is insufficient.

Thanks

LiU iGEM sends their gratitude to all participants and hopes you enjoyed it and hopefully learnt something on the way as well.

References