UNIT 1 - FOOD ALLERGIES AND FOOD INTOLERANCE |
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Food allergies Food intolerance
Video review |
OBJECTIVES:
- Discuss common causes of food allergies.
- Identify symptoms of allergies and food intolerance.
- Understand the advantage and disadvantage of avoiding foods with gluten.
- Neal Barnard, MD (2009). Nutrition Guide for Clinicians.
- Michael Greger, MD (2011). Nutrition Facts.
- Monika Petruláková, Ľubomír Valík (2015). Department of Food Nutrition and Assessment, Institute of Biochemistry, Nutrition and Health Protection, Slovak University of Technology.
Food Allergies
Food allergy is defined as an adverse immunological (hypersensitivity) response to food (food proteins) and as such it is not a single disease, nor is it caused by one pathophysiologic disturbance. This is manifested only in hypersensitive individuals , who have so-called predisposition and where symptoms appear rapidly following exposure to macromolecules . Food allergic reaction can be divided into IgE mediated and non IgE mediated.
The number of patients suffering from food allergy has increased during recent decades, and allergic diseases have become a major clinical and public problem. There are several factors, which are responsible for development of food allergy: especially genetic allergy predisposition, early “foreign” food protein exposure (time, dose, and frequency), allergen uptake and handling. The prevalence of specific food allergies is dependent on regional dietary habits and methods of food preparation.
The risk of developing allergies is significantly influenced by genetic disposition. The changes in lifestyle and environmental factors result in increases of adverse food reactions. Complex factors include socio-economic impacts, impacts of external and internal environment, exposure to new allergens, stress, use of antibiotics, infectious diseases, climate change, and others.
Food allergy affects 2—4 % of the population. The highest prevalence observed in children between 1.5 to 3 years (25 % of all food reactions). According to various studies suffer from food allergy 6—8 % of children and 1—2 % of adults. Only about 20% of all food allergies persist into adulthood, others resolve spontaneously within three years of age. This is probably due to delayed onset of the mechanisms of oral tolerance to food proteins. Some studies indicated only 11 % resolved egg and 19 % resolved milk allergy by age 4 years.
Symptoms range from mild and tolerable (slight abdominal pain) to anaphylaxis which can result in physical collapse and death. The symptoms are divided into three main groups: immediate (within 1h of ingestion), delay or late (more than 1h after ingestion), and remote. Symptoms may involve the skin, gastrointestinal tract, respiratory tract, the motoric system, cardiovascular system, genitourinary tract and central nervous system, or can be shown by overall reaction (life threatening anaphylactic reaction — in rare instances) as shown in the table below.
The number of patients suffering from food allergy has increased during recent decades, and allergic diseases have become a major clinical and public problem. There are several factors, which are responsible for development of food allergy: especially genetic allergy predisposition, early “foreign” food protein exposure (time, dose, and frequency), allergen uptake and handling. The prevalence of specific food allergies is dependent on regional dietary habits and methods of food preparation.
The risk of developing allergies is significantly influenced by genetic disposition. The changes in lifestyle and environmental factors result in increases of adverse food reactions. Complex factors include socio-economic impacts, impacts of external and internal environment, exposure to new allergens, stress, use of antibiotics, infectious diseases, climate change, and others.
Food allergy affects 2—4 % of the population. The highest prevalence observed in children between 1.5 to 3 years (25 % of all food reactions). According to various studies suffer from food allergy 6—8 % of children and 1—2 % of adults. Only about 20% of all food allergies persist into adulthood, others resolve spontaneously within three years of age. This is probably due to delayed onset of the mechanisms of oral tolerance to food proteins. Some studies indicated only 11 % resolved egg and 19 % resolved milk allergy by age 4 years.
Symptoms range from mild and tolerable (slight abdominal pain) to anaphylaxis which can result in physical collapse and death. The symptoms are divided into three main groups: immediate (within 1h of ingestion), delay or late (more than 1h after ingestion), and remote. Symptoms may involve the skin, gastrointestinal tract, respiratory tract, the motoric system, cardiovascular system, genitourinary tract and central nervous system, or can be shown by overall reaction (life threatening anaphylactic reaction — in rare instances) as shown in the table below.
Location |
Manifestation |
Gastrointestinal |
Abdominal cramps, flatulence, blood in the stools, nausea, abdominal distension, colic, pain, vomiting, meteorism, diarrhea, constipation, malabsorption. |
Skin |
Atopic dermatitis, contact dermatitis, eczema, skin rashes, itching or flushing, tingling, swelling of the lips, palate, tongue or throat erythema, urticaria, angioedema |
Respiratory |
Recurrent wheezing, nasal congestion, itchiness or sneezing, asthma, laryngeal edema, stridor, cough, rhinoconjunctivitis, shortness of breath dyspnea |
Mouth, neck, ears |
stomatitis, otitis, pharyngitis |
Nervous system |
irritability, restlessness, fatigue, migraine |
Blood count |
anemia, eosinophilia, thrombocytopenia |
Other signs |
enuresis, nephrotic syndrome, arthritis |
Symptoms of food allergy vary depending on several factors, such as the age of the subject, the allergen involved and the amount of food eaten, physical exercise, stress, coexisting medical problems, among others. The food allergens can be defined as chemical, physical and biological substances occurring in environmental, which in sensitive individuals produce allergic reactions. The ability of allergen provoke this reaction depends on the type of allergen, the amount, duration of operation, points of entry and the degree of hypersensitivity of a particular organism. The allergic reaction can be caused by different amount of protein, from perhaps a tenth of a milligram up to grams, and sometimes tens of grams.
The major food allergens are water- or salt-soluble proteins or glycoproteins with molecular weights of 10—60 kD that are stable to heat, acid, and proteases . Allergens, which are stable against denaturation and degradation during food processing, are mostly responsible for causing food allergies.
The major food allergens are water- or salt-soluble proteins or glycoproteins with molecular weights of 10—60 kD that are stable to heat, acid, and proteases . Allergens, which are stable against denaturation and degradation during food processing, are mostly responsible for causing food allergies.
More than 200 proteinaceous allergens have been identified and characterized, and over 100 different foods or food components may cause adverse reactions. The eating habits and sociocultural background are responsible for differences in foods most commonly involved in allergy. Variations of occurrence are between age groups as well as countries. The main allergens, which according to recommendation of European Union subject to mandatory marking on the food are:
These so-called main allergens are responsible for almost 90 % of allergic reactions and intolerance. Reactions to fruits (apples, peaches, apricots, cherries, kiwi and citrus fruits) and vegetables (celery) are common (approximately 5 %) but usually not severe and the allergens are often sensitive to cooking. Also, some food additives — colours, preservatives, flavorings, colorings, antioxidants, can be implicated in food allergies and intolerances. It is generally assumed that sensitization to the classical food allergens such as milk, egg, peanut and fish occurs via the gastrointestinal tract, although other types of food allergy occur as a consequence of prior sensitization to inhaled allergens such as pollen.
Cereals are the major plant food, which cause adverse food allergies. Cereals contain a range of allergens. IgE mediated reactions to wheat have been demonstrated as early as the beginning of the 20th century. The prevalence of cereal allergy has increased among the children as well as among the adults. More than 0.5 % of children and 3 % of adults suffer from an allergy to wheat. Some cereal allergens: water soluble albumins and globulins (lipid transfer proteins, inhibitors of trypsin and α-amylase), and water insoluble gliadins and glutenins, known as prolamins were described in scientific studies.
From the animal origin foods, milk is the food, which is often responsible for formation of allergies. Cow’s milk is one of the most common causes of adverse reactions in foods and it contains about 20 proteins, which are considered to be an allergens. Allergy is frequently induced by casein and whey proteins. Casein is fractionated into α-, β-, and κ-casein. Whey proteins include: α-lactalbumin (α-la), β-lactoglobulin (β-lg), bovine serum albumin (BSA) and immunoglobulin (Igs). The most common allergens are β-lactoglobulin, α-casein and serum albumine. Allergy to cow milk can be observed in about 2.5 % of children below 3 years of age.
- cereals containing gluten (i.e. wheat, rye, barley, oats, spelt, kamut or their hybridised strains)
- crustaceans
- eggs
- fish
- peanuts
- soybeans
- milk
- nuts (almond, hazelnut, walnut, cashew, pecan nut, Brazil nut, pistachio nut, Macadamia nut and Queensland nut)
- celery
- mustard
- sesame seeds
- sulphur dioxide and sulphites at concentrations of more than 10 mg/kg or 10 mg/litre expressed as SO2 (DIRECTIVE 2003/89/EC).
These so-called main allergens are responsible for almost 90 % of allergic reactions and intolerance. Reactions to fruits (apples, peaches, apricots, cherries, kiwi and citrus fruits) and vegetables (celery) are common (approximately 5 %) but usually not severe and the allergens are often sensitive to cooking. Also, some food additives — colours, preservatives, flavorings, colorings, antioxidants, can be implicated in food allergies and intolerances. It is generally assumed that sensitization to the classical food allergens such as milk, egg, peanut and fish occurs via the gastrointestinal tract, although other types of food allergy occur as a consequence of prior sensitization to inhaled allergens such as pollen.
Cereals are the major plant food, which cause adverse food allergies. Cereals contain a range of allergens. IgE mediated reactions to wheat have been demonstrated as early as the beginning of the 20th century. The prevalence of cereal allergy has increased among the children as well as among the adults. More than 0.5 % of children and 3 % of adults suffer from an allergy to wheat. Some cereal allergens: water soluble albumins and globulins (lipid transfer proteins, inhibitors of trypsin and α-amylase), and water insoluble gliadins and glutenins, known as prolamins were described in scientific studies.
From the animal origin foods, milk is the food, which is often responsible for formation of allergies. Cow’s milk is one of the most common causes of adverse reactions in foods and it contains about 20 proteins, which are considered to be an allergens. Allergy is frequently induced by casein and whey proteins. Casein is fractionated into α-, β-, and κ-casein. Whey proteins include: α-lactalbumin (α-la), β-lactoglobulin (β-lg), bovine serum albumin (BSA) and immunoglobulin (Igs). The most common allergens are β-lactoglobulin, α-casein and serum albumine. Allergy to cow milk can be observed in about 2.5 % of children below 3 years of age.
Food Intolerance
Food intolerance Food intolerance is abnormal non-immune reaction with allergy-like symptoms after ingesting of food . It results from enzyme deficiencies, pharmacological reactions, and response to toxic or irritant components of food . Estimates of the prevalence of food intolerance vary widely from 2 % to over 20 % of the population. The prevalence of food intolerance in adults are no more than 5—6 %, in infants and young children is varying from 0,3 % to 20 %.
Symptoms of food intolerance include skin rashes, urticaria, angioedema and eczema, nasal congestion, sinusitis, pharyngeal irritations, asthma and an unproductive cough, mouth ulcers, abdominal cramp, nausea, gas, intermittent diarrhea, constipation, irritable bowel syndrome, and may include anaphylaxis.
LACTOSE INTOLERANCE
Intolerance to lactose The lactose intolerance is a result of lactase deficiency and is a form of carbohydrate malabsoption. Lactose is hydrolyzed by lactase in the intestinal mucosa. The by-products of lactose hydrolysis are the monosacharides, glucose and galactose. The lactase deficiency has been described as primary, secondary, or congenital ones.
Primary lactase deficiency is the normal gradual reduction in lactase production seen as an individual matures from infancy into adulthood and is expressed variably across populations. Approximately 25 % of the human population maintains a high level of lactase activity and therefore a large capacity to digest lactose throughout life. Secondary lactase deficiency occurs because of gastroenteritis, bowel surgery, cystic fibrosis, or immune disorders. Congenital lactase deficiency is a rare hereditary disorder in which lactase activity is absent.
The prevalence of lactose intolerance is lowest in people of Northern European descent (15 %) and highest in many Asian populations (near 100 %). The prevalence lactase deficiency in individuals of African descent is approximately 70—80 %. Similar level is reported for Latinos and those of Eastern and South American ancestry.
The symptoms of lactose intolerance include, for example flatulence, loose, stools, abdominal pain, diarrhea, vomiting, skin irritation. Not all individuals with a reduce level of the enzyme lactase exhibit symptoms with the ingestion of dietary lactose. The presence or absence of symptoms varies with amount and type of food consumed, intestinal transit time, and the level of residual intestinal lactase.
GLUTEN INTOLERANCE
Intolerance to gluten Gluten is a protein, which is rich in amino acids proline and glutamine. These amino acids are collectively known as prolamins. Gluten is found mainly in foods (wheat, rye and barley) but may also be found in everyday products such as drugs or vitamins. Consumption of gluten can lead to development of celiac disease (gluten enteropathy) in subjects with genetic predisposition. It causes inflammation of the small intestine, leads to numerous abdominal as well as non-gastrointestinal symptoms and interferes with absorption of nutrients from food.
CELIAC DISEASE
Celiac disease has a four sub-phenotype: — classic celiac disease — dominated by symptoms and sequelae of GI malabsorption, — celiac disease with atypical symptoms — few or no GI symptoms, extraintestinal symptoms predominate — silent celiac disease — patients are asymptomatic but have a positive serologic test — latent celiac disease — persons are asymptomatic but are at increased risk for later development of symptoms and/or histologic changes.
Celiac disease (CD) affects 1 % of the children and adults in the United States and Europe with similar prevalence rates in many other countries worldwide. Symptoms of celiac disease occur when dietary proteins in wheat, barley, and rye are ingested by susceptible patients, activating an abnormal mucosal immune response that damages the small intestine by inducing chronic inflammation. The most common gastrointestinal (GI) symptoms of celiac disease include diarrhea, weight loss, vomiting, abdominal pain (with or without distention), anorexia, and constipation.
The most common non-GI symptoms include iron-deficiency anemia (up to 5 % of celiac patients are anemic), failure to grow, short stature, delayed puberty, infertility, recurrent fetal loss, osteoporosis, vitamin deficiencies, fatigue, protein-calorie malnutrition, recurrent aphthous stomatitis, elevated transaminase levels, and dental enamel hypoplasia. The presence of obesity does not preclude a diagnosis of celiac disease. Several neuropsychiatric conditions have been reported to accompany celiac disease, including depression, anxiety, ataxia, seizures, peripheral neuropathies, and migraines.
Symptoms of food intolerance include skin rashes, urticaria, angioedema and eczema, nasal congestion, sinusitis, pharyngeal irritations, asthma and an unproductive cough, mouth ulcers, abdominal cramp, nausea, gas, intermittent diarrhea, constipation, irritable bowel syndrome, and may include anaphylaxis.
LACTOSE INTOLERANCE
Intolerance to lactose The lactose intolerance is a result of lactase deficiency and is a form of carbohydrate malabsoption. Lactose is hydrolyzed by lactase in the intestinal mucosa. The by-products of lactose hydrolysis are the monosacharides, glucose and galactose. The lactase deficiency has been described as primary, secondary, or congenital ones.
Primary lactase deficiency is the normal gradual reduction in lactase production seen as an individual matures from infancy into adulthood and is expressed variably across populations. Approximately 25 % of the human population maintains a high level of lactase activity and therefore a large capacity to digest lactose throughout life. Secondary lactase deficiency occurs because of gastroenteritis, bowel surgery, cystic fibrosis, or immune disorders. Congenital lactase deficiency is a rare hereditary disorder in which lactase activity is absent.
The prevalence of lactose intolerance is lowest in people of Northern European descent (15 %) and highest in many Asian populations (near 100 %). The prevalence lactase deficiency in individuals of African descent is approximately 70—80 %. Similar level is reported for Latinos and those of Eastern and South American ancestry.
The symptoms of lactose intolerance include, for example flatulence, loose, stools, abdominal pain, diarrhea, vomiting, skin irritation. Not all individuals with a reduce level of the enzyme lactase exhibit symptoms with the ingestion of dietary lactose. The presence or absence of symptoms varies with amount and type of food consumed, intestinal transit time, and the level of residual intestinal lactase.
GLUTEN INTOLERANCE
Intolerance to gluten Gluten is a protein, which is rich in amino acids proline and glutamine. These amino acids are collectively known as prolamins. Gluten is found mainly in foods (wheat, rye and barley) but may also be found in everyday products such as drugs or vitamins. Consumption of gluten can lead to development of celiac disease (gluten enteropathy) in subjects with genetic predisposition. It causes inflammation of the small intestine, leads to numerous abdominal as well as non-gastrointestinal symptoms and interferes with absorption of nutrients from food.
CELIAC DISEASE
Celiac disease has a four sub-phenotype: — classic celiac disease — dominated by symptoms and sequelae of GI malabsorption, — celiac disease with atypical symptoms — few or no GI symptoms, extraintestinal symptoms predominate — silent celiac disease — patients are asymptomatic but have a positive serologic test — latent celiac disease — persons are asymptomatic but are at increased risk for later development of symptoms and/or histologic changes.
Celiac disease (CD) affects 1 % of the children and adults in the United States and Europe with similar prevalence rates in many other countries worldwide. Symptoms of celiac disease occur when dietary proteins in wheat, barley, and rye are ingested by susceptible patients, activating an abnormal mucosal immune response that damages the small intestine by inducing chronic inflammation. The most common gastrointestinal (GI) symptoms of celiac disease include diarrhea, weight loss, vomiting, abdominal pain (with or without distention), anorexia, and constipation.
The most common non-GI symptoms include iron-deficiency anemia (up to 5 % of celiac patients are anemic), failure to grow, short stature, delayed puberty, infertility, recurrent fetal loss, osteoporosis, vitamin deficiencies, fatigue, protein-calorie malnutrition, recurrent aphthous stomatitis, elevated transaminase levels, and dental enamel hypoplasia. The presence of obesity does not preclude a diagnosis of celiac disease. Several neuropsychiatric conditions have been reported to accompany celiac disease, including depression, anxiety, ataxia, seizures, peripheral neuropathies, and migraines.
Article Review
Hypersensitivity reactions to food and drug additives: problem or myth?
Allergens of Animal Origin: Stability and Allergenicity of Processed Foods
Gluten-free diet in non-celiac patients: beliefs, truths, advantages and disadvantages
Allergens of Animal Origin: Stability and Allergenicity of Processed Foods
Gluten-free diet in non-celiac patients: beliefs, truths, advantages and disadvantages
Video Review
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Unit Task
Submit your Reflective Journal after watching the videos, reading the lesson and article.