1. Trends in Allergies and Intolerances in Nutrition and Food Service
Janice M. Joneja, Ph.D., RD
10th Annual Regional Nutrition and Food Service Conference
Edmonton 2006

2. Progress in the Past 5 Years
Nearly 4% of North Americans have food allergies, many more than recorded in the past
Incidence of food allergy much higher in children than adults (>8% compared to <2%)
Prevalence of peanut allergy doubled in American children younger than 5 years of age in the past 5 years
Incidence of food intolerances estimated to be up to 50% of the population, but accurate figures are not available because of the lack of appropriate tests
Incidence of food intolerances much higher in adults than in children
Many food allergens have been characterized at the molecular level, leading to increased understanding of the causes of many allergic disorders

3. Management of Food Allergies and Intolerances
Management of food sensitivities consists of:
Accurate identification of the food causing the problem
Educating clients on how to avoid relevant allergens and intolerance triggers in foods
Formulating appropriate diets to avoid the culprit foods and replacing them with foods of equivalent nutritional value
Educating parents in measures to avoid sensitization of their at-risk babies

4. The Allergic Diathesis
Atopic dermatitis
(Eczema) .
Sleep deprivation
Irritability
Gastrointestinal
symptoms
Food Allergy
Mental fogginess
Fatigue
Asthma
(cough;
wheeze)
Allergic rhinoconjunctivitis
(hay fever)
Anaphylaxis

5. Response of the Immune System
Food Allergy
Response of the Immune System

6. Priority Food Allergens In Canada
Peanuts
Tree nuts (almonds, Brazil nuts, cashews, hazelnuts (filberts), macadamia nuts, pecans, pinenuts, pistachios, walnuts)
Sesame seeds
Milk
Eggs
Fish
Shellfish (e.g. clams, mussels, oysters, scallops and crustaceans (e.g. crab, crayfish, lobster, shrimp) )
Soy
Wheat
Sulphites
These Priority Allergens account for more than 95% of severe adverse reactions related to food allergens

7. Additional Factors Involved in Symptoms of Food Sensitivity
Increased permeability of the digestive tract
(leaky gut)
Inflammation:
Infection
Allergy
Autoimmune disease
Other diseases
Immaturity (in infants)
Alcohol consumption
Physical exertion:
Exercise-induced anaphylaxis

8. Additional Factors Involved in Symptoms of Food Sensitivity
Stress
Eating several different allergenic foods at the same time
Other allergies occurring at the same time (e.g. hay fever, asthma)

9. Classification of Food Allergens [Sampson 2003]:
Direct sensitization via the gastrointestinal tract after ingestion
Water-soluble proteins or glycoproteins
Stable to heat, proteases, and acid
Many are lipid transfer proteins
Class 2:
Sensitization by inhalation of air-borne allergen
Cross-reaction to foods containing structurally identical proteins
Heat labile
Many are pathogenesis-related proteins

10. Oral Allergy Syndrome (OAS)
OAS refers to clinical symptoms in the mucosa of the mouth and throat that:
Result from direct contact with a food allergen
In an individual who also exhibits allergy to inhaled allergens.
Usually pollens (pollinosis) are the primary allergens
Pollens usually trigger rhinitis or asthma
Occurs most frequently in adults

11. Oral Allergy Syndrome Characteristics
Inhaled pollen allergens sensitize tissues of the upper respiratory tract
Tissues of the respiratory tract are adjacent to oral tissues, and the mucosa is continuous
Sensitization of one leads to sensitization of the other
OAS symptoms are mild in contrast to primary food allergens and occur only in and around the mouth and in the throat

12. Oral Allergy Syndrome
The foods cause symptoms in the oral cavity and local tissues immediately on contact:
Swelling
Throat tightening
Tingling
Itching
“Blistering”
Foods most frequently associated with OAS are mainly fruits, a few vegetables, and nuts

13. Oral Allergy Syndrome Allergens
Pollens and foods that cause OAS are usually botanically unrelated
Occurs most frequently in persons allergic to birch and alder pollens
Also occurs with allergy to:
Ragweed pollen
Mugwort pollen
Grass pollens

14. Oral Allergy Syndrome Cross-reacting allergens
Birch pollens with:
Apple
Stone Fruits (Apricot, Peach, Nectarine, Plum, Cherry)
Kiwi Fruit
Orange Peanut - Almond
Melon Hazelnut - Walnut
Watermelon Carrot - Anise
Potato - Celery - Caraway seed
Tomato Parsnip
Green pepper - Parsley
Cumin - Beans
Coriander - Peas
Dill - Lentils
Sunflower seed - Soy

15. Oral Allergy Syndrome Cross-reacting allergens
Ragweed pollen with:
Banana
Cantaloupe
Honeydew
Watermelon
Other Melons
Zucchini (Courgette)
Cucumber

16. Expression of OAS Symptoms
Oral reactivity to the food significantly decreases when food is cooked
Reactivity of the antigen depends on ripeness
Antigen becomes more potent as the plant material ages
People differ in the foods which trigger OAS, even when they are allergic to the cross-reacting pollens
Foods contain an antigen that is structurally similar to the allergenic pollen, but not all people will develop OAS to all foods having that antigen

17. Identification of Foods Responsible for OAS Symptoms
Skin tests will identify the allergenic plant pollen
Skin testing has not been successful in identifying persons who react to cross-reacting food antigens
Plant antigens are unstable and do not survive the process of antigen preparation
Crushing plant material leads to release of phenols and degradative enzymes
Prick + prick technique are more reliable than standard skin tests
Lancet is inserted in raw fruit or vegetable, withdrawn and then used to prick the person’s skin

18. Latex-Fruit Syndrome Allergy to latex often starts as:
Contact allergy to a latex protein, usually through:
Abraded (non-intact) skin
Mucous membrane
Exposed tissue (e.g. during surgery)
Inhalant allergy:
Inhaled powder from latex gloves

19. Latex Allergy Cross-reacting allergens
As antigen comes into contact with immune cells, repeated exposure leads to IgE mediated allergy
Proteins in foods with the same structure as proteins in latex trigger the same IgE response when they are eaten
In extreme cases can cause anaphylactic reaction

20. Latex Allergy Related foods
Examples of foods that have been shown to contain proteins similar in structure to latex:
Banana - Mango - Tomato
Citrus Fruits Melon - Celery
Kiwi Fruit Pineapple - Avocado
Fig Papaya - Tree Nuts
Passion Fruit - Peach Chestnut
Grapes - Potato - Peanut

21. Common allergens in unrelated plant materials: Summary
OAS and latex allergy are examples of conditions in which common antigens, expressed in botanically unrelated plants, are capable of eliciting a hypersensitivity reaction
In practice, when a specific plant food elicits an allergic response, foods in the same botanic family rarely elicit allergy

22. Biochemical and Physiological Responses
Food Intolerances
Biochemical and Physiological Responses

23. Symptoms of Carbohydrate Intolerance
Watery loose stool (diarrhea)
Abdominal bloating and pressure
Cramping pain in abdomen
Flatulence
Vomiting
Poor weight gain

24. Cause of Carbohydrate Intolerance
Lack of the enzyme that digests the carbohydrate
Lactose intolerance is due to the lack of lactase:
Milk sugar (lactose) is not digested
Sucrose intolerance is lack of the enzyme sucrase
Sucrose (table sugar; syrup of all types; some fruits) is not digested

25. Symptoms of Carbohydrate Intolerance
Reddening and soreness of skin around the anus and on the buttocks due to acid (pH less than 6) stool in children.
Adults rarely develop high acid stool
Abdominal fullness, bloating, and cramping within 5-30 minutes after eating
Diarrhea
Lactose intolerance is the most common condition

26. Management of Lactose Intolerance
Only the milk sugar, lactose, needs to be avoided
This is not a milk allergy:
Milk proteins are tolerated
Lactose occurs in the whey (liquid) fraction of milk
Milk products free from lactose and free from whey are safe
These foods include:
Milk treated with lactase (Lactaid; Lacteeze)
Hard cheeses (whey is removed; casein remains and is fermented to form cheese)
Many people tolerate yogurt, where lactose is broken down by bacterial enzymes

27. Reactive Chemicals in Foods
May act on the body in two ways:
chemical acts directly on body tissues rather like a drug
chemical reacts with a system (stops or enhances the process) that acts on the body tissue
Symptoms occur when the body is unable to get rid of the chemical quickly enough
The level in the body rises and the symptoms that develop are due to the excess

28. Histamine
Histamine reactions can be clinically indistinguishable from food allergy
Hives, facial swelling, and headaches are examples of histamine excess
Tests for food allergy are usually negative
Histamine sensitivity is becoming recognized as a disease entity quite distinct from allergy
Sensitivity may be deficiency in the enzymes that break down excess histamine
Histamine intolerance can exacerbate allergy to the extent of eliciting an anaphylactic reaction when the two conditions occur together

29. Sources of Histamine in Foods
Fermented foods:
Microbial activity on proteins produces histamine
Examples:
Cheese
Processed meats and sausages:
Salami
Bologna
Pepperoni
Vinegar and foods containing vinegar:
Pickles

30. Sources of Histamine in Foods
Fermented beverages:
Wine
Beer, ale, lager
Fish and shellfish:
Incorrectly stored
Bacteria in the intestine of the fish start to break down fish protein

31. Sources of Histamine in Foods
Some foods contain high levels of histamine naturally, especially:
Spinach
Eggplant
Berries (strawberries and raspberries)
Tomato
Citrus fruits (orange; lemon; lime; grapefruit)
Some foods may release histamine by a mechanism which is only partially understood
example: egg white

32. Other Sources of Histamine
Micro-organisms in the body:
Certain types of bacteria in the large bowel use undigested food material for their reproduction and growth
People with these micro-organisms absorb histamine from their own intestine
It is possible that probiotic bacteria could be used to displace these strains

33. Tyramine sensitivity Symptoms when tyramine-rich foods are eaten:
Sharp rise in blood pressure
Headache
Caused by:
Deficiency in the enzymes that break down excess tyramine

34. Tyramine in Foods Formed by microbial action in food preparation:
cheese
wine
yeast extract
vinegar
Small amounts occur naturally in some foods:
chicken liver - eggplant
avocado - tomato
banana - plum

35. Sensitivity to Food Additives
Characteristics common to persons sensitive to food additives:
History of asthma and hay fever
Occasionally hives and facial swelling
Aspirin sensitive

36. Additives Most Frequently Causing Intolerances
Tartrazine (and other artificial food colours)
Preservatives:
Sulphites
Benzoates
Sorbates
Monosodium glutamate (MSG)
Nitrates and nitrites

37. Symptoms of Tartrazine Sensitivity
Asthma in asthmatics
Urticaria
Angioedema
Nausea
Migraine headaches
Evidence of hyperactivity in children
Excess tartrazine may increase levels of inflammatory mediators in allergy, such as:
leukotrienes – important mediators in asthma
histamine

38. Foods Frequently Containing Tartrazine
Soft drinks
Liqueurs and cordials
Candy and confectionery
Ready-to-eat cereals
Jams and jellies
Ice cream, sherbet, milk shakes
Commercial gravies and soup mixes
Flavor packets
Pickles, relish, salad dressings
Prepared baked goods
Smoked fish and fish products

39. Foods Frequently Containing Tartrazine
Snack foods
Meal replacements
Any food containing “artificial color” may contain tartrazine unless it is labeled “tartrazine free”
Non-food items:
Medications (prescription and OTC)
Vitamin and mineral supplements
Toiletries and cosmetics

40. Sulphite Sensitivity Most common in asthmatics
Steroid-dependent asthmatics are most at risk
Adverse reactions to sulphites is estimated to be as high as 1% of the U.S. population
Sulphite sensitivity in non-asthmatics is considered to be quite rare
Symptoms occur in most organ systems:
Lungs
Gastrointestinal tract
Skin and mucous membranes
Life-threatening anaphylactic reactions in asthmatics have been recorded, but occur very rarely.

41. Symptoms Reported in Sulphite Sensitivity
Urticaria (hives)
Angioedema (swelling, especially of the mouth and face)
Contact dermatitis
Anaphylaxis (in asthmatics)
Anaphylactoid reaction (non-asthmatics)

42. Forms of Sulphites Permitted in Foods
Sulphites are permitted in the form of:
Sodium metabisulphite
Potassium metabisulphite
Sodium bisulphite
Potassium bisulphite
Sodium sulphite
Sodium dithionite
Sulphurous acid
Sulphur dioxide

43. Forms of Sulphites Permitted in Foods
Use of sulphites on fresh fruits and vegetables not allowed except on sliced raw potatoes and raw grapes
Sulphites are not allowed on raw foods in salad bars or for sale in markets, with the above exceptions
U.S. government regulations require sulphites in excess of 10 ppm in manufactured foods and beverages, including alcoholic beverages, to be listed on labels
Sulphites are permitted in a wide rage of dried, frozen, and processed foods, sweeteners, and snack foods

44. Sulphite Sensitivity
There is no evidence that avoiding all sources of dietary sulphites improves asthma
Exposure to sulphiting agents poses very little risk for individuals who are not sensitive to sulphites
Sulphites in foods are not denatured by cooking
Sulphites avidly bind to several substances in foods, such as protein, starch, and sugars. They are not removed by washing
Sulphates do not cause the same adverse reactions as sulphites. They are inert in the body and need not be avoided by people who are sensitive to sulphites

45. Benzoate Intolerance Symptoms
Reported to induce:
Urticaria
Angioedema
Asthma
Rhinitis
Purpura (allergic vasculitis)
Hyperactivity in children
May lead to increase in histamine

46. Benzoates and Parabens: Use in Foods
One of the most commonly used food additives worldwide
Benzoic acid and sodium benzoate (benzoates) are used as antibacterial and antimycotic agents in foods and beverages
Benzoates are most effective as preserving agents at an acidic pH
Benzoyl peroxide is used as a bleaching agent, especially in white flour, white bread, and some white Italian cheeses

47. Benzoates Naturally occurring
Benzoates occur widely in nature as simple salts (sodium, potassium), esters, and amides
Natural benzoates are present at the highest levels in:
Cinnamon, Clove, Anise, Nutmeg
Prunes
Black Tea
Berries
Especially Raspberry and Cranberry

48. Monosodium Glutamate (MSG)
Flavouring common in Chinese cooking and increasingly used to flavour Western foods
Sensitive individuals report a variety of symptoms that are usually classified as “Chinese Restaurant Syndrome” (also known as Kwok’s syndrome)

49. Most Frequently Reported Symptoms of Sensitivity to Monosodium Glutamate
Headache, back of head and neck
Numbness of face
Tingling/burning of face and chest
Tightness in chest
Rapid heartbeat
Nausea, diarrhea, stomach ache
Weakness, balance problems
Confusion
Blurred vision
Chills, shakes, perspiration
Difficulty breathing
Asthma in asthmatics

50. MSG Sensitivity
Experts are widely divided on the subject of MSG sensitivity
One review “led to the conclusion that ‘Chinese Restaurant Syndrome’ is an anecdote applied to a variety of postprandial illnesses”
Some clinicians have estimated that the prevalence of “Chinese Restaurant Syndrome” may be as high 1.8% of the adult population

51. Characteristics of MSG Sensitivity
Alcohol may increase the rate of absorption of MSG and increase the severity and rate of onset of symptoms
Symptoms usually occur about 30 minutes after eating a meal high in MSG
Asthma occurs 1 to 2 hours after MSG ingestion, and even as long as 12 hours later
Vitamin B6 (pyridoxine) deficiency may be a factor in some MSG sensitive people

52. Sources of MSG Present in many flavouring mixtures: Accent Zest
Gourmet powder Glutavene
Glutacyl Chinese seasoning
Subu Vetsin
Ajinomoto Kombu extract
Mei-jing Wei-jing
RL-50
Hydrolysed vegetable protein (HVP)
Hydrolysed plant protein (HPP)
“Natural flavour” (may be HVP)

53. Sources of MSG
Used as a flavouring in foods, especially in Chinese cooking, in canned foods (e.g. soups), and restaurant meals
Some sensitive individuals will also react to monopotassium glutamate
Several foods, such as tomato, mushrooms, and cheese contain natural glutamates

54. Nitrate and Nitrite Sensitivity
Nitrates and nitrites are used in foods as preservatives
Particularly protective against Clostridium botulinum
Impart flavour and preserve colour in manufactured foods, especially meats
Symptoms
Reports of headache in sensitive individuals

55. Nitrates and Nitrites in Foods
Labels list sodium nitrate, potassium nitrate, sodium nitrite, and potassium nitrite in manufactured foods
Present at high levels in processed meats:
• Pepperoni • Frankfurters
• Hot Dog Wieners • Salami
• Bologna • Other Luncheon Meats
• Bacon • Ham
• Smoked Fish • Some Imported Cheeses

56. Nitrates in Plant Foods
Nitrates occur naturally in plants: the major source is nitrate-containing fertilizers
Some species of plants tend to accumulate nitrates more than others:
• Spinach • Celery
• Beets • Lettuce
• Radishes • Collards
• Turnip Greens • Eggplant

57. Summary Food allergy is most prevalent in babies and children
Food intolerances predominate in adults
Infant onset food allergy is mostly due to Class 1 allergens
Sensitization is by ingestion of allergen
Adult onset food allergy mostly due to Class 2 allergens
Sensitization by allergen inhalation or contact
Food allergy: must avoid all sources of the allergen
Food intolerance: dose related
Several additional factors sometimes required to elicit symptoms
Food intolerance can exacerbate food allergy