Subsections
According to the European Federation of Allergy and Airways Diseases Patients
Association an estimated 4 per cent of adults and 8 percent of children in the
European Union suffer from food Allergies.
First signs of an allergic reaction to food:
- Running nose
- Itchy skin rash
- Tingling in the tongue, lips, or throat
- Swelling in the throat or other parts of the body
- Abdominal pain
- Eczema
- Dizziness
- Diarrhoea or vomiting
- Wheezing
Major serious food allergens: Cereals containing gluten (i.e. wheat, rye, barley, oats, spelt or
their hybridised strains, and products thereof), fish, crustaceans, egg
(globulin; albumin; Apovitellenin; livetin; ovalbumin; ovomucin; ovomucoid;
ovovitellin; phosvitin), peanut, soybeans ( soy protein, textured vegetable
protein TPV, hydrolysed plant protein, hydrolysed soy protein, hydrolysed
vegetable protein,), milk and dairy products including lactose (milk sugar),
nuts i.g. almond (Amygdalus communis), hazelnut (Corylus avellana),walnut
(Juglans regia), cashew (Anacardium occidentale),pecan nut(Carya illinoiesis),
Brazil nut (Bertholletia excelsa), pistachio nut (Pistacia vera), macadamia
nut, Queensland nut (Macadamia ternifolia), celery and other foods of the
Umbelliferae family, mustard, sesame seed, sulphur dioxide and sulphites (at
concentrations of more than 10 mg/kg or 10 mg/litre expressed as SO
) are
the major serious food allergens.
The most common food allergens are found in a wide variety of processed foods
and may cause allergies or intolerances in consumers endangering their
health.
Food allergens are part of a wide group of adverse reactions to foods.
In order to provide all consumers with better information and to protect the
health of certain consumers all ingredients must now be included in the list of
ingredients.
Labelling: According to labelling
Directive 2000/13, a full list of ingredient was considered not to be
compulsory when the compound ingredient constitutes less than 25% of the
finished product. Many of allergenic ingredients were so hidden.
The Directive 2003/89/EC amended Directive 2000/13. The mandatory inclusion on
food labels of the most common food allergen ingredients and their derivate is
contained in this directive which came into force in 2005.
A similar law goes into effect in the US on 1 January 20 due to the US Food
Allergen and Consumer Protection Act (FALCPA). Food makers have to list in
lain, common language, the presence of any of the eight major food allergens-
milk, egg, peanut, tree nut, fish, shellfish, wheat and soy a product's label.
When cross-over of food allergens is not possible to be completely avoided, the
warning " May contain traces of ..." should be included in the label.
| Foods |
Per cent |
|---|
| Milk (cow) |
42.0 |
| Egg (hen) |
|
| - Egg white |
14.6 |
| - Egg yolk |
9.0 |
| - Egg white and yolk |
9.7 |
| Fish |
11.0 |
| Citrus fruit |
4.5 |
| Legume |
2.5 |
| Horse meat |
1.3 |
| Meat |
1.0 |
| Vegetable |
1.0 |
| Onion |
1.0 |
| Nuts, chocolate and others |
2.0 |
Food allergens and Good Manufacturing Practice:
According to the Institute of Food
Science and Technology (IFST) the "greatest
care must be taken by food manufacturers to formulate foods so as to avoid,
whenever possible, inclusion of unnecessary major allergens as ingredients.
Food makers must organise raw material supplies, production schedules and
cleaning procedures so as to prevent cross-contact of products by "foreign"
allergens.
Training of all personnel should be focused on the understanding of necessary
measures and the reasons for them.
Food manufacturers should comply with the relevant labelling legislation
providing appropriate warning, to potential purchasers, of the presence of a
major allergen in a product.
An appropriate system for recall of any product found to contain a major
allergen not indicated on the label should be in place ".
[1548]
The labelling legislation of the European Community is ruled by two main
directives:
Directive 2003/89 EC [1549]
New labelling rules in European Directive (2003/89/EC) ensure that all
consumers are given comprehensive ingredient listing information and make it
easier for people with food allergies to identify ingredients they need to
avoid.
The new rules came into force on 25 November 2004 establishing a list of 12
food allergens, which have to be indicated by reference to the source allergen
whenever they, or ingredients made from them, are used at any level in
pre-packed foods, including alcoholic drinks. The list consists of cereals
containing gluten, crustaceans, eggs, fish, peanuts, nuts, soybeans, milk,
celery, mustard, sesame, and sulphur dioxide at levels above 10mg/kg or 10
mg/litre expressed as SO
.
The new rules also removed the "25%" rule in the previous legislation, which
meant that individual ingredients making up a compound ingredient did not have
to be listed if the compound ingredient made up less than 25% of the finished
products. So, apart from a few exceptions, all ingredients now have to be
indicated on the label, even when they make up only a small proportion of the
product.
[1550]
Mustard and products thereof are included in the list of the Annex IIIa of the
Directive 2003/89/EC [1549].
Mustard seed from Brassica juncea are ground, tap water is added and the slurry
is incubated at 50°C for 30 minutes. The allyl isothiocyanate is released from
its precursor by the enzyme myrosinase. The oil is obtained by steam
distillation under reduced pressure. The mustard seed oil is separated from
water by centrifugation and dried with sodium sulphate and filtered.
Mustard is known to trigger allergic reactions or intolerances in sensitive
individuals and was therefore included in this list and must be labelled..
International Flavours & Fragrances (IFF) requested the European Commission
exempt mustard seed oil from labelling European Food Safety Authority to
evaluate the scientific data and came to the following conclusion:
IFF claims that mustard seed oil is not likely to trigger adverse reactions on
the basis of two arguments: 1) the typical low levels of mustard seed oil in
foods, and 2) the in vitro demonstration that proteins are not present in
amounts higher than 1.5 microg/g in five samples of mustard seed oil analysed
with an ELISA test developed by the applicant.
According to the Panel IFF did not take into account the known toxicity of
allyl isothiocyanate and its role in causing allergic contact dermatitis, or
the possibility that proteins not detectable with the ELISA test could cause an
IgE-mediated reaction (Lerbaek et al., 2004; Kohl and Frosch, 1990).
The main volatile component of mustard seed oil is allyl isothiocyanate
(97-100%). which has been classified as toxic by inhalation, in contact with
the skin and if swallowed, and irritating to eyes, respiratory system and skin
Allergic reactions to mustard, including severe anaphylactic reactions, are
well documented in clinical and laboratory studies. Mustard allergy may
account for 1-7% of all food allergies with regional variations.
Mustard allergens are resistant to heat and to enzymatic degradation, and
therefore are not markedly affected by food processing. The major mustard
allergens identified are Sin a 1, belonging to the 2S albumin family, and Bra j
1, also from the 2S albumin family, with a MW.
A new major allergen in mustard seeds has been recently isolated and
identified, an 11S globulin called Sin a 2 with a MW of 51 kDa (Palomares et
al., 2005), but not all mustard allergens and their occurrence in different
species are known. [1551] [1552]
In addition, allyl isothiocyanate is a major skin-sensitizing agent (non
IgE-mediated mechanism). Mustard protein allergic individuals may react to the
protein content of the oil. Individuals sensitised to the skin-sensitising
component allyl isothiocyanate may react to oil even in the absence of mustard
proteins (Lerbaek, 2004).
Taking account of the potential allergen content and well documented clinical
allergic reactions in individuals sensitive to mustard (NDA, 2004a), it is
appropriate for the Panel to assess the likelihood that mustard seed oil may
cause an allergic reaction in mustard-allergic individuals.
Mustard seed oil (allyl isothiocyanate) will therefore not be exempted from
labelling as allergen.
Directive 2005/26 EC [1553]
Some ingredients derived from the listed allergenic foods are so highly
processed that they are no longer capable of triggering an adverse reaction. A
list of products that are temporarily exempt (til 25 November 2007) from the
labelling requirements of 2003/89/EC was published as Commission Directive
2005/26/EC
May contain...warning [1548]
Manufacturers often use phrases such as "may contain nut traces" to show that there could be traces of nut in a food product, either in the ingredients, or because it has entered the product accidentally during the production process. It is not a legal requirement to say on the label that a food might contain traces of nut, but many manufacturers label their products in this way. Some members of the public have expressed concern that "may contain" labelling is used too much and could undermine valid warnings on products and restrict people's choice unnecessarily.
EuroPrevall:
EuroPrevall is an EU-funded multidisciplinary project aiming to improve
quality of life for food allergenic people.
The partner organisations of the project will:
1- Characterise the pattern and prevalence of food allergies across Europe in
infants, children and adults.
2- Develop methods to improve the quality of food allergic diagnosis, reducing
the need for food challenge tests.
3- Determin the impact of food allergies on the quality of life and its
economic cost for food allergic people and their families, workplace and
employers, and healthcare.
Document No. 00P-1322 International Dairy Foods Association:
International Dairy Foods Association IDFA
helped develop new guidelines for clear labeling of allergenic
ingredients on food labels and supports the implementation of these guidelines,
encourages disclousure of allergenic ingredients in clear and simple language,
and is dedicated to assisting dairy processors in preventing cross
contamination. [1817]
IDFA urges all members to review their policies and verify that they are
operating within the new allergen guidelines. Further it ist being recommended
that member companies follow these recommendations:
1- Review formulations to identify the presence, if any, of the 8 major
allergens.
2- Contact ingredient suppliers to determine if ingredients they supply
contain any allergen, including components of flavours, colors, incidental
additives and processing aides, which may not be required to list specific
ingredients.
3- Review their current labels to ensure that if any allergen are present they
are included in the ingredient declaration in terms that are easily understood
by consumers. The dairy industry is currently using the following labeling
guidelines, which are among the options listed in the Allergy Labeling
Guidelines issued by the Allergen Issues Alliance.
- Use of parenthetical statement following the ingredient name or class of
names that identifies the presence of an allergic ingredient. For example,
caseinate (derived from milk); and
- Use of a commonly understood name that identifies the presence of the
allergen such as "natural walnut flavour."
4- Advisory statement should not be used as a substitute for Good
Manufacturing Practices (GMP). Only use advisory label statements such as "may
contain..." when all four of the criteria established in the Allergen
Guidelines are met. These criteria are:
- The presence of a major food allergen is documented throughout visual
examination or analytical testing of the processing line, equipment,
ingredient or product, or other means.
- A major food allergen is present in some, but not all, of the product.
- The presence of a major food allergen is potentially hazardous.
- The risk of presence of a major food allergen is unavoidable even when
current GMP's are followed.
Food allergy diagnosis:Food allergy is
diagnosed by a process of elimination.
The first step is a detailed patient history to establish a pattern of
reactions to foods in order to decide if the facts match with a food allergy.
Other causes such as food intolerance or other health problems, should at this
point be excluded.
The diagnosis is usually based on the symptom and dietary histories and
subsequently confirmed via more specific investigations including skin prick
tests, blood chemistry, and response to dietary restriction.
Test Diets: These are oral food challenge
tests.
Skin prick tests: These tests are performed if history, diet diary or elimination
diet suggests a specific food allergy to be present.
A drop of allergen extract is placed on the skin of the lower arm, and the skin
scratched with a needle. A positive reaction is shown by the rapid development
of a localised reddening and swelling.
The only conclusive demonstration of food allergy (gold standard) is the result
of a double-blind placebo-controlled food challenge, which must be performed in
hospital with resuscitation facilities available because even extremely small
doses can lead to a life-threatening reaction.
The sensitivity of in vitro immunoassays compared with prick/puncture skin
tests has been reported to range from 50-90% with an average of about 70%.
Skin testing, therefore, continues to be the preferred method for the
diagnosis of IgE-mediated sensitivity.
Total serum IgE (Radio-Immuno-Sorbens-Test RIST test) RIST Test evaluates only the total amount of IgE antibody. The RAST
test is much more complicated but gives the answer to what allergen the patient
is sensitive.
Allergen-specific IgE antibody testing (Radioallergosorbent RAST
testing: The allergen-specific IgE antigen testing is done to screen for a type I
hypersensitivity to a specific substance or substances in response to acute or
chronic allergy-like symptoms in patients. The specific serum IgE Testing
incorporates the use of microwell plastic strips, which have been coated with
allergen proteins. Serum or plasma is exposed to the microwell and the bound
IgE antibody is detected using an enzyme labelled anti-human IgE antibody.
Peroxide substrate detects the levels of enzyme present, which is directly
proportional to the level of specific IgE bound to the specific allergen.
Food Sensitivity Panel: The
measure of high levels of IgG, IgA and IgM antibodies in serum for specific
food antigens is a dependable diagnosis of specific forms of food sensitivity.
Testing about 96 different types of food indicates not only gastrointestinal
diseases,but also neuromuscular and cardiovascular events, as well as cross
reactivity of food antigens with tissue antigens as an initiating process in
some autoimmune diseases.
Available are following test by ALLETESS Medical Laboratory of the serum of a patient [1809]:
- IgG/IgA to Gliadin
- IgG/IgA to Gluten
- IgG/IgA to Casein
- IgG/IgA to lactalbumin
- IgG/IgA to Ovalbumin
- IgG/IgA to beta-lactalbumin
- Reticulin Antibodies
- Tissue Transglutaminase (tTG)(Specific to Endomysium) Antibody IgA
Related tests: Complete blood count (CBC), white blood cell
differential count, eosinophil count, basophil count are blood tests for an
indirect indication of an ongoing allergic process with special attention to
the eosinophils and basophils. Elevation of their number suggest an allergy,
but they may also be elevated for other reasons.[1780]
| |
|
|
Skin reaction |
time of |
|---|
| Reaction |
Description |
Antibody |
and cellular infiltrate |
Onset |
|---|
| Type I |
Anaphylaxis |
IgE |
Allergy skin test |
1-20 min |
| |
|
|
eosinophils |
|
| Type II |
Cytotoxic |
IgG/IgM |
- |
- |
| Type III |
Immune |
IgG(IgM) |
Arthus reaction) |
7-10 hrs |
| |
complexes |
|
(PMNs) |
?-10 hrs |
| Type IV |
Delayed-type |
- |
TB skin test |
1-3 days |
| |
hypersensitivity (DTH) |
|
mononuclear cells |
|
Treating the allergic state: At present there is no cure for food
allergy, The only option is to avoid eating the problem food. Food allergic
young people between 16 to 24 years are more likely to experience a severe
allergic reaction leading to death.
The following measures can be taken:
- Avoidance of all allergens if possible
- Desensitisation (induce IgG)
- Drug:
Antihistamines and decongestants
Corticosteroids
Cromolyn sodium
Ephedrine and isoproterenol
Incidence of most common food allergies: A relative small group of foods or food products are responsible for
most cases of food allergies.[1779]
Milk allergies: Two out of a hundred babies under 12 month are
allergic to cow's milk.
It is the most common food allergen in childhood but nine out of ten milk
allergic children are no longer allergic by the age of three.
It is unusual for adults to be milk allergic, but a small number of children
have an anaphylactic reaction to milk and remain allergic into adulthood.
Because the proteins in milk are similar in sheep, goats and cows, people who
are usually allergic to cow's milk are usually allergic to other milks and
dietary calcium must be sourced from non-dairy foods.
Egg allergies: Allergy to eggs also occurs in young children rather than adults.
Most egg allergies disappear with time but whilst allergic to hen's eggs
individuals are also allergic to other eggs.
Shellfish allergies: Shellfish allergies
are unusual in children, but reactions to fish are found in both children and
adults. Severe reactions are more frequently found with these foods, including
anaphylaxis.
Cooking does not destroy the proteins responsible for the allergy, but some
people may be allergic to the cooked food whilst they are able to eat raw
fish.
Those who are allergic to cod are also allergic to hake, carp, pike and
whiting. The protein that causes shellfish allergy are usually found in the
flesh whilst the proteins responsible for allergy in foods such as shrimps are
in the muscle and the shells.
Fruits and vegetable allergies:
Generally they are mild. The proteins causing allergy in fruits and vegetables
are similar to pollen proteins. Four out of ten individuals who are allergic
to tree and weed pollens are also allergic to some fruits, and people who are
allergic to birch pollen are likely to be allergic to apples.
Many of fruit and vegetable proteins are destroyed by cooking. The cooked food
may be safe to eat. However, Kiwi fruit allergy ,
and peach and Rosaceae fruit allergies are severe and
life-threatening. Their proteins are resistant to cooking and are found in
fermented products such as wine and beer.
Peanuts allergies Peanuts are not nuts but
legumes like soya, peas and beans. Peanuts are one of most allergenic foods
and cause severe reactions. This allergy persists throughout life. Traces found
in processed oils or on cooking or serving utensils can be sufficient to
trigger anaphylaxis.
Tree nuts allergies: They are also called
as true nuts and almond, Brazil nut, cashew nut, hazelnut, macadamia, pecan,
pistachio, Queensland and walnut.
Our body has a host of defensive mechanisms to prevent food from making contact
with our immune system. Even so some people have a tendency to react to
particular foods and develop food allergies.
This tendency is present from birth and may be affected by environmental
factors such as childhood infections.
Food tolerance is poorly developed in infancy and children become more
susceptible to developing food allergies than adults. Children who are
introduced to cow's under the age of 6 month are more likely to develop milk
protein allergy. Some babies are sensitised to peanuts, milk and eggs at or
around birth. It is possible that they were exposed to these allergens in the
womb or during breath feeding.[1779]
Peanut, vaccination and atopic allergic disease
revision.
The UK Department of Health advice issued by the Committee on Toxicity in
Chemicals in Food, Consumer Products and the Environment (COT) issued in 1998
a precautionary advice that pregnant or breast-feeding women with a family
history of atopy, may wish to avoid eating peanuts during pregnancy and
lactation as this could increase the chances of peanut sensitisation in
children.
Atopy or atopic syndrome is an allergic hypersensitivity affecting parts of the
body not in direct contact with the allergen. There appears to be a strong
hereditary component linked to genes such as 5q31-33 with a cluster of cytokine
genes. The individual components, such as asthma, eczema or hay fever, are all
caused at least in part by type I I hypersensitivity reactions.[] [1800]
Consumption of peanut during pregnacy: Dr. Tara Dean and Dr. Carina
Venter assessed the compliance with this recommendation and its impact upon
peanut sensitization.
In this study children sensitized to peanuts were found, but their mothers had
not consumed peanuts during pregnacy. The scientists conclude therefore that
maternal consumption of peanuts during pregnancy was not associated with peanut
sensitization in the infant.
The majority of mothers avoided peanut consumption during pregnancy. The
authors found that either the government advice is misunderstood by mothers,
or that those who communicate the advice have not fully explained who it is
targeted at, and stress the necessity of a review of the 1998 COT document.
The authors call for clear, consistent factual advice and information about the
real risks associated with peanut consumption during pregnancy/lactation and
peanut allergy in the developing child, and specifically to whom these risks
apply. [1801]
Atopy and vaccination: Analysing prevalences of allergic
sensitization and atopic disease in relation to vaccination coverage. Grüber
and colleagues (2003) found that children with a higher vaccination coverage
seemed to be transiently better protected against development of atopy in the
first years of life. [1802]
Grüber reassured in 2005 that common childhood vaccines are unlikely to
promote atopic disease. He wrote that possible future development of atopic
symptoms is most likely not causally related to vaccination but a coincidence.
However, according to Grüber, vaccines specifically designed to down-regulate
Th-2 type immunity have to be further elucidated if they are safe and
effective in preventing the development of atopic disease. He concludes that
effective protection against potentially life threatening or disabling
infectious diseases should be offered to every child-atopic or not.
[1803]
According to Nakajima and colleagues in 2007 all few effects, which were seen
in their study concerning vaccination and atopic disease, were small and
age-dependent. The study supports numerous previous studies of no effect of
vaccines on asthma. The authors conclude that the fear of their child
developing atopic disease should not deter parents from immunising their
children, especially when weighed against the benefits. [1804]
Western lifestyle and allergies: Contact with new drugs, cosmetics,
exotic fruits and spices can be one cause of growing number of food allergies
in the industrial countries. Results of studies suggest that a western
lifestyle is associated with allergic diseases in
childhood.[1805]
For 1995-1996, the International Study of Asthma and Allergies in Childhood
(ISAAC) found prevalence of self-reported asthma symptoms in children aged
13-14 years at 2.6 to 4.4 per cent in Albania, Roumania, Georgia, Greece
and Russian Federation. In United Kingdom and Ireland these rates reached 32
percent, suggesting that western lifestyle is associated with allergic diseases
in childhood.
| Land |
Prevalence |
|---|
| UK |
36% |
| Australia |
33% |
| New Zealand |
32% |
| Ireland |
28% |
| USA |
24% |
| South Africa |
16% |
| Japan |
13% |
| China |
 5% |
| Indonesia |
5% |
| India |
5% |
| |
|
|---|
(Source ISAAC Study)
Gut microflora and immune system: Changes in gut microflora caused by
widespread use of antibiotics and today's high fat, lowfibre diet could be
responsible for a major increase in allergies in recent years.
Gary Huffnagle is an associated professor of internal
medicine and of microbiology and immunology at the University of Michigan. He
says that researches indicates that microflora lining the walls of the
gastrointestinal tract are a major underlying factor responsible for the
immune system's ability to ignore inhaled allergens. Changes in the microflora
in the gut upsets the immune system's balance between tolerance and
sesitization.
To test this hypothesis, Balb/C laboratory mice were given a five-day course of
antibiotics, killing their gut bacteria. A single oral introduction of
Candida albicans stimulated an increase of
growth of this yeast in the gut of the mice. This is a common side-effect of
antibiotics.
An increased airway hypersensitivity to ovalbumin (egg whites) inserted via
nasal cavities was noted.
Huffnagle says that differences in host genetics and the type of allergens does
not matter as the response had been identical in all studies. It confirms that
microflora are the key to maintain a balanced immune response. Changing the
composition of microflora in the gut predisposes animals to allergic airway
diseases. Allergic sensitization can also occur outside lungs
[1806].
However, an article by Sunia Foliaki, from the International Study of Asthma
and Allergies in Childhood (ISAAC) published in the International Journal of
Epidemiology in 2004 says that findings are generally not consistent with the
hypothesis that antibiotic use increases the risk of asthma, rhinitis, or
eczema. If there is a casual association of antibiotic use with asthma risk, it
does not appear to explain the international differences in asthma prevalence.
It has been hypothesized that antibiotic use early in life may increase the
subsequent risk of asthma. Foliaki conducted an ecological analysis of the
relationship between antibiotics sales and the prevalence of symptoms of
asthma, allergic rhinoconjunctivitis and atopic eczema in 99 centres from 28
countries[1807].
The findings of Huffnagle gives a new dimension to the relationship between gut
microflora and immunology trying to explain the different occurrence of East
and West asthma.
Allergens: Allergens are macromolecules (usually
proteins) which are involved in sensitising and eliciting allergic reactions.
The International Union of Immunological Societies (IUIS) published in 1986 the
characterisation and nomenclature of allergen which was revised (Official list
of allergens I.U.I.S. Allergen Nomenclature Sub-Committee 2003.03.02)
http://www.allergen.org/Archive/Meetings/2003/List 20030302.pdf and List of
allergens as of September 12, 2005 http://www.allergen.org/list.htm
standardisation allergen preparations guidelines.
Food allergy is a very individual problem. Treatment of food allergy involves
changes in the lifestyle.
Elimination diet: Food allergy is best treated by avoiding the foods
that cause it.
Special diets are the most often used treatment for food allergies. If the
patient is allergic to only one or two foods, elimination of these foods may
be the only treatment.
The best thing is to ban the foods which cause the problem from the kitchen.
Ready to eat meals from the supermarket must be carefully screened to avoid the
offending ingredients. New food labelling directives gives a better chance to
avoid specific allergen.
Rotation diet: Rotation diets are
necessary when a patient has multiple food allergies. The foods causing the
allergy must be eliminated and all other foods should be eaten in intervals of
four to five days. This reduces the exposure to many other foods to which the
person has also unknown subclinical allergies. This will avoid future
intolerance to these foods. The ideal rotation interval can vary from person to
person and from food to food, but should never be less than four days.
No food should be eaten in extremely large quantities. Rice should not make up
half of the food of the day. New and unusual foods should be included in the
diet, to avoid eating one food in large quantities.
Medication: Mild allergies may be
controlled by nonprescription antihistamines. More severe cases need
epinephrine and antihistamine medication and a medical bracelet
Severe cases need an allergy kit that contains everything necessary for an
epinephrine shot. All child caregivers should know how to recognise the signs
of a severe allergic reaction and how to give an epinephrine shot.
Food intolerance:
Food intolerance do
not involve the immune system. It includes reactions to histamines and other
amines found in the foods, and lactose intolerance, where individuals lack the
enzyme necessary to break down lactose in the gut. Such adverse reactions to
food do not involve the immune system and are also called non-allergic food
hypersensitivity reactions. They are also called
pseudoallergy.
Food, additives and drugs are the main responsibilities for pseudoallergies.
Substances which may trigger a pseudoallergy are: Food colours, preservatives
such as benzoic acid and sulfite, acetysalicyl acid and other not steroidal
antiphlogystica.
Salicilates contained in foods may cause pseudoallergies.
Foods high in salicilates are: Berry fruits,
oranges, apricots (Prunus armeniaca), pineapple (Ananas comosus), cucumber
(Cucumis sativa), olives (Olea europaea), grapes and wine. The treatment of
pseudoallergies is similar to that of allergic diseases (antihistamine drugs,
steroids, B2 agonists, epinephrine).
Biogenic amines such as histamine, cadaverine and putrescine can be present in
foodstuffs or be formed during their storage by microbial decarboxylation of
the corresponding amino acids, mainly during fermentation processes. Elevated
concentrations of these compounds also indicate bad hygienic conditions during
the fermentation process.
Foods produced with the help of bacteria have therefore often a high level of
biogenic amines. These foods are yeast extract, some types of cheese,
sauerkraut, red wine and spoiled foods containing meat or certain fishes.
Scombroid poisoning occur when the spiny-finned
fish of the family of Scombridae undergoes improper storage resulting
scombroid toxin. Susceptible fish include albacore, amberjack, anchovy,
Australian salmon, bluefish, bonito, kahawai, herring, mackerel, mahi-mahi,
needlefish, sauri, sardine, skipjack, wahoo and yellowfin tuna. Affected fish
have a metallic or peppery taste.
Biogenic amines are responsible for a pseudoallergy reactions such as headache,
skin irritation or changes in blood pressure.
Milk allergy [1818]
Milk allergy is an immunologically mediated adverse reaction to one or more
milk proteins. In some children the ingestion of milk can trigger the body into
launching an inappropriate immune response to the proteins in milk resulting in
an allergic reaction.
Currently the only treatment for milk allergies is total avoidance of milk
proteins. Initially if the infants are breastfed, the lactating mothers are
given an elimination diet. If symptoms are not relieved or if the infants are
bottle-fed, milk substitute formulas are used to provide the infant with a
complete source of nutrition. Milk substitutes include soy milk, rice milk, and
hypoallergenic formulas based on hydrolysed protein or free amino acids.
Milk allergy is the most common food allergy. It affects somewhere between 2%
and 3% of infants in developed countries, but approximately 85-90% of
children lose clinical reactivity to milk once they surpass 3 years of age.
Lactose intolerance [1819] []
Lactose intolerance is marked by a relative or absolute absence of the enzyme
lactase in the small intestine which prevents metabolism of lactose.
It is a clinical syndrome with symptoms including abdominal pain, diarrhoea,
nausea, flatulence, and/or bloating after ingesting lactose-containing
substances. Lactose is not absorbed in the gut, and can draw fluids into the
intestine by osmosis, which produces diarrhoea, and the carbohydrate can be
metabolised by certain intestinal bacteria that produce carbon dioxide, methane
and hydrogen as waste products, thereby leading to flatulence.
Differences between primary, secondary, congenital, and developmental lactase
deficiency are discussed in a review from the American Academy of Pediatrics
(AAP).
Treatment consists of use of lactase-treated dairy products or oral lactase
supplementation, limitation of lactose-containing foods, or dairy elimination.
The American Academy of Pediatrics supports use of dairy foods as an important
source of calcium for bone mineral health and of other nutrients such as
protein, and riboflavin that facilitate growth in children and adolescents. If
dairy products are eliminated, other dietary sources of calcium or calcium
supplements need to be provided.
According to AAP pediatricians and other pediatric care providers should
maintain awareness of the benefits and controversies related to the consumption
of dietary milk products and milk-based infant formula. A lactose tolerance
test, a hydrogen breath test, or a stool acidity test is required for a
clinical diagnosis.
Most adults in the world are lactose-intolerant: the majority of humans stop
producing significant amounts of lactase sometime between the ages of two and
five. A relatively recent genetic change caused some populations, including
many northern Europeans, to continue producing lactase into adulthood; these
lactose-tolerant populations are in the minority. Lactose intolerance is an
autosomal recessive trait, while lactase-persistence is the dominant allele.
Important lactose intolerant ethnic groups are gathered in the south of
Africa, China and Hispanics ranging from 100 to 65% of cases. Meanwhile in UK,
Germany and other states of northern Europe have only 2% of persons
suffering from intolerance to lactose.
Yoghurts containing live cultures are well tolerated by people with lactose
intolerance because the bacteria partially digest the lactose into glucose and
galactose. Aged cheeses, such as Cheddar and Swiss, have lower lactose contents
than other cheeses.
New lactic acid bacteria and a Streptococcus strain mix reduce milk
allergenicity [1821]
Kleber and her colleagues from the Germany's University of Hohenheim report
that over70% of beta-lg antigenicity content in the sweet whey and 90% in
skim milk were reduced using a wide range of lactic acid bacteria
(Lactobacillus) independently or in mixture 1:1 with Streptococcus
thermophilus subspecies salivarius incubated at 40
C for 24 hrs.
The research is important because 80 per cent of all cases of milk allergies
is caused by the whey protein beta-lactoglobulin (beta-lg)
which is not present in human milk.
Antigenicity refers to the capacity to induce an immune response. In this study
only the antigenity of beta-lg was tested and not the allergenicity. The
enzymes are reported to be more or less specific with some better at reducing
the beta-lg content in milk and/ or whey.
The research has industrial relevance regarding new fermented milk products
with reduced antigenic properties
[1822] []
Lactose intolerance is caused by a shortage of the enzyme lactase, which is
produced by the cells that line the small intestine. Lactase breaks down milk
sugar into two simpler forms of sugar called glucose and galactose, which are
then absorbed into the bloodstream. Lactose intolerance occurs in about 25% of
people in Europe; 50-80% of people of Hispanic origin, people from south
India, black people, and Ashkenazi Jews; and almost 100% of people in Asia and
American Indians.Lactose intolerance is a problem caused by the digestive
system.
Symptoms are often the same of lactose intolerace. Cow's milk is an allergic
reaction triggered by the immune system.
Common symptoms, which range from mild to severe, include nausea,
cramps, bloating, gas, and diarrhea. Symptoms begin about 30 minutes to 2 hours
after eating or drinking foods containing lactose. The severity of symptoms
depends on many factors, including the amount of lactose a person can tolerate
and a person's age, ethnicity, and digestion rate.
There are sophisticated tests for the diagnosis of lactase malabsorption,like
the Lactose Tolerance Test, the Hydrogen Breath Test and the Stool Acidity
Test. However, the diagnosis can be made easily on the basis of clinical
history. Improvement in symptoms after eliminating such foods and worsening
when they are reintroduced confirms the diagnosis.
No treatment can improve the body's ability to produce lactase, but symptoms
can be controlled through diet.
Lactase concentration after birth and declines after weaning. In primary
lactase deficiency lactase concentrations declines at the age of weaning. It is
associated with a recessive inherited trait, different between Europeans and
Africans.
Treatment: In primary lactase deficiency the development of symptoms
depends on how much lactose needs to be ingested before the available lactase
is saturated. Thus, most people with primary lactase deficiency can ingest up
to 240 ml of milk (12 g of lactose) without developing symptoms.
It may help to divide daily milk intake into several small portions and to take
it with other foods. Yoghurt, curds, and cheeses are better tolerated, because
lactose is partially hydrolysed by bacteria during their preparation and
gastric emptying is slower as these products have a thicker consistency. People
with lactose intolerance should be encouraged to gradually increase their
intake of milk- this causes changes in the intestine that permit higher milk
intake.
Milk-cereal mixtures delay the entry of lactose into the intestine, permitting
better absorption. Since these are cheap and easily prepared at home, their use
should be promoted.
It results from injury to the small bowel mucosal brush border secondary to
viral or non-viral intestinal infection, common in developing countries.
Treatment is directed at the underlying cause.
It is characterized by minimal or absent lactase immediately after birth. It is
a rare disorder.
It occurs in premature infants, because lactase levels do not increase until
the third trimester of a woman's pregnancy. The deficiecy, however, rapidly
improves as the intestinal mucosa matures.
For those who react to very small amounts of lactose or have trouble limiting
their intake of foods that contain it, the lactase enzyme is available without
a prescription to help people digest foods that contain lactose. The tablets
are taken with the first bite of dairy food. Lactase enzyme is also available
as a liquid. Adding a few drops of the enzyme makes lactose more digestible for
people with lactose intolerance.
Young children and infants with lactase deficiency should not consume
lactose-containing formulas or foods until they are able to tolerate lactose
digestion. Most older children and adults do not have to avoid lactose
completely, but people differ in the amounts and types of foods they can
handle.
[]
Short periods of lactose intolerance are common after episodes of infective
diarrhoea and may prolong the diarrhoeal illness. a meta-analysis has shown
that most children with acute diarrhoea can safely continue to receive breast
or undiluted animal milk Milk-cereal mixtures given at frequent intervals
(nearly 2 g/kg/day of lactose or 40 ml/kg/day of milk) were well tolerated by
most children with persistent diarrhoea.
Non-responders will benefit from reducing lactose intake below their current
threshold of tolerance, followed by long term steps directed at improving
adaptation of the intestine.
Recent research shows that yogurt with active cultures may be a good source of
calcium for many people with lactose intolerance. Even though yogurt is fairly
high in lactose, the bacterial cultures used to make it produce some of the
lactase enzyme required for proper digestion. [1822]
[1824]
The Institute of Medicine released a report listing the requirements for daily
calcium intake. How much calcium a person needs to maintain good health varies
by age group. Recommendations from the report are shown in the following
table.
| Age group |
Amount of calcium to consume |
|---|
| |
daily, in milligrams (mg) |
| |
|
| 0-6 months |
400 mg |
| 6-12 months |
600 mg |
| 1-5 years |
800 mg |
| 6-10 years |
1,200 mg |
| 11-24 years |
1,200-1,500 mg |
| 19-50 years |
1,000 mg |
| 51-70+ years |
1,500 mg |
In addition, pregnant and nursing women need between 1,200 and 1,500 mg of
calcium daily Calcium sources.
Many non-dairy foods are high in calcium, including dark green vegetables such
as broccoli, or fish with soft, edible bones, such as salmon and sardines.
| Vegetables |
Calcium |
Lactose |
|
Dairy
products |
Calcium |
Lactose |
|---|
| |
mg |
g |
|
|
mg |
g |
| Soymilk, fotified, 1 cup |
200-300 |
0 |
|
Yoghurt,plain,low-fat |
415 |
5 |
| |
|
|
|
1 cup |
|
|
| Sardines,with edible bones, |
270 |
0 |
|
Milk,reduced fat |
295 |
11 |
| 3 oz. |
|
|
|
1 cup |
|
|
| |
|
|
|
|
|
|
| Salmon,canned, with edible |
205 |
0 |
|
Swiss cheese,1 oz. |
270 |
1 |
| bones, 3 oz. |
|
|
|
|
|
|
| |
|
|
|
|
|
|
| Broccoli, raw, 1 cup |
90 |
|
|
Ice cream,1/2 cup |
85 |
6 |
| |
|
|
|
|
|
|
| Orange, 1 medium |
50 |
0 |
|
Cottage cheese |
75 |
2-3 |
| |
|
|
|
1/2 cup |
|
|
| Pinto beans, 1/2 cup |
40 |
0 |
|
|
|
|
| Tuna,canned,3 oz. |
10 |
0 |
|
|
|
|
| Lettuce greens,1/2 cup |
10 |
0 |
|
|
|
|
Yoghurt with active cultures may be a good source of calcium for many people
with lactose intolerance. Even though yoghurt is fairly high in lactose, the
bacterial cultures used to make it produce some of the lactase enzyme required
for proper digestion.
Clearly, many foods can provide the calcium and other nutrients the body needs,
even when intake of milk and dairy products is limited. However, factors other
than calcium and lactose content should be kept in mind when planning a diet.
Some vegetables that are high in calcium (Swiss chard, spinach, and rhubarb,
for example) are not listed in the chart because the body cannot use the
calcium they contain because these foods also contain substances called
oxalates, which stop calcium absorption.
Calcium is absorbed and used only when there is enough vitamin D in the body. A
balanced diet should provide an adequate supply of vitamin D from sources such
as eggs and liver. Sunlight also helps the body naturally absorb vitamin D, and
with enough exposure to the sun, food sources may not be necessary.
Although milk and foods made from milk are the only
natural sources of lactose, it is often added to prepared foods. People with
very low tolerance for lactose should know about the many food products that
may contain even small amounts of lactose, such as:
Bread and other baked goods, processed breakfast cereals, instant potatoes,
soups, and breakfast drinks, margarine, lunch meats (other than kosher), salad
dressings, candies and other snacks, mixes for pancakes, biscuits, and cookies,
powdered meal-replacement supplements.
Some products labeled non-dairy, such as powdered coffee creamer and whipped
toppings, may actually include ingredients that are derived from milk and
therefore contain lactose such as whey, curds, milk by-products, dry milk
solids, and non-fat dry milk powder. They contain lactose.
About 5 per cent of the general population have some type of food allergy. Some
bowl disorders seem to trigger food hypersensitivity. In case of Irritable
Bowel Syndrome 65 percent of patients may be affected by food allergy.
IBS Irritable Bowel Syndrome:
Irritable bowel syndrome is the most common functional disorder of the
gastrointestinal tract, characterised by abdominal pain, bloating and
irregular bowel function with constipation or diarrhoea. IBS is believed to
affect more than 58 million people wordwide, and more women suffer from it than
men. It is untreatable and intervention involves management of symptoms. It is
not life threatening but it is a long-term condition that involves abdominal
discomfort.
IBS patients had higher IgG4 titers to wheat (PiÜ 0.001), beef (0.001),
pork (0.001), and lamb(P=0.009), and soy beans (P=0.012) as compared with
healthy controls.
The IgG4 titers to potatoes, rice, fish, chicken, yeast, tomato or shrimp were
not significantly different to titers found in healthy people.
Probiotic bacteria has been widely researched for its impact on gut health but
few strains have enough evidence to claim a benefit on IBS symptoms showing
promise in normalising bowel movements. The probiotic bacteria Lp299v
(Lactobacillus plantarum 299v) is the
first probiotic targeting IBS symptoms. It helps to reduce intestinal
discomfort and other symptoms.
International regulations mean that probiotic products cannot carry explicit
disease prevention or treatment claims. Probiotics are, however, marketed with
"friendly" or "good" bacteria that can redress the balance of flora in the gut
and help the user to feel "better" , other address the improvement of the
immune system.[1826]
Probiotics and allergy
Lactobacillus reuteri ATCC 55730 is a probiotic (health-promoting) lactic acid
bacterium widely used as a dietary supplement to improve gastrointestinal,
immune and oral health.
Dietary supplementation with the probiotic L. reuteri ATCC 55730 induces
significant colonization of the stomach, duodenum, and ileum of healthy humans,
and this is associated with significant alterations of the immune response in
the gastrointestinal mucosa. [1827] [1828]
Probiotic bacteria taken by mothers may reduce the likelihood of eczema, also
an allergic disease. Children who were exposed to probiotics around the time of
birth were 40 per cent less likely to develop atopic eczema at four years of
age than children in a placebo group.
However exposure to probiotics did not have any protective effect over asthma
in this study.
Child care infants fed a formula supplemented with L reuteri or B lactis had
fewer and shorter episodes of diarrhea, with no effect on respiratory
illnesses. These effects were more prominent with L reuteri, which was also the
only supplement to improve additional morbidity parameters. [1829]
Dr Steve Allen is investigating the impact of probiotics on allergies giving
Lactobcillus reuteri supplements to mothers for four weeks prior to birth of
their babies and these babies are now being given probiotics for their first
year.
Analysis of breast milk taken from the mothers a couple of days after giving
birth showed increased levels of the anti-inflammatory cytokine (cell signal
substance) IL-10 and reduced levels of TGF-beta-2. The cytokine IL-10 is
central to regulation of the immune system and has anti-inflammatory
properties. However the origine of TGF-B2 in breast milk is uncertain because
it is produced by many cell types and there is the possibility of an
association with a subclinical mastitis. [1830]
Milk kefir and soymilk kefir may help to prevent food
allergies [1831]
Je-Ruei Liu and colleagues evaluated the effect of oral consumption of milk
kefir and soymilk kefir on in vivo IgE and IgG1 production induced by ovalbumin
(OVA) in mice. They found that both foods suppressed the IgE and IgG1 responses
and altered the intestinal microflora. The intestinal populations of
Bifidobacterium spp. and Lactobacillus spp. were increased and Clostridium
spp., decreased. Disorder of the intestinal microflora is told to be closely
related to food allergy development,
According to the authors, milk kefir and soymilk kefir may, therefore, help to
prevente food allergy and enhancement of mucosal resistance to gastrointestinal
pathogen infection.
Soybean lecithin and allergy
The protein fraction of soybeans are allergenic. The vast majority of this
protein is removed in the soy lecithine manufacturing process. The remaining
trace levels of soy proteins in lecithine are not suficient to produce allergic
reactions in the majority of soy-allergic persons. Some of the more sensitive
persons, however should avoid soy-lecithine when used as ingredient in
food.Source labelling of soy-lecithine is provided in the Food Allergen
Labeling and Consumer Protection Act of 2004.
Dr. Hefle and Dr. Taylor from the University of Nebraska advocate that no
conceivable allergenic risk would occur from the use of shared equipment for
products that contain soybean lecithin and products that do not. The transfered
amount of soy protein will be verylow. An "allergen-cleanout" is according to
these authors not necessary. [1832]
The biochemistry of allergies: The
immune system produces immunoglobulins which act as
defence against viral, microbial and fungal infections.
One particular for of
immunoglobulins are immunoglobulin E (IgE) which respond to parasitic
infections such as malaria agents. Some of this group of immunoglobulins are a
response to contact with pollen, dust and food causing allergic reactions such
as hay fever.
The normal function of the body produces IgG and IgA in response to food
proteins. The immune reaction of certain predisposed individuals result in
the so-called Th2 response which leads to the secretion of IgE
immunoglobulins.
This response happens normally only in case of parasitic
infectins such as malaria but also happens in case of hypersensitivity to
food allergens. This is called Th2 response.
Allergies develop in two stages:
Stage 1 - Sensitisation: Sensitisation occurs when an antigen comes
in contact with cells called progenitor B-lymphocytes. These cells break down
the antigen in peptide fragments which are bound in special molecules called
hystocompatibility complex class II complex. This complex is transported to the
surface of the B-lymphocyte cell. The T-cell receptors of CD4 of another cell
type, called T helper cell recognises the foreign peptide on the surface of
the B-lymphocytes, triggering the secretion of specific antibodies, the IgE
immunoglobulins.
Stage 2 - Elicitation: During the elicitation of an allergic reaction,
the IgE becomes associated with specific IgE receptors on the surface of
basophile or mast cells. These cells are packed full of inflammatory mediators
such as histamine.
The cell-bound IgE is crosslinked by the agent in case of a re-exposure. The
mast cell is then caused to release the inflammatory mediators which trigger
the allergic symptoms usually within minutes following exposure, resulting
in asthma, vomiting, eczema and hives (nettle rash).
| Food |
Allergen |
|---|
| Milk |
Casein, beta-lactoglobulin, alfa-lactalbumin |
| Eggs |
Ovomucoid, ovalbumin |
| Fish |
Parvalbumin |
| Shell-fish and |
Tropomyosin |
| Seafood |
|
| Peanut |
7S seedstorage globulin, 11S seed storage globulins, 2S albumin |
| Soya |
7S seedstorage globulin, 11S seed storage globulins, |
| |
Bet v 1 homologue, inactive papain-related thiol protease |
| Tree nuts |
2S albumin, 7S storage globulins, 11S seed storage globulins |
| |
Non specific lipid transfer proteins, Bet v 1 homologue |
| Mustard, Sesame |
2S albumin |
| seeds |
|
| Cereals wheat |
Seed storage prolamins, alfa-amylase, trypsin inhibitors, |
| |
Glycosylated peroxidase |
| Fresh fruit and vegetables |
Homologues of the major birch pollen
allergen Bet v1 |
| Kiwi, peach,celery |
Cysteineprotease, LTP |
| |
|
|---|
Food manufacturers must comply with directives calling for mandatory
declaration of major allergens on labels. Special kits for the detection of
some of these allergens are being developed to help food manufacturers to
screen their raw ware and their production lines for unforeseen cross-over of
traces of ingredients.
Many kits on the market only detect egg white and do not indicate the presence
of egg yolk. Biotrace Tecra Egg Via Kit detects both. Other kits avilable using
simple extraction methods and sensitive specific immunoassay techniques and "
on-site" tests highly effective in the food industry as part of a HACCP
programme: [1808]
- Wheat gluten
- Milk proteins (caseins/caseinates; whey protein and albumin; lactoglobulin)
- Peanut and sesame tests are directed towards their major components. The
antibodies are specific and can be used in a wide rage of food matrices,
including chocolate-based foods, which can sometimes cause problems.
- Soya protein
- Sesame protein
- Tree nuts
ELISA Systems Kits to Detect Food Allergens: The following rapid Elisa (enzyme-linked
immunosorbent assay) kits are available:[1810]
- Almond (Prunus dulcis): It belongs to the tree nuts group. Almonds are a
common cause to food allergy.
- Beta-lactalbumin and casein: Non-dairy products should be tested to ensure
raw and finished products have not been contaminated with milk proteins.
Either beta-lactalbumin or casein can be tested.
- Crustacean: Trompomyosin is a major protein in Crustaceans. It is the major
shrimp allergen and presents evidences of cross-reactivity among crustaceans
and molluscs.
- Egg: It tests only egg white.
- Hazelnut (Corylus avelana): Detects heat stable protein component of
hazelnut.
- Peanut: The proteins Ara h1 and Ara h2 of peanuts are focused. Ara h2 is
heat stable
- Sesame (Sesamum indicum): Allergy to sesame seeds is increasing. In Israel
sesame is a major cause of food allergy. Anaphylaxis has been reported after
ingestion of meat and sesame seed oil.
- Soy: The incidence of allergy to soybean proteins is quite low in comparison
to other major food proteins. However, the increasing consumption of soybean
products makes this test necessary.
Allergies and cross-reactivity
Milk allergy: There are at least 30 antigenic
proteins in milk. Casein is the most commonly used milk protein in the food
industry; lactalbumin, lactoglobulin, bovine albumin, and gama globulin are
other protein groups within the milk.
Digested fractions of milk proteins may induce the production of IgE, IgA, and
IgG antibodies and may trigger complex, variable immune responses. Skin tests
with whole milk proteins are, therefore, misleading because secondary antigens
of digested proteins are not detected.
Accurate diagnosis is important in case of an immediate symptomatic
hypersensitivity to cow's milk protein because a milk-free diet with substitute
formula should be established.
Many children who are allergic to cow's milk protein also show sensitivity to
soy- based products. There are infant formulas in which the milk and soy
proteins are degraded so the immune system does not recognise the allergen and
the product can be consumed safely.
alfa-lactalbumin:
alfa-lactalbumin and beta-lactalbumin are the major cow's milk allergens. The
presence of cow's milk is widespread due also to its unlabelled inclusion as an
ingredient, or to errors in cooking, processing and preparation, especially in
restaurants. For this reason, individuals with milk allergies should avoid
processed foods as much as they can and try to consume foods prepared at home;
only food items with all the ingredients listed on the label should be
consumed.
Hot dog, salad mayonnaise, dressings, and meat products are often produced
using caseinates as emulsifier. Caseinates replaces egg yolk in these products
which resist deep freezing. The same products produced with egg yolk are
extremely sensitive to freezing.
A hot dog may contain caseinate.
Kiwi fruits allergies
Birch pollen and Kiwi allergy: Fruit allergy is
frequently associated with birch pollen.
Kiwi allergy is a new manifestation of birch pollen-associated food allergy
and is mediated by cross-reacting antigens in the kiwi fruit. Kiwi allergy can
be expected in patients with birch pollen allergy exhibiting high levels of
IgE to birch pollen. [1815]
Fahlbusch and associated scientists at the Institute of Clinical Immunology,
at the University of Jena, Germany found that the major allergen for kiwi
allergy is the 30 kDa protein and additionally that the cross-rection between
kiwi and birch pollen allergy is mainly due to carbohydrate moieties.
[1833]
Birch pollen associated Allergies: Basophil activation is associated
with the expression of CD63. In birch-pollen-associated food allergy to celery,
carrot and apple, Bet v 1, Api g 1, Dau c 1 and Mal d 1 are major allergens.
Basophil Activation Test (BAT) and birch pollen associated allergies:
Recombinant allergens have not yet been used in the CD63-based basophil
activation test (BAT). However, the BAT using recombinant allergens provides a
valuable new in vitro method for the detection of sensitization to foods.
In the presented study Erdmann determined specific IgE by the CAP method and
basophil activation by flowcytometry upon double staining with
anti-IgE/anti-CD63 monoclonal antibodies after incubating with purified
recombinant Bet v 1, Bet v 2, Api g 1, Dau c 1 and Mal d.
According to Erdmann double-blind placebo-controlled food challenges remain the
gold standard to confirm food allergy, however, the CD63-based BAT with
recombinant allergens may supplement routine tests for allergy
diagnosis.[1836]
The basophil activation test (using either CD203c or CD63 as activation marker)
has become a robust and reliable test for in vitro investigations of immediate
allergy, complementary to other existing in vitro tests. Inter-laboratory
standardization in clinical decision-making is necessary. Each allergen has to
be assessed one by one to determine its optimal concentration as well as the
definition of the threshold for positivity (using ROC analysis).[1837]
Green and yellow cultivars of Kiwi and allergy The green-fleshed kiwi
Actinidia deliciosa cv Hayward and the yellow-fleshed cultivar
Actinidia chinensis cv Hort 16A are grown commercially. According to
findings of Bublin and associated scientists of the Department of
Pathophysiology, Medical University of Vienna, Austria. the IgE immunoblotting
showed marked differences in the allergen compositions of green and gold
kiwifruit extracts.
Phytocystatin which is a novel plant food allergen, and a
thaumatin-like protein were allergens common for both cultivars. In the extract
of gold kiwifruits two allergens with homologies to chitinases were found.
Actinid was detected exclusively in green kiwifruits.
Green and gold kiwifruit extracts were shown to be highly cross-reactive as
determined by the authors using IgE ELISA inhibition.
The authors conclude that the gold kiwifruit should be considered as new
allergen source for patients allergic to green kiwifruits because of the
presence of common allergens and the IgE cross-reactivity to green
kiwifruit.[1816]
Fescue meadow pollen and kiwi: Fescue meadow pollen cross-sensitise to
kiwi fruits. This was found by Gavrovic-Jankulovic
and associated scientists at the Department of Biochemistry from the University
of Belgrade using the sera from polysensitized patients with specific IgE to
grass pollen and kiwi fruit. According to their findings a 24 kDa kiwi
glycoprotein represent potential major allergen, which share common epitopes
with Fes p 4 and 36kDa meadow fescue allergen. [1811]
Rye, timothy and mugwort pollen and kiwi allergy: The cross-reactivity to
birch, rye, timothy, and mugwort pollen (Artemisia vulgaris) with kiwi was
studied by Rudescko and associated scientists at the the Institute of Clinical
Immunology, at the University of Jena, Germany.
They found that an extract of kiwi was able to bind immunoglobulin E from
kiwi-allergic patients in the immunoblots and EIA. Immunoblots results
revealed a broad spectrum of IgE specificities; 12 allergens were identified
within a range of 15 to 94 kDa, 10 of which cross-reacted with birch,
timothy, rye, and mugwort pollen, while two (25 and 30 kDa) were not inhibited
homologously by pollen. EIA additionally revealed kiwi-specific allergens.
Three proteins of the kiwi extract (25, 30, and 43 kDa) were considered to
contain a carbohydrate miety.
Profilin seems to be relevant in cross-reactivity of kiwi
allergens. [1814]
[1813]
People who are allergic to birch pollen react also to peanuts, hazelnuts,
apples, strawberries, carrots, celery and pulses. Certain proteins in these
foods are so similar in structure to the protein in birch pollen that triggers
the allergy that the body manifests such cross allergy. According to Professor
Dr. Dr. Andreas Hensel, President of the Federal Institute for Risk Assessment
(BfR).BfR stresses that such cross allergy with soy products are possible.
The trigger of the cross allergy to soy is a protein (the PR-10 stress protein
Gly m 4), which is found in soybeans and is similar in structure to the birch
pollen allergen Bet v 1.
The activity of the soy protein Gly m 4 can be dampened through heating to high
temperatures or the protein itself can be destroyed. Allergy sufferers can,
therefore, eat most products with soy ingredients which were heated during
processing without suffering any health disorders.
BfR does not believe that it makes sense for the packaging of soy products to
carry additional warnings for allergy sufferers. Not all soy products contain
the protein Gly m4 that triggers the allergy. At the present time, no official
detection method is available. Furthermore, besides soy numerous other foods
such as peanuts could trigger severe cross allergy in people with a birch
pollen allergy. They include apples, hazelnuts, and celery. Warnings on soy
products would not, therefore, protect people who are allergic to birch pollen
from a cross allergy.
| Food |
Allergen |
IUIS |
Chemical Structure |
|---|
| |
|
Nomeclature |
|
| Milk |
beta-lactoglobulin |
|
|
| |
alfa-lactalbumin |
|
|
| |
Caseine |
|
|
| |
Serum albumin |
|
|
| |
Immunoglobulins |
|
|
| Chicken egg |
ovomucoid |
Gal d 1 |
Glycoprotein |
| |
Ovalbumin |
Gal d 2 |
Glycoprotein |
| |
Conalbumin |
Gal d 3 |
Glycoprotein |
| |
Lysozyme |
|
|
| |
Ovomucin |
|
Glycoprotein |
| |
Apovitellenin I |
|
|
| |
Apovitellenin IV |
|
|
| |
Livetin |
|
|
| |
Alfa-livetin |
|
Serum albumin |
| |
Beta-livetin |
|
|
| |
Gama-livetin |
|
|
| |
Phosvitin |
|
Glycophosphoprotein |
| Cod |
Allergen M |
Gad C 1 |
Glycoprotein |
| Common shrimp |
Antigen-I |
|
Glycoprotein |
| |
Antigen-II |
|
Glycoprotein |
| |
Sa-I |
|
|
| |
Sa-II |
Pen i-1 |
Trompomyosin |
| |
Sa-III |
|
tRNA |
| |
|
Pen a 1 |
Trompomyosin |
| |
|
Pen s 1 |
Trompomyosin |
| |
|
Met A 1 |
Trompomyosin |
| |
|
Par f 1 |
Trompomyosin |
| Peanuts |
Arachin |
|
Glycoprotein |
| |
Conarachin |
|
Glycoprotein |
| |
|
Ara h 1 |
Glycoprotein |
| |
|
Ara h 2 |
|
| |
Aglutinin |
|
|
| |
Peanut 1 |
|
Glycoprotein |
| |
Concanavalin-A-reactive |
|
Glycoprotein |
| |
glycoprotein |
|
|
| |
wheat germ-lectin-reactive |
|
Glycoprotein |
| |
material |
|
|
| Soybean |
Glycinin |
|
Protein |
| |
Beta-conglycinin |
|
Glycoprotein |
| |
2S-Globulin |
|
|
| |
Kunitz Soybean |
|
|
| |
Trypsin inhibitor |
|
|
| Wheat |
|
Tri v BD 47 |
Protein |
| |
|
Tri v BD 17 |
Protein |
| |
|
Tri v BD 15 |
Protein |
| |
0.28 alfa-amylase- inhibitor |
|
|
| |
Alfa-amylase-inhibitor |
|
Protein |
| |
WTAI-CM 16 |
|
|
| Barley |
Alfa-amylase (BMAI-1) |
|
|
| |
BTAI-CMb |
|
|
| Rice |
RP16KD |
|
|
| Tomato |
Profilin |
|
|
| |
Polygalacturonase 2A (PG2A) |
|
|
| |
Beta-fructofuranosidase |
|
|
| |
Superoxide dismutase (SOD) |
|
|
| |
pectinesterase (PE) |
|
|
| Avocado |
Prs a 1 |
|
Hevein-like domain |
| |
|
|
peptides |
| Mustard |
Sin a 1 |
|
2s-albumin |
| |
Bra j IE |
|
2s albumin |
| Kiwi |
24kDa kiwi glycoprotein |
|
Glycoprotein |
| |
43-kDa |
|
|
| |
Actinidin Act c 1 |
|
|
| Strawberry |
20/18-kDa |
|
homologues to Bet v 1 |
| Banana |
Class I chitinases |
|
|
| |
with hevein-like domain |
|
|
| |
33kDa |
|
|
| |
37 kDa |
|
|
| Appel |
Skin-allergen Mal d 1 |
|
Protein similar to |
| |
|
|
Bet v I (birch) |
| Food |
Allergen |
IUIS |
Chemical
Structure |
|---|
| |
|
Nomeclature |
|
A potentially allergenic protein in transgenic Starlink maize [428]
Starlink maize was developed inserting the Cry9C-gene turning it resistant to
plague insects. Starlink had been approved for use in feed and industrial uses,
not for human consumption due to Cry9-protein potential's to cause allergic
reactions. In September 2000 taco-shells in retail-stores contained meal from
StarLink corn were found, triggering a recall. Aventis had to buy back all
harvested Starlink maize as well as Starlink sowing seed.
In July 2001 EPA expert panel concluded that Starlink maize could result in
allergy and decided that it should not be used for human consumption
(www.epa.gov/scipoly/sap/). As contamination of maize for food purposes with
fodder maize can not be avoided, cultivation of Starlink was no longer allowed.
Although traces of Starlink can still be expected in the food chain, it has
never been detected in products on EU-markets.
Commercial enzymes of no concern with regard to food allergy
[429]
Carsten Bindslev-Jensen and colleagues studied the possible allergenicity of a
wide variety of enzyme classes and origins, including enzymes produced by
genetically modified organisms using prick test, histamine release and oral
challenges.
Some positive skin prick test result or a positive histamine release were not
supported by oral challenges using exaggerated dosages of the enzymes, and the
findings were seen without clinical relevance.
No allergenic findings of clinical relevance were related and the authors
concluded that ingestion of food enzymes in general is not considered to be a
concern with regard to food allergy.
Lactococcus lactis IL-10-secreting strain reduces anaphylaxis and allergy responses
[2137] [2138]
Christophe Frossard and Philippe Eigenmann from the University Hospital of
Geneva in a study published in March 2007 found that Lactococcus lactis,
bioengineered to deliver murine IL-10, can decrease food-induced anaphylaxis.
According to the authors, this may provide an option to prevent IgE-type
sensitization to common food allergens. The anti-inflammatory interleukin-10
(IL-10) is a potential regulator for food tolerance.
The researchers administered the transfected Lactococcus lactis to mice and
induced oral sensitization with β-lactoglobulin in the presence of cholera
toxin. Anaphylaxis and blood levels of antigen-specific immunoglobulin E (IgE)
were found to be significantly reduced in mice which had received the L.
lactis strain
Premature and low birth weight babies may develop less allergies in later life when they are exposed to allergens early.
[430]
Liem and colleagues (2007) in a Canadian study, found that immaturity of the
gastrointestinal tract or immune response of prematurity and low birth weight
does not change the risk for development of IgE-mediated food allergies allergy
in childhood.
The researchers disagree with previous studies indicating that at an age less
than 3 years the immature gastrointestinal tracts result in an increased uptake
of food antigens, increasing the risk for sensitization but in this study they
found that food allergy was associated with a maternal history of asthma and
food allergy.
The authors write that a development of immunologic tolerance of the immature
immune system to orally ingested allergens may take place, preventing
sensitivation.
They call for more studies to find out how early exposure to food antigens,
such as pre- and probiotics traces of peanuts, may protect premature children
by increasing immune tolerance to those antigens.
[2139] [2140]
The PARSIFAL study - Prevention of Allergy Risk factors for Sensitisation in
Children related to Farming and Anthroposophic Lifestyle
-looked at farm children from rural
and suburban communities in Austria, Germany, the Netherlands, Sweden and
Switzerland.
Waser and colleagues report that consumption of farm milk, whether boiled or
not, was associated with a reduction in the occurrence of asthma by 26%, hay
fever by 33%, and food allergy by 58%. No effect was observed for eczema.
Other farm-produced products were not related to any allergy-related health
outcome.
It is not know what components of the raw milk may be responsible for such
effects, but it could be linked to the pathogenic and non-pathogenic microbe
levels in the milk, a kind of action observed with probiotic bacteria which
may reduce the risk of certain allergies.
The authors, however, warn that raw milk may contain pathogens such as
salmonella or enterohaemorrhagic E coli and they do not recommend to drink
unheated milk. The authors call for more studies on the omega-3 fatty acids
profile in addition to the microbial content of the farm milk.
[2141]
[2142]
Soy is a common dietary constituent and allergic reactions to soy proteins are
well described. Soy allergy prevalence studies are lacking, estimated
prevalences are about 0.5% in the general population with about 3-6% of
allergic children being allergic to soy proteins. Clinical reactions are
similar to those observed with other major food allergens, such as milk, egg or
peanut and include systemic anaphylaxis.
The ADM and Cargill asked for an exemption of allergy warning for natural
mixed tocopherols (vitamin E, E306) and a range of D-alpha tocopherols acetate
and succinate derived from vegetable oil (soybean oil). Natural mixed
tocopherols are mainly used as antioxidants in fatty foods at a concentration
of about 50 mg/kg (referring to the fat fraction of the specific food). Natural
mixed tocopherols are also used as dietary supplements.
The application covers phytosterol esters produced from vegetable oil (soybean
oil). Phytosterol esters are currently commercially available in selected foods
in several EU countries. The EU regulations limit exposure to a maximum of 3
grams per day of phytosterols through labelling requirements and maximum
concentrations in certain food categories in order to avoid intakes above the
recommended limits from multiple sources of intake. Plant sterols under
consideration are derived from soybean oil deodorised distillates.
Considering the information provided by the applicant regarding the starting
material, the subsequent production process, and the demonstration of low
residual protein content, the Panel of the European Food Safety Authority
considers that it is unlikely that natural mixed tocopherol/D-alpha tocopherols
from soybean sources and vegetable oils derived phytosterols and phytosterol
esters from soybean sources will trigger a severe allergic reaction in
susceptible individuals. The mixed tocopherols from soybean will therefore
exempted from labelling of allergy warning.
[2143]
Since wheat is relevant both as a source of epitopes known to induce coeliac
disease and as a source of allergens triggering wheat allergy, it is
appropriate to investigate wheat products, namely wheat starch hydrolysates,
for their potential to induce coeliac disease or trigger wheat allergy.
The Association des Amidonneries de Cereales de l'Union Europeenne AAC provides
information on wheat starch hydrolysates, particularly concerning the potential
effects of wheat-based glucose syrups including dextrose in coeliac disease and
wheat allergy. The history of safe use of wheat-based glucose syrups including
dextrose is claimed based on the safe use of wheat starch-based gluten-free
diet in coeliac disease.
Wheat-based glucose syrups including dextrose may contain low levels of
proteins and peptides. It is not known at which levels of intake glucose syrups
including dextrose would cause allergic reactions in wheat-allergic
individuals. Nevertheless, taking into account all the scientific information
provided and in particular the levels of wheat proteins reported in glucose
syrups including dextrose, the Panel considers that it is not very likely that
this product will trigger a severe allergic reaction in susceptible
individuals.
For coeliac disease, assessment of the evidence provided including a new
clinical study indicates that wheat-based glucose syrup is unlikely to cause an
adverse reaction in individuals with coeliac disease provided that the
(provisional) value of gluten considered by Codex Alimentarius for foods
rendered gluten-free is not exceeded.
The Codex Standard for Gluten-Free Foods (Codex Stan 118-1983) specifies that
the nitrogen content of food ingredients derived from gluten containing cereals
may not exceed 0.05 g per 100 g on a dry basis (or 0.31 % protein/ds, Nx6.25),
when they are used in a gluten-free food. [2144]
[2145]
BfR recommends strictly limiting levels in leather goods.
Studies by the regulatory authorities of the federal states reveal that many
leather goods like gloves, shoes or watch straps which come into direct contact
with the skin contain high levels of chromium (VI). Hexavalent chromium is a
strong allergen and it can lead to allergic skin reactions like contact eczema
in sensitised individuals.
Clinical picture of Chromium VI allergy
The typical clinical picture is allergic contact eczema on the areas of the
skin which come into contact with chromium (VI). Clothing which has direct skin
contact should not, therefore, contain any chromium (VI).
Even the lowest levels of chromium (VI) in leather are sufficient to trigger an
allergic reaction in hypersensitive individuals. At a level of 5 mg per kg
leather half of the sensitised individuals already manifested allergic skin
reactions like for instance contact eczema. The only effective protection for
them against skin disorders is to avoid any contact with products containing
chromium (VI).
Regulation
At the present time the chromium content of leather goods has not been
regulated by law apart from industrial safety provisions. In 2006 a DIN
standard stipulated that the chromium (VI) levels in work gloves must be below
the detection limit of three milligrams chromium (VI) per kilogram leather.
In more than 50% of leather goods such as gloves and shoes and other ware
which is worn close to the skin like watch straps, chromium IV was found up to
10 mg/kg
Tanning processing of hides
Normally, chromium (III) sulphate is used as the tanning agent. Chromium (VI)
either appears as an impurity in the tanning substance or it is formed through
oxidation from chromium (III) in the ensuing processing stages. There are
methods available which can considerably reduce the chromium levels in the
leather or even completely remove the chromium (VI). Chromium-free tanning
methods are another option.
Chromium free leather processing or mandatory declaration
The BfR believes that leather goods that come into contact with skin should
not, if possible, contain any chromium (VI). At the very least, the levels
should be reduced as far as possible. At the present time, the analytical
detection limit is approximately 3 mg per kg leather. The studies by the
regulatory authorities and the standard for work gloves prove that this limit
can be complied with by using the corresponding technologies.
On the other hand, mandatory declaration could help allergy sufferers to
consciously avoid purchasing products containing chromium (VI).
OurFood (c) 1998 - 2008 by Karl Heinz Wilm - Imprint (Impressum)