ALICOM 99/15

Conference on International Food Trade
Beyond 2000: Science-Based Decisions, Harmonization, Equivalence
and Mutual Recognition
Melbourne, Australia, 11-15 October 1999

Prospects for the Future: Emerging Problems - Food Allergens


Steve L. Taylor, Ph.D., University of Nebraska, USA


Table of Contents

1. Food allergies have probably affected mankind since the dawn of time. Centuries ago, the Roman philosopher, Lucretius, said "The food of one may be poison to another". The first well recorded case histories of food-allergic patients appeared in the early part of the 20th century. Yet, food allergies were largely ignored by the medical community and regulatory authorities until recent years. Even today, the prevalence of food allergies and their overall impact on individuals is not clearly understood in many parts of the world. In recent years, food allergies have become more widely recognized by the medical community particularly in North America, Europe, Japan, and Australia. However, food allergies likely affect some individuals in all countries of the world. Since the outcome of inadvertent exposure to the offending food can be extremely serious and even deadly for some food-allergic individuals, the impact of food allergies on public health should be given greater consideration by regulatory authorities than is currently the case.

2. In this paper, I will provide basic background information on the various types of food allergies and sensitivities including a description of the symptoms suffered by individuals with food allergies, an explanation of the mechanisms of the several illnesses within this category, and an estimate of the prevalence of food allergies. Then, I will focus on some of the regulatory issues that surround this issue including some recommendations for follow-up actions by FAO/WHO/WTO and Member Governments.

I. Introduction and Classification

3. A food sensitivity is defined as an abnormal physiologic response to a particular food. This same food is safe for the vast majority of consumers to ingest. Food sensitivities can be divided into two major categories: food allergies and food intolerances. Many consumers and even some medical professionals are likely to refer to any abnormal response to one or more specific foods as a food allergy regardless of the mechanism involved in the reaction. However, in fact, food sensitivities can involve several different types of mechanisms. There are practical reasons to distinguish between true food allergies and food intolerances from both a clinical and regulatory perspective.

4. Food allergies are abnormal responses of the immune system to certain components of foods. The allergens in foods are typically naturally-occurring proteins. True food allergies can be further divided into two categories: immediate hypersensitivity reactions and delayed hypersensitivity reactions. In immediate hypersensitivity reactions, symptoms begin to develop within minutes to an hour or so after ingestion of even minute amounts of the offending food. Immediate hypersensitivity reactions have been noted with more than 170 different foods. Basically, any food that contains protein has the potential to elicit allergic sensitization in someone in the population. The reactions involved in immediate hypersensitivities can sometimes be quite severe. The mechanism of immediate hypersensitivity reactions will be described below. In contrast, the symptoms associated with delayed hypersensitivity reactions do not begin to appear until 24 hours or longer after ingestion of the offending food. The role of delayed hypersensitivity reactions in adverse reactions to foods remains rather poorly defined with the exception of celiac disease (see below). The symptoms of delayed hypersensitivity reactions do not reach the level of severity involved in the more severe cases of immediate hypersensitivity reactions. However, the level of tolerance for the offending food is also very low for delayed hypersensitivity reactions.

5. Like true food allergies, food intolerances affect a limited number of individuals. Food intolerances can be defined as any form of food sensitivity that does not involve immunologic mechanisms. There are three major classifications of food intolerances: (1) metabolic food disorders, anaphylactoid reactions, and idiosyncratic reactions. The mechanisms involved in these illnesses are described below. For the most part, food intolerances involve less severe manifestations and affected individuals can frequently tolerate some of the offending food in their diets.

6. From a practical viewpoint, true food allergies should be distinguished from other types of food sensitivities because they can elicit serious adverse reactions in some individuals and because individuals with food allergies can tolerate little of the offending food in their diets. For example, it is important to distinguish between milk allergy and lactose intolerance. Milk allergy can involve systemic and sometimes serious reactions, and individuals with milk allergy can tolerate little milk in their diets. In contrast, lactose intolerance, which results from an enzyme deficiency in the small intestine, involves only gastrointestinal symptoms, and affected individuals can often tolerate appreciable quantities of milk in their diets.

II. Characteristics of the Various Types of Food Sensitivities


7. Immediate hypersensitivity reactions are mediated by a specific class of antibodies known as immunoglobulin E or IgE. Although all humans have low levels of IgE antibodies, only individuals predisposed to the development of allergies produce IgE antibodies that are specific for and recognize certain environmental antigens or allergens. These antigens or allergens are typically proteins, although only a few of the many proteins found in nature are capable of acting as allergens by stimulating the production of specific IgE antibodies in susceptible individuals. Exposure to these particular food allergens elicits the formation of specific IgE antibodies by B cells that exist in many tissues including the intestinal tract. The IgE antibodies attach to mast cells in various tissues and basophils in the blood. At this point, the affected individual is sensitized to the particular food but has not yet experienced an allergic reaction. Upon subsequent exposure to the allergenic substance in the offending food, the allergen interacts with the specific IgE antibodies on the surface of the mast cell or basophil stimulating the release of a host of mediators of the allergic response into the tissues and blood. Although many mediators have been described, histamine is one of the primary mediators responsible for many of the immediate symptoms that occur in such reactions. The interaction of small amounts of the allergen with the mast cell-bound IgE antibodies triggers the release of massive quantities of these mediators. For this reason, ingestion of a small amount of the offending food can elicit an allergic reaction in a sensitive individual.

8. A wide variety of symptoms, ranging from mild to life-threatening, can be associated with IgE-mediated allergies. The symptoms can involve the gastrointestinal tract (nausea, vomiting, diarrhea, abdominal cramping), the skin (urticaria or hives, dermatitis, eczema, angioedema, pruritis or itching), or the respiratory tract (rhinitis, asthma, laryngeal edema). Individuals with food allergies usually suffer from just a few of the many possible symptoms. Gastrointestinal symptoms are fairly common because foods are ingested and the gastrointestinal tract is the initial organ of insult. Cutaneous responses are also common manifestations of food allergies. Respiratory reactions are less common with food allergies than they are with environmental allergies such as pollen or animal dander allergies in which cases the allergens are primarily inhaled. However, asthma is among the more severe symptoms associated with food allergies, although food-induced asthma is relatively rare.

9. Perhaps the most common manifestation of food allergy is the so-called oral allergy syndrome, which is so mild that it is sometimes ignored even by its sufferers. Oral allergy syndrome is confined to symptoms in the oropharyngeal area, including itching, hives, and swelling. It is most frequently associated with the ingestion of fresh fruits and vegetables. Because the allergens in these foods are inactivated on contact with stomach acid, systemic reactions are rarely encountered.

10. The most frightening symptom associated with food allergies is anaphylactic shock. Anaphylactic shock involves the gastrointestinal tract, the skin, the respiratory tract, and the cardiovascular system, with symptoms often occurring in combination and developing rapidly. Severe hypotension can occur, and death can ensue within minutes of ingestion of the offending food without proper treatment. Only a few people with food allergies are at risk of such serious consequences, but numerous deaths resulting from inadvertent exposure to the offending food have been documented among individuals with food allergies.

11. IgE-mediated food allergies affect between 1% and 2% of the total population. However, infants and young children are more commonly affected by food allergies than other age groups. Among infants younger than 3 years, the prevalence of food allergies appears to be in the range of 5% to 8%. In some countries, a much higher percentage of the population believes that they have food allergies because of self-diagnosis, parental diagnosis, and misconceptions and misdiagnosis by some physicians.

12. Most IgE-mediated food allergies are attributable to a small group of 8 foods or food groups, sometimes referred to as "the Big Eight": cows' milk, eggs, fish, crustaceans, peanuts, soybeans, tree nuts, and wheat. It is estimated that these foods or food groups account for more than 90% of all food allergies in the U.S. In 1995, a FAO Technical Consultation listed these foods as the most common causes of food allergy on a worldwide basis. Several collective terms are used to describe food groups. For the purposes of food allergies, crustaceans include shrimp, prawns, crab, lobster, and crayfish. Fish refers to all species of finfish, both freshwater and salt water. Tree nuts comprise almonds, walnuts, pecans, cashews, Brazil nuts, hazelnuts, pistachios, pine nuts, macadamia nuts, chestnuts, and hickory nuts. Overall, more than 170 foods have been documented to cause food allergies. Several additional foods are worthy of specific mention because, although they less frequently cause allergies, they have been known to cause severe reactions. These foods include molluscan shellfish (clams, oysters, etc.), sesame seeds, poppy seeds, sunflower seeds, cottonseed, and certain other legumes (the various types of dry beans, peas, lentils, lupin, and garbanzo beans). The allergens involved in IgE-mediated food allergies are specific naturally-occurring proteins that exist in that particular food. Only one or a few of the many proteins found in each of these foods is capable of acting as an allergen.

13. The prevalence of allergies to specific foods is not precisely known. Cows' milk allergy is most common in infancy and is often outgrown. Studies in several countries have indicated that the prevalence of cows' milk allergy among young infants is about 2%. Several recent studies have shown that the prevalence of peanut allergy may be as high as 1% in the U.S. and 0.5% in England. The prevalence of peanut allergy may be lower in England because British consumers, until recently, did not eat peanuts as frequently in their diets as Americans. However, peanut consumption has risen in England in recent years and peanut allergy also appears to be increasing in prevalence in England.

14. Although the symptoms of food allergies can be treated with certain drugs including antihistamines and epinephrine, the only prophylactic approach to the treatment of food allergies is the specific-avoidance diet. For example, those who are allergic to peanuts must avoid ingesting peanuts. However, the construction and implementation of safe and effective avoidance diets is often a challenge for individuals with food allergies. These individuals must avoid all forms of the offending food that contain protein because the allergens are found in the protein fraction. For example, cows' milk-allergic individuals would need to avoid all dairy products and most dairy ingredients such as casein and whey. The ingredient statement on the label of packaged foods provides critical information to food-allergic consumers.

15. Individuals with IgE-mediated allergic reactions to foods will experience symptoms on exposure to small amounts of the offending food. The interaction of a small amount of allergen with IgE antibodies on the surface of the mast cell releases massive quantities of mediators, which accounts for the low degree of tolerance. The precise threshold doses for allergenic foods are unknown, exposure to as little as 1-2 mg of the offending food will elicit allergic reactions in the most sensitive individuals. The severity of the symptoms experienced by the allergic individual will likely increase as the dose of exposure increases.

16. Despite careful reading of food ingredient statements, food-allergic individuals can suffer allergic reactions as the result of the "hidden" presence of the offending food in the product that they are ingesting. The use of the 25% rule allows allergenic food components to be present unlabelled in food products at rather significant levels in comparison to the minimal threshold dose for reactions. Occasionally, food ingredients are derived from allergenic sources materials that may contain residues of the proteinaceous allergens from those sources. Furthermore, these ingredients are often listed on the ingredient statement under collective terms, and the source of the ingredient is not revealed to the consumer. Examples would include flavours, spices, oils, starch, or lecithin. These ingredients, even if derived from allergenic sources, will not always contain residues of the allergens. For example, highly refined vegetable oils including peanut and soybean oils, contain extraordinarily low amounts of proteins from the source material and do not elicit allergic reactions in sensitive individuals. Unexpected residues of allergenic foods occasionally occur in foods are the result of industry errors such as formulation mistakes, packaging mix-ups, the unwise use of re-work, or inadequate cleaning of shared equipment. Although such errors occur infrequently, they can have serious consequences.

17. Because of the severity of symptoms involved in IgE-mediated food allergies in some affected individuals and because of the likelihood of adverse reactions from ingestion of trace amounts of these allergenic foods, IgE-mediated food allergies merit the highest degree of attention from regulatory authorities.


18. Delayed hypersensitivity reactions are mediated by tissue-bound immune cells. The only well described example of a delayed hypersensitivity reaction to foods is celiac disease. Celiac disease, also known as celiac sprue or gluten-sensitive enteropathy, occurs in certain individuals following the ingestion of wheat, rye, barley, related grains (notably spelt, kamut, and triticale), and perhaps oats. Celiac disease results from an abnormal response of the T lymphocytes in the small intestine to particular proteins (gluten from wheat and related proteins from the other grains) found in these cereal grains. An inflammatory process ensues and the absorptive epithelium of the small intestine becomes damaged. The tissue damage is localised to the small intestine but the disruption of the absorptive process affects many other physiological functions.

19. The symptoms of celiac disease are reflective of a malabsorption syndrome and include diarrhea, bloating, weight loss, anemia, bone pain, chronic fatigue, weakness, muscle cramps, and, in children, failure to gain weight and growth retardation. Considerable variability exists in the severity of celiac disease among patients with the illness. Some celiac sufferers experience few symptoms, and latent, asymptomatic celiac disease has been described along with concern that the latent illness may progress to the symptomatic illness if not recognized and treated. The symptoms develop 24 - 72 hours after ingestion of the offending food, because the intestinal damage caused by the inflammatory process takes some time to occur. The symptoms of celiac disease are likely to persist for some days even with avoidance of the offending food because the intestinal damage must be repaired by the body to return to normal functioning. Deaths resulting directly from the acute phase of celiac disease have not been reported. However, patients with celiac disease have a 50 - 100-fold increased risk of developing malignant lymphomas. A lifelong avoidance of the offending foods may be necessary to lessen this chronic risk.

20. The prevalence of celiac disease appears to vary from one country to another. The differences may be related in part to the method of diagnosis used in a particular country and the likelihood of recognition of latent celiac disease. The prevalence in some European countries and regions approaches 1 in 250 persons, while the prevalence in the U.S. appears to be approximately 1 in 2000 to 3000 persons. Celiac disease is an inherited trait that occurs most commonly in European populations and their descendents in other countries. Celiac disease rarely occurs in Asian or African populations.

21. The treatment for celiac disease involves the total avoidance of wheat, rye, barley, and oats and all products made from these grains. Treatment with a gluten-free diet results in significant improvement of the intestinal mucosa and its absorptive function. Celiac sufferers are thought to react to ingestion of trace amounts of the offending food, although the threshold dose has not been carefully established. As with IgE-mediated food allergies, the cereal grains involved in celiac disease can be "hidden" in foods as a result of the lack of source labelling of certain ingredients, the failure to declare certain ingredients based upon regulations such as the 25% rule, and various inadvertent errors made by food manufacturers.

22. Celiac disease also merits serious attention by regulatory authorities. Although the symptoms are less serious, the morbidity of this illness is considerable unless strict adherence to a gluten-free diet can be achieved.


23. Metabolic food disorders result from defects in the ability to metabolize a food component. Metabolic food disorders are often a genetically acquired defect. The best examples of food-related metabolic food disorders are lactose intolerance and favism.

24. Lactose intolerance results from an inherited deficiency of the enzyme, lactase or b-galactosidase, in the intestinal mucosa. As a result, lactose, a dissaccharide and the primary sugar in milk and milk products, cannot be metabolised into constituent monosaccharides, galactose and glucose. While these monosaccharides can be absorbed by the intestine and used by the body for energy, undigested lactose cannot be absorbed by the small intestine and passes into the colon, where bacteria metabolize the lactose into CO2 and H2O. The symptoms characteristic of lactose intolerance include bloating, flatulence, abdominal cramping, and frothy diarrhea. Lactose intolerance affects a large number of people worldwide. Lactose intolerance is more frequent among certain ethnic groups (African Americans, Native Americans, Hispanics, Asians, certain Jewish groups, and Arabs) affecting as many as 60 - 90% of older adults in those groups. The prevalence among Caucasians is about 6 - 12%. The symptoms of lactose intolerance may rarely be present at birth, but can begin to develop as early as the childhood years as the level of activity of intestinal lactase decreases. The illness is most prevalent among older age individuals within the population. The usual treatment for lactose intolerance is the avoidance of dairy products containing lactose. However, most individuals with lactose intolerance can tolerate some lactose in their diets because some activity of intestinal lactase remains. Often, they can ingest several ounces of milk without developing symptoms. Thus, the development of avoidance diets is simpler for individuals with lactose intolerance because exposure to very small amounts of lactose resulting from labelling practices or industry errors is unlikely to elicit adverse reactions. Because of the mild symptoms involved in lactose intolerance and the demonstrated tolerance for small amounts of lactose among sensitive individuals, regulatory authorities do not need to be as vigilant about this particular type of food sensitivity.

25. Favism is an intolerance to the consumption of fava beans or the inhalation of pollen from the Vicia faba plant. Favism affects individuals with an inherited deficiency of erythrocyte glucose-6-phosphate dehydrogenase (G6PDH). G6PDH is a critical enzyme to prevention of oxidative damage to erythrocyte membranes. Fava beans contain several naturally occurring oxidants, including vicine and convicine, that are capable of damaging erythrocyte membranes in G6PDH-deficient individuals. The result is acute hemolytic anemia with pallor, fatigue, dyspnea, nausea, abdominal and/or back pain, fever, and chills. In rare cases, more serious symptoms occur such as hemoglobinuria, jaundice, and renal failure. The onset time is quite rapid, usually occurring 5 - 24 hours after ingestion. Favism is a self-limiting illness with a prompt and spontaneous recovery assuming no further exposure. G6PDH deficiency is an inherited trait occurring very commonly among Oriental and Jewish communities in Israel, Sardinians, Cypriot Greeks, American blacks, and certain African populations. The trait is virtually non-existent in northern European populations, Native Americans, and Eskimos. G6PDH deficiency affect an estimated 100 million individuals worldwide. However, many of these individuals are never exposed to fava beans. Favism is most prevalent when the Vicia fava plant is in bloom, causing elevated levels of airborne pollen, and when the fava beans are available in the market. But, these beans are not commonly consumed in many parts of the world. Avoidance is the primary strategy for treatment of favism. The threshold doses for fava beans among sensitive individuals is unknown. Regulatory attention to favism is probably not necessary except in those parts of the world where fava beans are routinely available in the marketplace.


26. Anaphylactoid reactions are caused by substances in foods that bring about the non-immunologic release of chemical mediators from mast cells. While the mediators are the same as in IgE-mediated allergies, the mechanism does not involve IgE antibodies. Only circumstantial evidence exists to support the involvement of this mechanism in food sensitivities. Supposedly, some foodborne chemicals are able to destabilise mast cell membranes and allow the spontaneous release of histamine and other mediators. However, none of these histamine-releasing substances in foods have been identified.


27. Idiosyncratic reactions refer to adverse reactions to food experienced by certain individuals through which the mechanism is unknown. The cause-and-effect relationship between specific foods and food ingredients and these idiosyncratic illnesses is often poorly defined. While numerous mechanisms could possibly occur, none have been proven. In a few cases, the role of foods in a specific type of idiosyncratic reaction is well documented.

28. Sulfite-induced asthma is a good example of a well established food idiosyncrasy. The role of sulfites in the causation of asthma in a small proportion of the asthmatic population (an estimated 1 - 2% of all asthmatics) has been well documented by double-blind, placebo-controlled clinical trials. However, the mechanism of the illness remains unknown. The relationship of other symptoms to ingestion of sulfites, while alleged in some reports, has not been proven. Sulfite are common food additives used for a number of different technical functions. Exposure to sulfites can occur through a number of common foods including wines, corn starch, dehydrated fruits and vegetables, and many others. Sulfite-sensitive individuals must avoid certain sulfited foods and beverages, as the adverse reaction can be serious and even fatal. However, sulfite-sensitive individuals can tolerate small amounts of sulfites in their diets, although the threshold for sulfites varies from one person to another. In the U.S. and several other countries, regulatory authorities have mandated the labelling of sulfites when residual levels of SO2 exceed 10 ppm. This labelsling strategy appears to protect the sulfite-sensitive segment of the population.


29. Sometimes, allergy-like intoxications primarily histamine poisoning also known as scombroid fish poisoning are included in discussions of food allergies and sensitivities. However, histamine poisoning is not a true food sensitivity since it can affect all persons. The confusion stems from the fact that histamine poisoning causes allergy-like symptoms, which should not be surprising, since histamine is one of the principal mediators of IgE-mediated food allergies. In the case of IgE-mediated food allergies, histamine is released from mast cells in vivo. Histamine poisoning is the result of the ingestion of foods containing high levels of histamine. Since histamine poisoning is not a true food sensitivity, it will not be discussed further here. However, regulatory authorities do have the responsibility to control histamine poisoning.

III. Recommendations to FAO, WHO, WTO
and Member Governments


30. Allergens in foods have been considered by the Codex Committee on Food Labelling (CCFL) on a number of occasions beginning in 1993 when a working paper on the consideration of potential allergens in foods was prepared by Norway, in cooperation with Finland, Iceland, and Sweden (Ref: CX/FL 93/5). The CCFL, working through FAO, convened an FAO Technical Consultation on Food Allergies in Rome in 1995. This FAO Technical Consultation was asked inter alia to "provide guidance on the development of science-based criteria to determine which foods or food products should be placed on a list of those foods or food products whose presence should always be declared in the list of ingredients on a food label, because of their allergenic properties". The Consultation confirmed that the listing of foods and ingredients known to cause food allergies and intolerances that had been developed by CCFL was appropriate with some modifications.

31. The revised list of those foods and ingredients that are known to cause hypersensitivity and should always be declared were identified as the following:

32. Subsequent debate occurred within CCFL over the ensuing years, but this list has now been adopted as a final text by the Codex Alimentarius Commission (CAC) in June 1999, with the understanding that future additions and/or deletions from the list will be considered by the CCFL taking into account advice received from JECFA.

33. Furthermore, the CCFL has been debating the 25% rule and considering whether to recommend a 5% rule in its place. This recommendation (i.e., 5%) was also adopted by the CAC in June 1999. The FAO Technical Consultation in 1995 had recommended to the CCFL that the 25% rule be modified to a 5% rule to provide allergic consumers with increased assurance that allergenic food components would be declared on product labels.

34. During the CCFL debate, further questions have arisen that require advice from the Joint FAO/WHO Expert Committee on Food Additives (JECFA), the committee that provides scientific recommendations to the Codex Alimentarius Commission relating to food additives and ingredients in foods. As a result, WHO convened a Food Allergens Labelling Panel in Geneva in February, 1999 to provide guidance to JECFA on certain specific issues related to food allergies and intolerances. Specifically, this Panel was asked to provide input on the following issues:

35. The Panel reached several recommendations. With respect to criteria for the addition of foodstuffs to the Codex list of common allergenic foods, the Panel recommended that the following criteria be applied:

i) The existence of a credible cause-and-effect relationship based upon positive double-blind, placebo-controlled food challenge or unequivocal reports of reactions with typical features of severe allergic or intolerance reactions.

ii) There should be reports of severe systemic reactions following exposure to the foodstuff.

iii) Whereas the Panel recognized the ideal criterion would be prevalence data in children and adults, supported by appropriate clinical studies, i.e. a double-blind, placebo-controlled food challenged from the general population of several countries, it noted that currently such information is only available (1) for infants, (2) in some countries, and (3)for some foodstuffs. Such information is rarely available for adults. As an alternative, the Panel agreed that the use of such available data (e.g. comparative prevalence of the specific food allergy in groups of allergy patients from several countries backed up ideally by a double-blind, placebo-controlled food challenge) would be appropriate.

36. The Panel also recognized that the application of these criteria would be reliant upon expert advice. It therefore considered that such advice would be provided best by a body which, because of geographical variation in food allergy and in diets, should be constituted as to have representation from a variety of disciplines and global regions.

37. The Panel also discussed the list adopted by CCFL that included not only allergenic foods but also products of these. The Panel discussed whether this definition was too broad and includes products that are not allergenic because they do not contain sufficient amounts of allergenic proteins to elicit a reaction. However, with the current available data, the Panel concluded that it was not possible to set a limit on the amount of protein necessary to elicit an allergic reaction. The Panel recommended that:

i) Products of allergenic foods on the CCFL list must always be labelled as such unless they are included in a list of products that are excluded from the need for labelling of the food source.

38. Criteria for the entry of a product on this list are:

i) evidence that a clinical study using double-blind, placebo-controlled food challenge has confirmed that the specific product does not elicit allergic reaction is a group of patients with clinical allergy to the parent foodstuff;

ii) specifications for the product and its manufacturing process which demonstrates the process's ability to yield a consistently safe product.

39. To the knowledge of the Panel, only two products may currently fulfill these criteria and these are highly refined peanut and soybean oils. The Panel recommended that these two products be reviewed at the next meeting of JECFA.

40. JECFA debated these recommendations, including an assessment of the allergenicity of highly refined peanut and soybean oils, at its meeting in the summer of 1999. As this paper was being drafted, the final report of the JECFA meeting had not yet been published.

IV. Recommendations

41. FAO, WHO, WTO, and Member Governments must continue to recognize the importance of food allergies and intolerances to the health and well-being of a small, but significant, proportion of the consuming public. The deliberative process involving CCFL, JECFA, CAC, and various special panels and consultations must continue as necessary to provide governments with recommended actions for the protection of food-allergic segment of the population. Clearly, labelling is the key to the implementation of safe and effective avoidance diets by individuals with food allergies and intolerances. Government regulatory agencies must assure that the information on labels is sufficient to provide such individuals with the information that they seek and need.

42. In my personal opinion, the recommendations made by the CAC and JECFA in their 1999 meetings are reasonable. I would advocate that member governments do the following:

1) adopt the list of most common allergenic foods as adopted by the CAC and modify their labelling regulations to assure that these allergenic foods and their products shall always be declared when present in packaged foods

2) exclude highly refined peanut and soybean oils from these labelling requirements because these two products do not contain sufficient amounts of protein to elicit allergic reactions.

3) support the adoption made by the CAC in modifying the 25% rule to a 5% rule and then adopt the new rule.

43. With respect to FAO, WHO, WTO, and the Member Governments, I would make the following recommendations:

1) Because the issues surrounding food allergies and intolerances require advice from individuals with specialized experience, an expert subcommittee or panel on food allergies and intolerances should be constituted to provide guidance to JECFA on such issues.

2) A mechanism such as that recommended by the Food Allergens Labelling Panel should be developed to provide guidance on the addition of specific foods or food ingredients to the Codex list of common allergenic foods. Arguments have already been made for the addition of sesame seeds to the list. Expert judgment is required to determine if sufficient data exist to warrant such recommendations. The expert judgments could be provided by the expert panel recommended in point 1, above.

3) A mechanism such as that recommended by the Food Allergens Labelling Panel should be developed to provide guidance on which products could be excluded from source labelling. Criteria must be established for these decisions. Expert judgment will be required to determine if the scientific basis exists to allow an exclusion from the labelling criteria related to "products of these". Again, the expert judgments could be provided by the expert panel recommended in point 1, above. Several existing ingredients might be considered for such exclusions including peanut oil, soybean oil, butter, butterfat, and butter oil (from milk), lysozyme (from eggs), fish gelatin, various tree nut oils, and chitin (from crustacea).

4) Highly refined peanut and soybean oils should be excluded from the source labelling provisions. Sufficient data already exist to support that recommendation.

5) The 25% rule should be abolished in favour of labelling regulations that mandate the declaration of intentionally added ingredients with the exception of several broad collective categories such as flavours, spices, starch, oils, etc. The adopted 5% rule is not sufficient to protect food-allergic individuals, although it is an improvement over the 25% rule. Even if the foods and ingredients from commonly allergenic sources (the Codex list) are always labelled, there are over 160 other known allergenic foods. While allergies to these foods are not sufficiently common to be placed on the Codex list, smaller numbers of consumers do wish to avoid these foods due to allergic sensitization.

6) The CCFL may wish to consider making recommendations with respect to the use of precautionary labelling. Several countries (e.g. Canada, United Kingdom) already allow the use of precautionary labelling on foods where manufacturing processes may occasionally allow the presence of undeclared residues of allergenic foods from use of shared equipment, re-work practices, etc. Since such manufacturing practices are widespread, the use of precautionary labelling can affect many packaged food products. If such practices are allowed, numerous foods can be removed from the diets of food-allergic individuals. Some of these restrictions may be unnecessary if the food does not actually contain sufficient residues of the allergens to elicit reactions in sensitive consumers. Also, many forms of the precautionary labelling statements have appeared on packages. Examples include: "may contain", "may contain nut traces", "manufactured on the same equipment as", "manufactured in the same facility as". A greater degree of uniformity in these statements might prevent some consumer confusion. Clearly, this is a new issue for CCFL. An expert panel or technical consultation could be convened to provide recommendations to CCFL for further deliberations.

7) FAO and/or WHO should consider the establishment of an international collaborating centre on food allergies and intolerances. This centre could accumulate and organize published information on food allergies and intolerances. The centre could provide authoritative reviews that would be useful to the expert panel recommended in point 1, above. The center could serve as a resource to various member governments seeking information on specific types of food allergies. The Food Allergy Research & Resource Programme at the University of Nebraska has already established an extensive computerized database of existing scientific and medical literature on food allergies and intolerances.

V. Future Issues

44. The entire issue of food allergies and intolerances has emerged rather recently. Many of the recommendations outlined above have yet to be fully implemented by Member Governments, although they have received considerable attention from FAO and WHO in recent years. Several new issues are clearly emerging. Precautionary labelling has already been identified as one such issue above. Although it is not clear that FAO and WHO should become involved in the issue of precautionary labelling, the volume of global trade in packaged foods and the lack of uniformity in precautionary labelling statements from one country to another certainly mandates that some consideration be given to involvement by FAO and WHO in this issue.

45. Another emerging issue relates to genetically-modified foods. GMO foods usually contain a few novel proteins by comparison to the traditional food from which they were derived. There is certainly some possibility that one or more of these novel proteins could be or become food allergens. This possibility has been widely recognized and was addressed as part of the 1996 FAO/WHO Expert Consultation on Biotechnology and Food Safety. However, the assessment of the potential allergenicity of GMO foods continues to be refined and debated. This issue will likely need to be addressed again by FAO and WHO in the future and should perhaps be the singular focus of a future expert consultation.