Samuel Benrejeb Godefroy

A population-based study on peanut, tree nut, fish, shellfish, and sesame allergy prevalence in Canada

BACKGROUND Recent studies suggest an increased prevalence of food-induced allergy and an increased incidence of food-related anaphylaxis. However, prevalence estimates of food allergies vary considerably between studies. OBJECTIVES To determine the prevalence of peanut, tree nut, fish, shellfish, and sesame allergy in Canada. METHODS Using comparable methodology to Sicherer et al in the United States in 2002, we performed a cross-Canada, random telephone survey. Food allergy was defined as perceived (based on self-report), probable (based on convincing history or self-report of physician diagnosis), or confirmed (based on history and evidence of confirmatory tests). RESULTS Of 10,596 households surveyed in 2008 and 2009, 3666 responded (34.6% participation rate), of which 3613 completed the entire interview, representing 9667 individuals. The prevalence of perceived peanut allergy was 1.00% (95% CI, 0.80%-1.20%); tree nut, 1.22% (95% CI, 1.00%-1.44%); fish, 0.51% (95% CI, 0.37%-0.65%); shellfish, 1.60% (95% CI, 1.35%-1.86%); and sesame, 0.10% (95% CI, 0.04%-0.17%). The prevalence of probable allergy was 0.93% (95% CI, 0.74%-1.12%); 1.14% (95% CI, 0.92%-1.35%); 0.48% (95% CI, 0.34%-0.61%); 1.42% (95% CI, 1.18%-1.66%); and 0.09% (95% CI, 0.03%-0.15%), respectively. Because of the infrequency of confirmatory tests and the difficulty in obtaining results if performed, the prevalence of confirmed allergy was much lower. CONCLUSION This is the first nationwide Canadian study to determine the prevalence of severe food allergies. Our results indicate disparities between perceived and confirmed food allergy that might contribute to the wide range of published prevalence estimates.

Overall prevalence of self-reported food allergy in Canada

Estimate 1: Including all adults Peanut 1.77 (1.21-2.33) 0.78 (0.58-0.97) 1.00 (0.80-1.20) Tree nut 1.73 (1.16-2.30) 1.07 (0.84-1.30) 1.22 (1.00-1.44) Fish 0.18 (0.00-0.36) 0.60 (0.43-0.78) 0.51 (0.37-0.65) Shellfish 0.55 (0.21-0.88) 1.91 (1.60-2.23) 1.60 (1.35-1.86) Sesame 0.23 (0.03-0.43) 0.07 (0.01-0.13) 0.10 (0.04-0.17) Milk 2.23 (1.51-2.95) 1.89 (1.56-2.21) 1.97 (1.64-2.29) Egg 1.23 (0.69-1.77) 0.67 (0.48-0.86) 0.80 (0.61-0.99) Wheat 0.45 (0.08-0.83) 0.86 (0.63-1.08) 0.77 (0.57-0.96) Soy 0.32 (0.08-0.55) 0.16 (0.07-0.25) 0.20 (0.10-0.30) Fruits 1.14 (0.68-1.60) 1.61 (1.32-1.89) 1.50 (1.25-1.75) Vegetables 0.45 (0.17-0.74) 1.29 (1.02-1.55) 1.10 (0.88-1.31) Other 1.32 (0.80-1.84) 1.67 (1.37-1.97) 1.59 (1.32-1.86) All foods 7.14 (5.92-8.36) 8.34 (7.69-8.99) 8.07 (7.47-8.67) Estimate 2: Excluding some adults All foods 7.14 (5.92-8.36) 6.56 (5.99-7.13) 6.69 (6.15-7.24) Estimate 3: Estimate 2 adjusted for nonresponse All foods 7.12 (6.07-8.28) 6.58 (6.22-6.96) 6.67 (6.19-7.17)

Introduction of oats in the diet of individuals with celiac disease: a systematic review

Celiac disease is an immune-mediated disease, triggered in genetically susceptible individuals by ingested gluten from wheat, rye, barley, and other closely related cereal grains. The only treatment for celiac disease is a strict gluten-free diet for life. This paper presents a systematic review of the scientific literature on the safety of pure oats for individuals with celiac disease, which historically has been subject to debate. Limitations identified within the scientific database include: limited data on long-term consumption, limited numbers of participants in challenge studies, and limited reporting about the reasons for withdrawals from study protocols. Furthermore, some evidence suggests that a small number of individuals with celiac disease may be intolerant to pure oats and some evidence from in vitro studies suggests that an immunological response to oat avenins can occur in the absence of clinical manifestations of celiac disease as well as suggesting that oat cultivars vary in toxicity. Based on the majority of the evidence provided in the scientific database, and despite the limitations, Health Canada and the Canadian Celiac Association (CCA) concluded that the majority of people with celiac disease can tolerate moderate amounts of pure oats. The incorporation of oats into a gluten-free diet provides high fiber and vitamin B content, increased palatability, and beneficial effects on cardiovascular health. However, it is recommended that individuals with celiac disease should have both initial and long-term assessments by a health professional when introducing pure oats into a gluten-free diet.

Living with coeliac disease and a gluten-free diet: a Canadian perspective

OBJECTIVE Strict adherence to a gluten-free diet is the only treatment for coeliac disease. The gluten-free diet is complex, costly and impacts on all activities involving food, making it difficult to maintain for a lifetime. The purpose of this cross-sectional study was to evaluate the difficulties experienced, the strategies used and the emotional impact of following a gluten-free diet among Canadians with coeliac disease. METHODS A questionnaire was mailed to all members (n = 10 693) of both the Canadian Celiac Association and the Fondation québécoise de la maladie cœliaque in 2008. RESULTS The overall response rate was 72%. Results are presented for the 5912 respondents (≥18 years) reporting biopsy-confirmed coeliac disease and/or dermatitis herpetiformis. Two-thirds never intentionally consumed gluten. Women reported significantly greater emotional responses to a gluten-free diet but, with time, were more accepting of it than men. Difficulties and negative emotions were experienced less frequently by those on the diet for >5 years, although food labelling and eating away from home remained very problematic. Frustration and isolation because of the diet were the most common negative emotions experienced. CONCLUSIONS The present study quantifies the difficulties experienced, the strategies used and the emotional impact of following a gluten-free diet. It highlights the need to improve the training and education of dietitians, other health providers and the food service industry workers about coeliac disease and a gluten-free diet, with the aim of better helping individuals improve their adherence to a gluten-free diet and their quality of life.

Role of food labels in accidental exposures in food-allergic individuals in Canada

BACKGROUND Little is known about the impact of food labeling on the allergic consumer. OBJECTIVE To determine the proportion of food-allergic individuals attributing an accidental exposure to inappropriate labeling, failure to read a food label, or ignoring a precautionary statement and to identify factors associated with accidental exposures. METHODS Food-allergic individuals or their caregivers were recruited from a Canadian registry of individuals with a physician-confirmed diagnosis of peanut allergy and from allergy awareness organizations. Participants completed questionnaires regarding accidental exposures due to specific food labeling issues. The association between accidental exposures and characteristics of food-allergic individuals or their caregivers was estimated using multivariate logistic regression models. RESULTS Of 1,862 potential participants, 1,454 (78.1%) responded. Of the 47.8% (95% confidence interval [CI], 45.1%-50.5%) of respondents who experienced an accidental exposure, 47.0% (95% CI, 43.1%-50.9%) attributed the event to inappropriate labeling, 28.6% (95% CI, 25.1%-32.2%) to failure to read a food label, and 8.3% (95% CI, 6.3%-10.7%) to ignoring a precautionary statement. Food-allergic individuals who were allergic to peanut, tree nut, fish, or shellfish were less likely to experience an accidental exposure due to the allergen not being identified in plain language. CONCLUSIONS A considerable proportion of accidental exposures are attributed to inappropriate labeling, failure to read labels, and ignoring precautionary statements. Clear and consistent labeling of food allergens combined with increased consumer education is necessary to improve consumer confidence and compliance and to reduce accidental exposures.

Challenges and trends in the determination of selected chemical contaminants and allergens in food

This article covers challenges and trends in the determination of some major food chemical contaminants and allergens, which—among others—are being monitored by Health Canada’s Food Directorate and for which background levels in food and human exposure are being analyzed and calculated. Eleven different contaminants/contaminant groups and allergens have been selected for detailed discussion in this paper. They occur in foods as a result of: use as a food additive or ingredient; processing-induced reactions; food packaging migration; deliberate adulteration; and/or presence as a chemical contaminant or natural toxin in the environment. Examples include acrylamide as a food-processing-induced contaminant, bisphenol A as a food packaging-derived chemical, melamine and related compounds as food adulterants and persistent organic pollutants, and perchlorate as an environmental contaminant. Ochratoxin A, fumonisins, and paralytic shellfish poisoning toxins are examples of naturally occurring toxins whereas sulfites, peanuts, and milk exemplify common allergenic food additives/ingredients. To deal with the increasing number of sample matrices and analytes of interest, two analytical approaches have become increasingly prevalent. The first has been the development of rapid screening methods for a variety of analytes based on immunochemical techniques, utilizing ELISA or surface plasmon resonance technology. The second is the development of highly sophisticated multi-analyte methods based on liquid chromatography coupled with multiple-stage mass spectrometry for identification and simultaneous quantification of a wide range of contaminants, often with much less requirement for tedious cleanup procedures. Whereas rapid screening methods enable testing of large numbers of samples, the multi analyte mass spectrometric methods enable full quantification with confirmation of the analytes of interest. Both approaches are useful when gathering surveillance data to determine occurrence and background levels of both recognized and newly identified contaminants in foods in order to estimate human daily intake for health risk assessment.

Emerging analytical methods to determine gluten markers in processed foods—method development in support of standard setting

The availability of analytical methods to detect and determine levels of markers of priority allergens in foods is of the utmost importance to support standard setting initiatives, the development of compliance and enforcement activities, as well as to provide guidance to industry on implementation of quality control practices, ensuring the effectiveness of allergen-related sanitation techniques. This paper describes the development and implementation of a mass-spectrometry-based technique to determine markers for individual sources of gluten in beer products. This methodology was shown to answer the requirements of Health Canada’s proposed labeling standard for individual gluten source declaration, in order to achieve its policy objectives (i.e., protection of sensitive consumers, while promoting choice). Minimal sample work-up was required and the results obtained by ELISA were further complemented using the LC-MS/MS method. This paper aims to demonstrate the feasibility of alternative techniques to ELISA-based methodologies to determine allergen and gluten markers in food.

Clinical features and symptom recovery on a gluten-free diet in Canadian adults with celiac disease.

BACKGROUND Celiac disease can present with mild or nongastrointestinal symptoms, and may escape timely recognition. The treatment of celiac disease involves a gluten-free diet, which is complex and challenging. OBJECTIVE To evaluate clinical features and symptom recovery on a gluten-free diet in a Canadian adult celiac population. METHODS All adult members (n=10,693) of the two national celiac support organizations, the Canadian Celiac Association and Fondation québécoise de la maladie coeliaque, were surveyed using a questionnaire. RESULTS A total of 5912 individuals (≥18 years of age) with biopsy-confirmed celiac disease and⁄or dermatitis herpetiformis completed the survey. The female to male ratio was 3:1, and mean (± SD) age at diagnosis was 45.2 ± 16.4 years. Mean time to diagnosis after onset of symptoms was 12.0 ± 14.4 years. Abdominal pain and bloating (84.9%), extreme weakness⁄tiredness (74.2%), diarrhea (71.7%) and anemia (67.8%) were the most commonly reported symptoms at the time of diagnosis. Many respondents continued to experience symptoms after being on a gluten-free diet for >5 years. Sex differences were reported in clinical features before diagnosis, recovery after being on gluten-free diet and perceived quality of life, with women experiencing more difficulties than men. CONCLUSIONS Delays in diagnosis of celiac disease in Canada remain unacceptably long despite wider availability of serological screening tests. Many patients report continuing symptoms despite adhering to a gluten-free diet for >5 years, with women experiencing more symptoms and a lower recovery rate than men. Awareness of celiac disease needs improvement, and follow-up with a physician and a dietitian is essential for all patients with celiac disease.

Development of ELISAs for detecting domoic acid, okadaic acid, and saxitoxin and their applicability for the detection of marine toxins in samples collected in Belgium

Okadaic acid, a diarrhetic shellfish poison, domoic acid, an amnesic shellfish poison, and saxitoxin, a paralytic shellfish poison, are three of the best-known marine biotoxins. The mouse bioassay is the method most widely used to detect many of these toxins in shellfish samples, but animal welfare concerns have prompted researchers to seek alternative methods of detection. In this study, three direct competitive enzyme-linked immunosorbent assays (ELISAs), each based on antibodies raised in rabbits against a conjugate of the analyte of interest, were developed for marine biotoxin detection in mussel, oyster, and scallop. One assay was for okadaic acid, one for saxitoxin, and one for domoic acid usually detected and quantified by high-performance liquid chromatography-ultraviolet light (HPLC-UV). All three compounds and a number of related toxins were extracted quickly and simply from the shellfish matrices with a 9 : 1 mixture of ethanol and water before analysis. The detection capabilities (CCβ values) of the developed ELISAs were 150 µg kg−1 for okadaic acid, 50 µg kg−1 for domoic acid, and 5 µg kg−1 or less for saxitoxin. The assays proved satisfactory when used over a 4-month period for the analysis of 110 real samples collected in Belgium.

Demographic predictors of peanut, tree nut, fish, shellfish, and sesame allergy in Canada.

Background. Studies suggest that the rising prevalence of food allergy during recent decades may have stabilized. Although genetics undoubtedly contribute to the emergence of food allergy, it is likely that other factors play a crucial role in mediating such short-term changes. Objective. To identify potential demographic predictors of food allergies. Methods. We performed a cross-Canada, random telephone survey. Criteria for food allergy were self-report of convincing symptoms and/or physician diagnosis of allergy. Multivariate logistic regressions were used to assess potential determinants. Results. Of 10,596 households surveyed in 2008/2009, 3666 responded, representing 9667 individuals. Peanut, tree nut, and sesame allergy were more common in children (odds ratio (OR) 2.24 (95% CI, 1.40, 3.59), 1.73 (95% CI, 1.11, 2.68), and 5.63 (95% CI, 1.39, 22.87), resp.) while fish and shellfish allergy were less common in children (OR 0.17 (95% CI, 0.04, 0.72) and 0.29 (95% CI, 0.14, 0.61)). Tree nut and shellfish allergy were less common in males (OR 0.55 (95% CI, 0.36, 0.83) and 0.63 (95% CI, 0.43, 0.91)). Shellfish allergy was more common in urban settings (OR 1.55 (95% CI, 1.04, 2.31)). There was a trend for most food allergies to be more prevalent in the more educated (tree nut OR 1.90 (95% CI, 1.18, 3.04)) and less prevalent in immigrants (shellfish OR 0.49 (95% CI, 0.26, 0.95)), but wide CIs preclude definitive conclusions for most foods. Conclusions. Our results reveal that in addition to age and sex, place of residence, socioeconomic status, and birth place may influence the development of food allergy.