To develop and test a method to assess adherence to a rotary diversified diet (RDD), a treatment for environmental illness, which is a putative disorder characterized by multiple sensitivities to foods, chemicals, or inhalants. The RDD requires the elimination of prohibited foods and rotation of remaining nonprohibited foods and their "food families" within a 4- to 7-day cycle. The regimen has yet to be validated to the satisfaction of the scientific community.
Details of the 2 components of the RDD prescription, elimination and rotation, were documented, and a food record method of assessing adherence was developed. Adherence to the RDD was then assessed in a cohort of women who were enrolled in a larger prospective study. Test-retest reliability of the adherence assessment method was determined by calculating ratings twice on the same set of patient food records, with 1 week between trials.
All patients were contacted through a private environmental medicine clinic in Toronto, Canada. Eight patients provided the food records needed for development of the method; adherence was then assessed in 22 women aged 25 to 67 years.
Means, standard deviations, and 95% confidence intervals for adherence ratings were calculated. The reliability of the adherence assessment method was determined by calculating Pearson correlation coefficients for adherence ratings from each trial. A paired t test was also used to determine if the mean differences in ratings between trials were significant.
Patients experienced difficulties following both components of the RDD: 37% to 44% of foods consumed were either prohibited or allowed, but were consumed on the incorrect day. The adherence assessment method was found to have high levels of reliability.
The adherence assessment method can be used in future evaluations of the RDD, although further testing of the method is recommended. Increased involvement of dietitians with patients diagnosed with environmental illness is recommended.
The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein. Therefore, decision trees for evaluation of the risk have been developed, the latest being proposed by WHO/FAO early in 2001. Proteins developed using modern biotechnology and derived from fish are being considered for use in food and other applications, and since allergy to fish is well established, a potential risk from such proteins to susceptible human beings exists. The overall aim of the study was to investigate the potential allergenicity of an Ice Structuring Protein (ISP) originating from an arctic fish (the ocean pout, Macrozoarces americanus) using the newly developed decision tree proposed by FAO/WHO. The methods used were those proposed by FAO/WHO including amino acid sequence analysis for sequence similarity to known allergens, methods for assessing degradability under standardised conditions, assays for detection of specific IgE against the protein (Maxisorb RAST) and histamine release from human basophils. In the present paper we describe the serum screening phase of the study and discuss the overall application of the decision tree to the assessment of the potential allergenicity of ISP Type III. In an accompanying paper [Food Chem. Toxicol. 40 (2002) 965], we detail the specific methodology used for the sequence analysis and assessment of resistance to pepsin-catalysed proteolysis of this protein. The ISP showed no sequence similarity to known allergens nor was it stable to proteolytic degradation using standardised methods. Using sera from 20 patients with a well-documented clinical history of fish allergy, positive in skin prick tests to ocean pout, eel pout and eel were used, positive IgE-binding in vitro to extracts of the same fish was confirmed. The sera also elicited histamine release in vitro in the presence of the same extracts. The ISP was negative in all cases in the same experiments. Using the proposed decision tree, we demonstrated the safety of the ISP to patients already sensitised to fish, as well as to individuals potentially susceptible to producing IgE responses to proteins. Furthermore, the practicability of the new decision tree was confirmed.
AIMS: To investigate the effect of breast feeding on allergic disease in infants up to 2 years of age. METHODS: A birth cohort of 4089 infants was followed prospectively in Stockholm, Sweden. Information about various exposures was obtained by parental questionnaires when the infants were 2 months old, and about allergic symptoms and feeding at 1 and 2 years of age. Duration of exclusive and partial breast feeding was assessed separately. Symptom related definitions of various allergic diseases were used. Odds ratios (OR) and 95% confidence intervals (CI) were estimated in a multiple logistic regression model. Adjustments were made for potential confounders. RESULTS: Children exclusively breast fed during four months or more exhibited less asthma (7.7% v 12%, OR(adj) = 0.7, 95% CI 0.5 to 0.8), less atopic dermatitis (24% v 27%, OR(adj) = 0.8, 95% CI 0.7 to 1.0), and less suspected allergic rhinitis (6.5% v 9%, OR(adj) = 0.7, 95% CI 0.5 to 1.0) by 2 years of age. There was a significant risk reduction for asthma related to partial breast feeding during six months or more (OR(adj) = 0.7, 95% CI 0.5 to 0.9). Three or more of five possible allergic disorders-asthma, suspected allergic rhinitis, atopic dermatitis, food allergy related symptoms, and suspected allergic respiratory symptoms after exposure to pets or pollen-were found in 6.5% of the children. Exclusive breast feeding prevented children from having multiple allergic disease (OR(adj) = 0.7, 95% CI 0.5 to 0.9) during the first two years of life. CONCLUSION: Exclusive breast feeding seems to have a preventive effect on the early development of allergic disease-that is, asthma, atopic dermatitis, and suspected allergic rhinitis, up to 2 years of age. This protective effect was also evident for multiple allergic disease.
There have been major developments this past year in the Marine and Freshwater Toxins topic area (formerly Phycotoxins). These include AOAC approval and inauguration of a new AOAC Presidential Task Force on Marine and Freshwater Toxins to accelerate methods validation, and the appointment of several new Topic Advisors. A joint FAO/IOC/WHO group addressing biotoxins in molluscan bivalves is also relevant to this report and to the new Task Force. The AOAC Presidential Task Force on Marine and Freshwater Toxins is an international group that, in late November 2004, consisted of 90 world experts and stakeholders. Chaired by this General Referee, the group establishes methods priorities based on analytical methods criteria, determines fitness for purpose, identifies and reviews available methodologies, recommends methodologies for validation, and identifies complementary analytical tools. Once appropriate analytical methodology has been identified or developed, the Task Force is able to identify financial and technical resources necessary to validate the methods. The first two formal meetings of the Task Force were held in Bethesda, MD, on May 19, 2004 and in St. Louis, MO, on September 22, 2004. These meetings were held in conjunction with the XI International IUPAC Symposium on Mycotoxins and Phycotoxins and the 118th AOAC INTERNATIONAL Annual Meeting and Exposition, respectively. The Bethesda meeting served to introduce members of the group to the AOAC Community/Task Force model and to discuss objectives, concerns, general workings, and communications. The meeting concluded on an encouraging note, with a commitment from AOAC to help provide financial resources for the review of nonproprietary methods deemed high priority by the Task Force. This development was seen as an important step toward reaching methods validation objectives. The terms of reference for the Task Force were approved by the AOAC Board of Directors in late June, 2004. They described the Task Force membership as composed of voting and nonvoting members, with the voting members consisting of 13 members (12 plus the Chair). Voting members comprise of a balance of government regulators, academics, and industry members. No single agency has more than 2 voting members. Task Force members serve as experts in the field and agree to identify other experts; recommend individuals who can serve on the Task Force and as Chair; develop and prioritize a list of marine and freshwater toxins that need validated methods; assist in identifying existing methods for validation through AOAC validation programs; and recommend to the AOAC INTERNATIONAL Board of Directors policies and procedures necessary to accomplish the mission of the Task Force. They endeavor to actively support the work of the Task Force through garnering of sources of funding (except where prohibited by employer); identifying potential participating laboratories, sample identification and acquisition; and increasing program awareness among stakeholders. They assist AOAC in the identification of study directors and in the development of quality measurement tools by participating in the validation of methods and by identifying venues for members of the Task Group or the community to gather and assist with meeting content. Prior to the September 2004, AOAC Annual Meeting, the Task Force approved a set of Analytical Methods Selection Criteria, which are critical to the mission of the Task Force. They can be found, along with the Terms of Reference, roster of members, and other information, on the Task Force Web site at http://www.aoac.org/marine toxins/task_force.htm. The September 22, 2004 Task Force meeting in St. Louis included discussion of 2 interlaboratory studies, a proprietary kit for domoic acid by enzyme-linked immunosorbent assay (ELISA; Biosense Labs AS, Bergen, Norway) and also a nonproprietary liquid chromatography (LC) method for paralytic shellfish poisoning (PSP) toxins by precolumn oxidation (James F. Lawrence, Health Canada). These 2 methods were recommended by the Task Force for review by AOAC in September 2004. The group also discussed future priority directions, aspects of interlaboratory studies and official methods of analysis, other methods validation issues, future meetings, and funding. In addition to the Task Force meeting, 2 subgroup meetings were held. One subgroup addressed strategies to replace the mouse bioassay for brevetoxins with alternative modern methods based on ELISA or LC/mass spectrometry (MS). Brevetoxin metabolites, toxicity issues, and extraction conditions as well as future field studies were addressed in detail. The receptor binding assay (RBA)/saxitoxins subgroup addressed several aspects of the methodology, radiolabeled saxitoxin, and comparisons of mouse bioassay and RBA response. Both subgroups were productive and were seen as very useful by the participants. Task Force attendees generally agreed that subgroups are the most effective means of progressing towards validation of new methods and of ensuring thorough discussions of methods under consideration. By the time of their next meeting (April 2005) at the "Marine and Freshwater Toxins Analysis: 1st Joint Symposium and AOAC Task Force Meeting" in Baiona, Spain, the Task Force will have several well developed new subgroups in the areas of okadaic acid and dinophysis toxins, yessotoxins, domoic acids, and ciguatoxins. Some of the subgroups will hold face-to-face meetings in Spain and others will meet at future symposia or joint meetings. It is likely that training sessions will be associated with multiple Task Force meetings planned for 2005. Details on these meetings can be found on the Task Force Web site. Although the Task Force has experienced rapid growth, the addition of new members to the group, especially industry and government stakeholders, is encouraged. Task Force member Michael Quilliam, NRC Canada, provided the information given below on a joint CODEX group of special relevance to the new Task Force. This group met in late September 2004. For more information, see http://www.who.int/foodsafety/chem/meetings/biotoxin/en/.
AIM: The aim of the current study was to retrospectively examine introduction of food during the first year in a representative sample of Swedish children. A secondary aim was to study how parents with history of atopy introduced food to their infants. METHODS: Data derive from 467 infants who visited child health centres in three different counties in Sweden for health check-up at 12 mo of age. The parents were asked to fill in a questionnaire about breastfeeding and/or formula feeding, time of introduction of weaning food focusing on cow's milk, follow-on formula, porridge, fish and egg. Questions regarding hypersensitivity in the family, peanut consumption of mother as well as in the child, and questions about number of siblings, ethnic background and parental education were included. RESULTS: Compliance with suggested introduction of gluten-containing food was low; as many as 45% had avoided gluten until 6 mo of age, instead of introducing gluten between 4 and 6 mo. Only 33% of parents with stated family hypersensitivity avoided giving their child fish and 23% avoided egg during the first year, even though this recommendation was present at the time of the study. Almost 50% of all mothers had avoided peanuts during pregnancy even though there was no such advice. The avoidance of peanut was not connected to hypersensitivity in the family. CONCLUSION: These results suggest that time of introduction of gluten was not in accordance with the current recommendation. The results imply that there is a need to follow up if and how this feeding information is distributed to parents with infants and also to sharpen the information to the right target groups, otherwise implementation of preventive strategies will be less useful.
Tryptophan was isolated from rat feces as an active compound against ovalbumin permeation in an in vitro Caco-2 cell model. Tryptophan dose-dependently inhibited ovalbumin permeation with accompanying increase in transepithelial electric resistance, and its inhibitory activity reached a plateau at 10 mM. Brown Norway rats were sensitized by intragastric administration of ovalbumin together with or without tryptophan. Antibody levels specific to ovalbumin in the sera and proliferative responses of spleen mononuclear cells to ovalbumin were significantly lower in rats administered ovalbumin plus tryptophan than those administered ovalbumin alone. These results suggest that tryptophan suppresses oral sensitization to ovalbumin, probably via suppression of ovalbumin absorption from the intestinal tract.
An overview is presented of the activities of Health Canada and the Canadian Food Inspection Agency (CFIA) in the area of food allergens. Since the 1990s, changes were made in the Food and Drug Regulations in order to better protect allergic consumers by imposing labeling requirements to clearly identify sources of priority food allergens in prepackaged foods. Policies of application as well as risk management strategies are discussed with some statistics on allergen-related food recalls in Canada for the years 1997--2001. Health Canada's allergen method development program is a pioneering research initiative that was developed in the early 1990s in support of the changing Canadian regulatory environment. The objectives and some of the accomplishments of this program are presented. The development of the Canadian Compendium of Allergen Methodologies under a Web-based application to compile data on evaluated allergen detection methods will provide further support to compliance activities nationally, as well as to the international analytical community in both government and the food industry. Some emerging techniques for the confirmation of results generated by enzyme-linked immunosorbent assays are also discussed.
The rotary diversified diet, which involves food elimination and rotation of remaining allowed foods, is commonly used in the management of environmental illness. No studies have considered patient adherence while evaluating the effectiveness of the diet in controlling symptoms.
The study examined the severity of patients' perceived symptoms and dietary adherence during treatment with a rotary diversified diet.
A prospective and exploratory study using purposive sampling and the following data collection methods: personal interviews, symptom severity questionnaires, and food records to assess dietary adherence.
Private clinic of a Toronto, Ontario physician specializing in environmental medicine.
Twenty-five female residents of Toronto, Ontario (aged 25-67 years) diagnosed with environmental illness.
Patients were treated with a rotary diversified diet for 16 weeks.
Symptom severity and dietary adherence were assessed after 4, 10, and 16 weeks of treatment. Adherence was assessed by comparing food records to the diet prescription.
At 16 weeks, patients reported a 50% decline in symptom severity for 5 of the 6 symptom categories assessed and for all categories combined. Those with closer elimination and rotation adherence reported a greater decline in gastrointestinal symptoms at 4 and 10 weeks of treatment, respectively. Improvement in total symptom severity was associated with closer rotation adherence at 10 weeks. Patients experienced difficulties in adhering to the diet.
Results suggest that the diet, if followed, is beneficial, especially in improving gastrointestinal symptoms. Further evaluation of its effectiveness is limited by its complexity and the nature of environmental illness. Because the diet is difficult to follow over time, patients require extensive nutritional counseling and support.