Food Safety and Cross-Contamination of Gluten-Free Products: A Narrative Review

A gluten-free diet (GFD) is currently the only effective treatment for celiac disease (CD); an individual’s daily intake of gluten should not exceed 10 mg. However, it is difficult to maintain a strict oral diet for life and at least one-third of patients with CD are exposed to gluten, despite their best efforts at dietary modifications. It has been demonstrated that both natural and certified gluten-free foods can be heavily contaminated with gluten well above the commonly accepted threshold of 20 mg/kg. Moreover, meals from food services such as restaurants, workplaces, and schools remain a significant risk for inadvertent gluten exposure. Other possible sources of gluten are non-certified oat products, numerous composite foods, medications, and cosmetics that unexpectedly contain “hidden” vital gluten, a proteinaceous by-product of wheat starch production. A number of immunochemical assays are commercially available worldwide to detect gluten. Each method has specific features, such as format, sample extraction buffers, extraction time and temperature, characteristics of the antibodies, recognition epitope, and the reference material used for calibration. Due to these differences and a lack of official reference material, the results of gluten quantitation may deviate systematically. In conclusion, incorrect gluten quantitation, improper product labeling, and poor consumer awareness, which results in the inadvertent intake of relatively high amounts of gluten, can be factors that compromise the health of patients with CD.     

The Gluten-Free Diet: Testing Alternative Cereals Tolerated by Celiac Patients

A strict gluten-free diet (GFD) is the only currently available therapeutic treatment for patients with celiac disease, an autoimmune disorder of the small intestine associated with a permanent intolerance to gluten proteins. The complete elimination of gluten proteins contained in cereals from the diet is the key to celiac disease management. However, this generates numerous social and economic repercussions due to the ubiquity of gluten in foods. The research presented in this review focuses on the current status of alternative cereals and pseudocereals and their derivatives obtained by natural selection, breeding programs and transgenic or enzymatic technology, potential tolerated by celiac people. Finally, we describe several strategies for detoxification of dietary gluten. These included enzymatic cleavage of gliadin fragment by Prolyl endopeptidases (PEPs) from different organisms, degradation of toxic peptides by germinating cereal enzymes and transamidation of cereal flours. This information can be used to search for and develop cereals with the baking and nutritional qualities of toxic cereals, but which do not exacerbate this condition.     

Wheat Starch, Gliadin, and the Gluten-free Diet

Individuals with celiac disease generally are advised to follow a lifelong gluten-free diet and avoid consumption of the prolamins gliadin (wheat), secalin (rye), and hordein (barley). Although the designation of the diet as gluten free may imply that the diet contains zero gluten, this is not necessarily true. In some countries (eg, United States, Canada), the gluten-free diet is completely devoid of gluten and is based on foods such as rice and corn that are naturally gluten free. In others (eg, Scandinavia, United Kingdom), the gluten-free diet may include foods such as wheat starch that have been rendered gluten free but nonetheless contain small amounts of toxic prolamins. The discrepancy in the use of foods rendered gluten free exists because the amount of toxic prolamins that individuals with celiac disease may consume without damaging the mucosa of the small intestine is unknown. Minimal research has been conducted on the toxicity of foods rendered gluten free, and there are no definitive data about whether the small amount of prolamin found in these products is safe to consume. Nonetheless, the Codex Alimentarius Standard for gluten-free foods allows a certain amount of prolamin in foods designated gluten free, and these products have been used in many countries for several decades. Well-designed, scientifically sound studies are needed to help determine the amount of toxic prolamins, if any, that may be safely consumed by individuals with celiac disease. Until this research is conducted, dietitians in the United States should continue to advise their patients against the use of wheat starch and other foods rendered gluten free. J Am Diet Assoc. 2001; 101:1456-1459.     

Gluten Contamination of Grains, Seeds, and Flours in the United States: A Pilot Study

Under the Food Allergen and Consumer Protection Act, the Food and Drug Administration (FDA) must issue a rule for the voluntary labeling of food as gluten-free. In the proposed rule, many single-ingredient foods, such as millet, are considered inherently free of gluten. Inherently gluten-free grains will be considered misbranded if they carry a gluten-free label and do not also state that all foods of the same type are gluten-free (eg, “all millet is gluten free”). Twenty-two inherently gluten-free grains, seeds, and flours not labeled gluten-free were purchased in June 2009 and sent unopened to a company who specializes in gluten analysis. All samples were homogenized and tested in duplicate using the Ridascreen Gliadin sandwich R5 enzyme-linked immunosorbent assay with cocktail extraction. Thirteen of 22 (59%) samples contained less than the limit of quantification of 5 parts per million (ppm) for gluten. Nine of 22 (41%) samples contained more than the limit of quantification, with mean gluten levels ranging from 8.5 to 2,925.0 ppm. Seven of 22 samples (32%) contained mean gluten levels ≥20 ppm and would not be considered gluten-free under the proposed FDA rule for gluten-free labeling. Gluten contamination of inherently gluten-free grains, seeds, and flours not labeled gluten-free is a legitimate concern. The FDA may want to modify their proposed rule for labeling of food as gluten-free, removing the requirement that gluten-free manufacturers of inherently gluten-free grains, seeds, and flours must state on product labels that all foods of that type are gluten-free.     

Quantification of Accidental Gluten Contamination in the Diet of Children with Treated Celiac Disease

A strict gluten-free diet is extremely difficult to maintain. Protracted ingestion of gluten traces (>10 mg/day) is sufficient to cause significant damage in the architecture of the small intestinal mucosa in patients on treatment for celiac disease. The aim of this study was to directly measure the level of contaminating gluten in the daily diet of celiac children following a gluten-free diet. From April 2019 to December 2019, celiac disease children (2–18 years old) on a gluten-free diet for ≥6 months were offered to participate in this prospective-observational study. Patients and their caregivers were invited to provide a representative portion (about 10 g) of all meals consumed during a 24-h period. Participants were requested to weigh all ingested food and report items in a 24-h food diary. The gluten content was quantified by the R5 sandwich enzyme-linked immunosorbent assay method. Sixty-nine children completed the protocol. Overall, 12/448 (2.7%) food samples contained detectable amounts of gluten; of them, 11 contained 5–20 ppm and 1 >20 ppm. The 12 contaminated food samples belonged to 5/69 enrolled patients. In these 5 children, the daily gluten intake was well below the safety threshold of 10 mg/day. The present findings suggest that in a country characterized by high celiac disease awareness, the daily unintended exposure to gluten of treated celiac children on regular follow-up is very low; reassuringly, the presence of gluten traces did not lead to exceed the tolerable threshold of 10 mg/day of gluten intake in the gluten-free diet.     

The effect of substituting alternative grains in the diet on the nutritional profile of the gluten-free diet

Background:  The only treatment for coeliac disease is lifelong adherence to a gluten-free diet. Several studies have reported nutritional deficiencies in individuals on a gluten-free diet. The present study aimed to determine whether the nutritional profile of gluten-free diet could be improved through the use of alternative grains.
Methods:  A retrospective review of diet history records by a celiac specialist dietitian were used to establish a 'standard' gluten-free dietary pattern. An 'alternative' gluten-free dietary pattern was developed that substituted naturally gluten-free grains or gluten-free products made from 'alternative' flours (oats, high fibre gluten-free bread and quinoa) in the standard pattern. A paired t- test was performed to identify statistical significance between the 'alternative' and standard gluten-free dietary pattern.
Results:  Analysis of standard pattern indicated that 38% of meals and snacks contained no grain or starch choice. Of those meals that contained a grain or starch component, rice was the grain chosen 44% of the time. The inclusion of alternative grains or grain products provided a higher nutrient profile compared to the standard gluten-free dietary pattern ( P  = 0.002). Several nutrients; protein (20.6 g versus 11 g), iron (18.4 mg versus 1.4 mg), calcium (182 mg versus 0 mg) and fibre (12.7 g versus 5 g) were significantly increased by changing the grain or starch component in the dietary pattern. The B vitamin content (riboflavin, niacin and folate) was improved, although this was not statistically significant ( P  = 0.125).
Discussion:  The inclusion of alternative grain-based products increased the nutrient profile of the gluten-free dietary pattern significantly.     

The gluten-free diet: safety and nutritional quality

The prevalence of celiac disease (CD), an autoimmune enteropathy, characterized by chronic inflammation of the intestinal mucosa, atrophy of intestinal villi and several clinical manifestations has increased in recent years. Subjects affected by CD cannot tolerate gluten protein, a mixture of storage proteins contained in several cereals (wheat, rye, barley and derivatives). Gluten free-diet remains the cornerstone treatment for celiac patients. Therefore the absence of gluten in natural and processed foods represents a key aspect of food safety of the gluten-free diet. A promising area is the use of minor or pseudo-cereals such as amaranth, buckwheat, quinoa, sorghum and teff. The paper is focused on the new definition of gluten-free products in food label, the nutritional properties of the gluten-free cereals and their use to prevent nutritional deficiencies of celiac subjects.     

A milligram of gluten a day keeps the mucosal recovery away: a case report

In recent years it has been suggested that patients with celiac disease can be adequately followed up on the basis of merely clinical and serological response to a gluten-free diet. Thus, a duodenal biopsy some months after commencement of a gluten-free diet would no longer be necessary. We report here the case of a celiac patient in whom the ingestion of a milligram of gluten every day for 2 years prevented histological recovery in spite of satisfactory clinical and serological response. The literature regarding the minimal amount of gluten that could be harmless to celiac patients is reviewed.     

Celiac disease: understanding the gluten-free diet

Purpose

The only effective and safe treatment of celiac disease (CD) continues being strict exclusion of gluten for life, the so-called gluten-free diet (GFD). Although this treatment is highly successful, following strict GFD poses difficulties to patients in family, social and working contexts, deteriorating his/her quality of life. We aimed to review main characteristics of GFD with special emphasis on factors that may interfere with adherence to it.

Methods

We conducted a search of various databases, such as PubMed, Google Scholar, Embase, and Scielo, with focus on key words such as “gluten-free diet”, “celiac disease”, “gluten” and “gluten-free diet adherence”. Available literature has not reached definitive conclusions on the exact amount of gluten that is harmless to celiac patients, although international agreements establish cutoff points for gluten-free products and advise the use of clinical assessment to tailor the diet according to individual needs. Following GFD must include eliminating gluten as ingredient as well as hidden component and potential cross contamination in foods. There are numerous grains to substitute wheat but composition of most gluten-free products tends to include only a small number of them, especially rice. The diet must be not only free of gluten but also healthy to avoid nutrient, vitamins and minerals deficiencies or excess. Overweight/obesity frequency has increased among celiac patients so weight gain deserves attention during follow up. Nutritional education by a trained nutritionist is of great relevance to achieve long-term satisfactory health status and good compliance.

Conclusions

A balanced GFD should be based on a combination of naturally gluten-free foods and certified processed gluten-free products. How to measure and improve adherence to GFD is still controversial and deserves further study.

     

Addition of gluten values to a food and nutrient database

Gluten is a protein found in wheat, rye, barley, and their crossbred varieties and derivatives. It is responsible for triggering hypersensitivity reactions in people with celiac disease, and research is underway to determine whether it may contribute to other health outcomes. The objective of the study was to add gluten values to the University of Minnesota Nutrition Coordinating Center (NCC) Food and Nutrient Database so that researchers conducting studies related to gluten may assess intake of this food component. Gluten values were assigned to foods in the NCC Food and Nutrient Database using imputation procedures based on two assumptions. The first is that foods that do not include any wheat, rye, or barley grain ingredients or their derivatives are presumed to contain 0 grams of gluten. Thus, foods such as fruits, vegetables, and vegetable oils were assigned gluten values of 0 grams. The second is that a specified fraction of protein found in wheat, rye, barley and their crossbred varieties and derivatives (0.75) is presumed to be gluten. A factor of 0.75 was selected based on findings from studies in which chemical analysis of some gluten - containing grains and their derivatives were carried out to estimate the percentage of gluten. It is important to note that gluten values in the NCC Database may not be appropriate for use in determining whether a food or diet is gluten-free because foods with “zero” values may not meet the FDA definition of gluten-free (<20 parts per million of gluten). However, the values may be useful in determining whether a food or diet is low / limited or high in gluten.     

Self-Reported Prevalence of Symptomatic Adverse Reactions to Gluten and Adherence to Gluten-Free Diet in an Adult Mexican Population

The prevalence of symptomatic adverse reactions to gluten and adherence to gluten-free diet in Latin American countries is unknown. These measurements are strongly linked to gluten-related disorders. This work aimed to estimate the prevalence of adverse reactions to oral gluten and the adherence to gluten-free diet in the adult Mexican population. To reach this aim, a self-administered questionnaire was designed and tested for clarity/comprehension and reproducibility. Then, a self-administered questionnaire-based cross-sectional study was conducted in the Mexican population. The estimated prevalence rates were (95% CI): 11.9% (9.9–13.5) and 7.8 (6.4–9.4) for adverse and recurrent adverse reactions to gluten respectively; adherence to gluten-free diet 3.7% (2.7–4.8), wheat allergy 0.72% (0.38–1.37); celiac disease 0.08% (0.01–0.45), and NCGS 0.97% (0.55–1.68). Estimated pooled prevalence of self-reported physician-diagnosis of gluten-related disorders was 0.88% (0.49–1.5), and 93.3% respondents reported adherence to gluten-free diet without a physician-diagnosis of gluten-related disorders. Symptom comparisons between those who reported recurrent adverse reactions to gluten and other foods showed statistically significant differences for bloating, constipation, and tiredness (p < 0.05). Gluten-related disorders may be underdiagnosed in the Mexican population and most people adhering to a gluten-free diet are doing it without proper diagnostic work-up of these disorders, and probably without medical/dietician advice.     

Hydrocolloids in gluten-free breads: a review

Bread is a traditional food generally prepared from wheat flour. The main wheat component responsible for bread quality is gluten, which is an essential structure-binding protein. Although important, this protein can cause health problems in predisposed individuals, and is avoided in the diet of celiac disease patients. As diagnosis methods are improved, revealing the high incidence of gluten-intolerance in the western world, the demand for novel, nutritious and high-quality gluten-free foods also ascends. However, for the production of gluten-free breads the absence of gluten is critical and challenging in regards to the bread structure. Various gluten-free formulations have applied hydrocolloids to mimic the viscoelastic properties of gluten. They comprise a number of water-soluble polysaccharides with varied chemical structures providing a range of functional properties that make them suitable to this application. This paper reviews some actual facts about celiac disease and focuses on the reported applications of hydrocolloids in gluten-free breads.     

Evaluation of gluten in gluten-free-labeled foods and assessment of exposure level to gluten among celiac patients in Lebanon

The aim of the study was to evaluate gluten contamination in all the gluten-free (GF)-labeled food products sold in Lebanon. Over a 2-year period, a total of 173 food samples collected from 135 brand names were analyzed. Gluten contamination was detected in 33 of 173 (19%) samples, and its content ranged between 2.5 and >80?mg?kg^?1. In 10 of the 173 samples (6%), the quantity of gluten exceeded the upper limit of 20?mg?kg^?1. Out of the 10 contaminated products, eight (80%) were locally manufactured. Among these 10 products, eight (80%) were wheat-starch-based foods. Of the 40 brand names tested twice in 2014 and 2015, 15 (38%) showed significantly (p?相似文献   

Wait-and-See Approach or Gluten-Free Diet Administration—The Rational Management of Potential Coeliac Disease

Potential celiac disease (PCD) is a heterogeneous disease; only some patients develop full celiac disease (CD), characterised by advanced atrophic changes in the small intestine. Few accurate prognostic factors exist for the progression of PCD; therefore, therapeutic decisions should be made on an individual basis in each case. Patients with clinical gastroenterological or parenteral symptoms often benefit from a gluten-free diet, and those left on a diet containing gluten should receive clinical, serological and histopathological supervision.     

The Gluten-Free Diet for Celiac Disease and Beyond

The gluten-free diet (GFD) has gained popularity beyond its main medical indication as the treatment for gluten-induced immune-mediated disorders such as celiac disease (CD), dermatitis herpetiformis, gluten ataxia, wheat allergy, and non-celiac gluten sensitivity. However, the diet carries some disadvantages such as elevated costs, nutritional deficiencies, and social and psychological barriers. The present work aims to review indications, proven benefits, and adverse events of a gluten-free diet. Close follow-up with patients following the diet is recommended. More data is needed to assess the effectiveness of the diet in managing mental and cognitive disorders and to establish a connection between the brain and gluten.     

Gluten-Free Diet in Children: An Approach to a Nutritionally Adequate and Balanced Diet

Gluten-free diet (GFD) is the cornerstone treatment for celiac disease (CD). GFD implies a strict and lifelong elimination from the diet of gluten, the storage protein found in wheat, barley, rye and hybrids of these grains, such as kamut and triticale. The absence of gluten in natural and processed foods, despite being the key aspect of GFD, may lead to nutritional consequences, such as deficits and imbalances. The nutritional adequacy of GFD is particularly important in children, this the age being of maximal energy and nutrient requirements for growth, development and activity. In recent years, attention has focused on the nutritional quality of gluten-free products (GFPs) available in the market. It is well recognized that GFPs are considered of lower quality and poorer nutritional value compared to the gluten-containing counterparts. The present review focuses on the nutritional adequacy of GFD at the pediatric age, with the aim being to increase awareness of the potential complications associated with this diet, to identify strategies in order to avoid them and to promote a healthier diet and lifestyle in children with CD.     

Knowledge of Medical Students and Medical Professionals Regarding Nutritional Deficiencies in Patients with Celiac Disease

A gluten-free diet provides relief from symptoms for patients with celiac disease, although there is still a risk of nutritional deficiencies. These patients can potentially consume an excessive amount of fat and insufficient amounts of fiber, iron, vitamin D, and calcium. This study aimed to assess the knowledge of medical students and healthcare professionals in Poland regarding nutritional deficiencies and the prevention of such deficiencies in patients with celiac disease who are on a gluten-free diet. Of the 430 survey participants, 46% did not realize the risk of nutritional deficiencies in patients with celiac disease. The knowledge of the participants was lowest regarding the risk of being overweight or obese. Among the healthcare professionals, an acceptable level of correct answers was provided by only 37% of individuals and was highest for the dietitians’ group. Our results demonstrate the need to improve the education of healthcare professionals concerning nutrition in patients with celiac disease.     

Psyllium as a Substitute for Gluten in Pastas

The aim of the present study was to evaluate the effect of replacing gluten in favor of psyllium in pasta’s characteristics. This study takes an exploratory and quantitative approach and was sub-divided into four steps: selection and development of recipes and chemical and sensorial analysis. Modified samples of the pasta presented 100.0% of acceptance for individuals with celiac disease and up to 94.0% for individuals without celiac disease. The most affected characteristics were odor and texture. In terms of chemical composition, reduction of energy value was 26.5% and of proportional fat was 85.4% before being cooked. Substituting wheat flour for a mixture of gluten-free flours with psyllium did not alter preference or acceptability of modified products in relation to standardized ones and amplified feeding options for celiac disease patients. Thus, there were no damages in sensorial characteristics of these products.     

Amaranth Pasta in Mexico: A Celiac Overview

Amaranth is one of the most representative crops in Mexico and could represent an alternative for consumers with celiac disease. Since it possesses no gluten, it can be included in the production of non-conventional starchy foods. This work was focused on the evaluation of process conditions and adequacy of a gluten-free lasagna. Four amaranth formulations containing corn and tapioca starches at different concentrations were analyzed. Ready-to-cook samples were obtained after drying (80°C for 45 min). Pasta containing 8% corn starch reported the highest stability during blending (1.5 min) and a firmness value of 16.060 kg. This formulation was subjected to sensory analysis by 10 celiac consumers. Overall acceptability received an average score of 4.7 on a 9-point hedonic scale with a possible intention of buying.     

Evaluation of visual and taste preferences of some gluten-free commercial products in a group of celiac children

The purpose of this study was to investigate the visual and taste liking of three commercial gluten-free (GF) foods in a group of celiac children. Thirty celiac children, with diagnosis of celiac disease from more than 2 years, were recruited and 28 (21 females and 7 males, mean age 8.7 years) completed the study. Subjects performed individually six sensory tests, two for each product in different days separated by a week. In the test day, children had to evaluate the liking of the same type of product but of different four brands, before and after tasting them with a 5-point facial rating scale. Overall, the results showed that the majority of children appreciated more the appearance than the taste of all the GF products analysed. The present study provides the first and useful indications on the hedonic perceptions of celiac children about some commercial GF products.