Prevalence of gluten-free diet adherence among individuals without celiac disease in the USA: results from the Continuous National Health and Nutrition Examination Survey 2009-2010.

Abstract

"OBJECTIVES:

Clinical inference suggests the prevalence of non-celiac gluten sensitivity is substantially higher than that of celiac disease in the USA. Unfortunately, there are currently no data supporting these claims. The authors analyzed nationally representative data to estimate the prevalence of adherence to agluten-free diet among participants without celiac disease and also to characterize the demographics and general health status of these participants.

STUDY DESIGN AND SETTING:

The Continuous National Health and Nutrition Examination Survey (NHANES) 2009-2010 enrolled 7762 individuals representing the civilian, non-institutionalized, US population free of celiac disease. Participants responded to interviewer administered questionnaires regarding current adherence to a gluten-free diet. Prevalence estimates were computed using SAS survey procedures.

RESULTS:

There were 49 individuals who reported current adherence to a gluten-free diet reflecting a weighted prevalence of 0.548% (95% CI 0.206-0.889). The prevalence of a gluten-free diet was higher in females (0.58%) than males (0.37%), although this was not statistically significant (p = 0.34). Participants reporting a gluten-free diet were older (46.6 vs. 40.5 years, p = 0.005), had higher high-density lipoprotein, lower iron and lower body mass index.

CONCLUSIONS:

The estimated national prevalence of non-celiac gluten sensitivity is 0.548%, approximately half that of celiac disease. Future studies are merited in order to better understand the population burden of non-celiac gluten sensitivity."

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Non-celiac gluten sensitivity: clinical relevance and recommendations for future research.

Abstract

"BACKGROUND:

There has been increasing interest in the entity of Non-Celiac Gluten Sensitivity(NCGS) in recent years; however, it still remains a controversial topic and its pathogenesis is not well understood. Celiac Disease, in contrast, is a well-studied condition that has become increasingly recognized as a prevalent condition arising from a heightened immunological response to gluten. Wheat allergy is an IgE-mediated condition capable of causing a variety of gastrointestinal symptoms. However, the number of patients who have neither celiac disease nor wheat allergy, but appear to derive benefit from a gluten-free diet, is also increasing substantially. The use of the term NCGS as a way of describing this condition has become increasingly prevalent in recent years.

PURPOSE:

In this review, we will focus on gastrointestinal manifestations of NCGS and discuss the evidence for the condition and its putative pathogenesis. We will discuss areas of controversy and areas for potential future research."

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Non-celiac gluten sensitivity: the new frontier of gluten related disorders.

Abstract

"Non Celiac Gluten sensitivity (NCGS) was originally described in the 1980s and recently a "re-discovered" disorder characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food, in subjects that are not affected with either celiac disease (CD) or wheat allergy (WA). Although NCGS frequency is still unclear, epidemiological data have been generated that can help establishing the magnitude of the problem. Clinical studies further defined the identity of NCGS and its implications in human disease. An overlap between the irritable bowel syndrome (IBS) and NCGS has been detected, requiring even more stringent diagnostic criteria. Several studies suggested a relationship between NCGS and neuropsychiatric disorders, particularly autism and schizophrenia. The first case reports of NCGS in children have been described. Lack of biomarkers is still a major limitation of clinical studies, making it difficult to differentiate NCGS from other gluten related disorders. Recent studies raised the possibility that, beside gluten, wheat amylase-trypsin inhibitors and low-fermentable, poorly-absorbed, short-chain carbohydrates can contribute to symptoms (at least those related to IBS) experienced by NCGS patients. In this paper we report the major advances and current trends on NCGS."

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Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial.

Abstract

"OBJECTIVES:

Despite increased prescription of a gluten-free diet for gastrointestinal symptoms in individuals who do not have celiac disease, there is minimal evidence that suggests that gluten is a trigger. The aims of this study were to determine whether gluten ingestion can induce symptoms in non-celiac individuals and to examine the mechanism.

METHODS:

A double-blind, randomized, placebo-controlled rechallenge trial was undertaken in patients with irritable bowel syndrome in whom celiacdisease was excluded and who were symptomatically controlled on a gluten-free diet. Participants received either gluten or placebo in the form of two bread slices plus one muffin per day with a gluten-free diet for up to 6 weeks. Symptoms were evaluated using a visual analog scale and markers of intestinal inflammation, injury, and immune activation were monitored.

RESULTS:

A total of 34 patients (aged 29-59 years, 4 men) completed the study as per protocol. Overall, 56% had human leukocyte antigen (HLA)-DQ2 and/or HLA-DQ8. Adherence to diet and supplements was very high. Of 19 patients (68%) in the gluten group, 13 reported that symptoms were not adequately controlled compared with 6 of 15 (40%) on placebo (P=0.0001; generalized estimating equation). On a visual analog scale, patients were significantly worse with gluten within 1 week for overall symptoms (P=0.047), pain (P=0.016), bloating (P=0.031), satisfaction with stool consistency (P=0.024), and tiredness (P=0.001). Anti-gliadin antibodies were not induced. There were no significant changes in fecal lactoferrin, levels of celiac antibodies, highly sensitive C-reactive protein, or intestinal permeability. There were no differences in any end point in individuals with or without DQ2/DQ8.

CONCLUSIONS:

"Non-celiac gluten intolerance" may exist, but no clues to the mechanism were elucidated."

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