Gluten-free diet in French adults without coeliac disease: sociodemographic characteristics, motives and dietary profile

Impact of gluten intake on clinical outcomes in patients with chronic inflammatory diseases initiating biologics: Secondary analysis of the prospective multicentre BELIEVE cohort study

Chronic inflammatory diseases (CIDs) pose a growing healthcare challenge, with a substantial proportion of patients showing inadequate response to biological treatment. There is renewed interest in dietary changes to optimize treatment regimens, with a growing body of evidence suggesting beneficial effects with adherence to a gluten-free diet. This study compared the likelihood of achieving clinical response to biological treatment after 14-16 weeks in patients with CID with high versus low-to-medium gluten intake. Secondary outcomes of interest included changes in disease activity, health-related quality of life and C-reactive protein. The study was a multicentre prospective cohort of 193 participants with a CID diagnosis (i.e. Crohn's Disease, Ulcerative Colitis, Rheumatoid Arthritis, Axial Spondyloarthritis, Psoriatic Arthritis or Psoriasis) who initiated biological treatment between 2017 and 2020. Participants were stratified based on their habitual gluten intake: the upper 33.3% (high gluten intake) and the remaining 66.6% (low-to-medium gluten intake). The proportion of patients achieving clinical response to biological treatment after 14-16 weeks was compared using logistic regression models. The median gluten intake differed significantly between groups (12.5 g/day vs. 5.9 g/day, standardized mean difference = 1.399). In total, 108 (56%) achieved clinical response to treatment, with no difference between 35 (55%) in the high gluten group and 73 (57%) in the medium-to-low gluten group (OR = 0.96 [0.51-1.79], p = 0.897). No differences were found with secondary outcomes. In conclusion, this study found no association between gluten intake and response to biological treatment in patients with CID.

Effects of Short-Term Gluten-Free Diet on Cardiovascular Biomarkers and Quality of Life in Healthy Individuals: A Prospective Interventional Study

INTRODUCTION

The exposome concept includes nutrition as it significantly influences human health, impacting the onset and progression of diseases. Gluten-containing wheat products are an essential source of energy for the world's population. However, a rising number of non-celiac healthy individuals tend to reduce or completely avoid gluten-containing cereals for health reasons.

AIM AND METHODS

This prospective interventional human study aimed to investigate whether short-term gluten avoidance improves cardiovascular endpoints and quality of life (QoL) in healthy volunteers. A cohort of 27 participants followed a strict gluten-free diet (GFD) for four weeks. Endothelial function measured by flow-mediated vasodilation (FMD), blood testing, plasma proteomics (Olink®) and QoL as measured by the World Health Organisation Quality-of-Life (WHOQOL) survey were investigated.

RESULTS

GFD resulted in decreased leucocyte count and C-reactive protein levels along with a trend of reduced inflammation biomarkers determined by plasma proteomics. A positive trend indicated improvement in FMD, whereas other cardiovascular endpoints remained unchanged. In addition, no improvement in QoL was observed.

CONCLUSION

In healthy individuals, a short-term GFD demonstrated anti-inflammatory effects but did not result in overall cardiovascular improvement or enhanced quality of life.

Gluten and Wheat in Women's Health: Beyond the Gut

Since the rise of awareness of gluten/wheat-related disorders in the academic and clinical field in the last few decades, misinformation regarding the gluten-free diet (GFD) and its impact on health has been spreading among the general population. Despite the established link between gluten and celiac disease (CD), where a GFD is mandatory to reach clinical and histological remission, things are more complicated when it comes to non-celiac gluten/wheat sensitivity (NCGWS) and other autoimmune/dysimmune disorders. In the last conditions, a beneficial effect of gluten withdrawal has not been properly assessed, but still is often suggested without strong supporting evidence. In this context, women have always been exposed, more than men, to higher social pressure related to nutritional behaviors and greater engagement in controlling body weight. With this narrative review, we aim to summarize current evidence on the adherence to a GFD, with particular attention to the impact on women's health.

The Update of the Italian Food Composition Database of Gluten-Free Products and Its Application in Food-Based Dietary Guidelines Menus

Complete food composition databases (FCDBs) on gluten-free (GF) foods are needed to assess the nutrient intakes of celiac disease patients. The aim of the present work was to update the previously developed version of the Italian GF-FCDB and to apply it to a theoretical GF diet. The updated GF-FCDB includes the composition of 108 GF cereal-based foods, as sold, in terms of energy and macro- and micro-nutrients, imputed using food label information combined with the standard recipe approach. Three scenarios (i.e., refined, mixed, and wholegrain cereals) of the weekly guideline menu for the general Italian population were analyzed for energy and nutrient content in a theoretical dietary assessment using traditional gluten-containing (GC) foods and the corresponding GF substitutes. All GF menus were higher than the corresponding GC menus in polyunsaturated fatty acids, linoleic acid, and vitamin E. Zinc was lower in GF than in GC menus only in the wholegrain-cereal scenario. Thanks to the application of the updated GF-FCDB including a comprehensive list of micronutrients, we observed that it is possible for celiac disease patients to meet nutrient requirements by simply substituting GC with GF cereal-based products following recommendations for the general population.

The effect of gluten in adolescents and young adults with gastrointestinal symptoms: a blinded randomised cross-over trial

BACKGROUND

The popularity of the gluten-free diet and sales of gluten-free products have increased immensely.

AIMS

To investigate whether gluten induces gastrointestinal symptoms, measured by self-reported questionnaires, as well as mental health symptoms in adolescents from a population-based cohort.

METHODS

The eligible participants (n = 273) were recruited from a population-based cohort of 1266 adolescents and had at least four different gastrointestinal symptoms. Phase one (n = 54) was a run-in phase where the participants lived gluten-free for 2 weeks. If they improved they continued to phase 2 (n = 33), a blinded randomised cross-over trial. Participants were blindly randomised either to start with 7 days of gluten, eating two granola bars containing 10 g of gluten or to 7 days on placebo, eating two granola bars without gluten, followed by the reverse and separated by a 7-day washout period. The effects of the intervention on gastrointestinal symptoms and mental health symptoms were assessed.

RESULTS

In total, 54/273 participants entered the run-in phase and 35 were eligible for randomization. A total of 33 were randomised and 32 completed the trial. The median age was 20.3 (IQR 19.2-20.9) and 32/33 participants were females. Compared with a placebo, gluten did not induce gastrointestinal symptoms. The difference in the average VAS was -0.01 (95% confidence interval -2.07 to 2.05). Nor did we find a difference in the outcomes measuring mental health.

CONCLUSION

Compared with placebo, adding gluten to the diet did not induce gastrointestinal symptoms or worsened mental health in adolescents recruited from a population-based cohort. The trial registration number is NCT04639921.

Effects of a gluten-reduced or gluten-free diet for the primary prevention of cardiovascular disease

BACKGROUND

Cardiovascular diseases (CVD) are a major cause of disability and the leading cause of death worldwide. To reduce mortality and morbidity, prevention strategies such as following an optimal diet are crucial. In recent years, low-gluten and gluten-free diets have gained strong popularity in the general population. However, study results on the benefits of a gluten-reduced or gluten-free diet are conflicting, and it is unclear whether a gluten-reduced diet has an effect on the primary prevention of CVD.

OBJECTIVES

To determine the effects of a gluten-reduced or gluten-free diet for the primary prevention of CVD in the general population.

SEARCH METHODS

We systematically searched CENTRAL, MEDLINE, Embase, CINAHL and Web of Science up to June 2021 without language restrictions or restrictions regarding publication status. Additionally, we searched ClinicalTrials.gov for ongoing or unpublished trials and checked reference lists of included studies as well as relevant systematic reviews for additional studies.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs) and non-randomised studies of interventions (NRSIs), such as prospective cohort studies, comparing a low-gluten or gluten-free diet or providing advice to decrease gluten consumption with no intervention, diet as usual, or a reference gluten-intake category. The population of interest comprised adults from the general population, including those at increased risk for CVD (primary prevention). We excluded cluster-RCTs, case-control studies, studies focusing on participants with a previous myocardial infarction and/or stroke, participants who have undergone a revascularisation procedure as well as participants with angina or angiographically-defined coronary heart disease, with a confirmed diagnosis of coeliac disease or with type 1 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility of studies in a two-step procedure following Cochrane methods. Risk of bias (RoB) was assessed using the Cochrane risk of bias tool (RoB2) and the 'Risk Of Bias In Non-randomised Studies - of Interventions' (ROBINS-I) tool, and the certainty of evidence was rated using the GRADE approach.

MAIN RESULTS

One RCT and three NRSIs (with an observational design reporting data on four cohorts: Health Professionals Follow-up Study (HPFS), Nurses' Health Study (NHS-I), NHS-II, UK Biobank) met the inclusion criteria. The RCT was conducted in Italy (60 participants, mean age 41 ± 12.1 years), two NRSIs (three cohorts, HPFS, NHS-I, NHS II) were conducted across the USA (269,282 health professionals aged 24 to 75 years) and one NRSI (Biobank cohort) was conducted across the UK (159,265 participants aged 49 to 62 years). Two NRSIs reported that the lowest gluten intake ranged between 0.0 g/day and 3.4 g/day and the highest gluten intake between 6.2 g/day and 38.4 g/day. The NRSI reporting data from the UK Biobank referred to a median gluten intake of 8.5 g/day with an interquartile range from 5.1 g/day to 12.4 g/day without providing low- and high-intake categories. Cardiovascular mortality From a total of 269,282 participants, 3364 (1.3%) died due to cardiovascular events during 26 years of follow-up. Low-certainty evidence may show no association between gluten intake and cardiovascular mortality (adjusted hazard ratio (HR) for low- versus high-gluten intake 1.00, 95% confidence interval (CI) 0.95 to 1.06; 2 NRSIs (3 cohorts)). All-cause mortality From a total of 159,265 participants, 6259 (3.9%) died during 11.1 years of follow-up. Very low-certainty evidence suggested that it is unclear whether gluten intake is associated with all-cause mortality (adjusted HR for low vs high gluten intake 1.00, 95% CI 0.99 to 1.01; 1 NRSI (1 cohort)). Myocardial infarction  From a total of 110,017 participants, 4243 (3.9%) participants developed non-fatal myocardial infarction within 26 years. Low-certainty evidence suggested that gluten intake may not be associated with the development of non-fatal myocardial infarction (adjusted HR for low versus high gluten intake 0.99, 95% CI 0.89 to 1.10; 1 NRSI (2 cohorts)). Lowering gluten intake by 5 g/day also showed no association on the primary prevention of non-fatal and fatal myocardial infarction (composite endpoint) in linear dose-response meta-analyses (adjusted HR 1.02, 95% CI 0.98 to 1.06; 1 NRSI (2 cohorts)). Coronary risk factors  Type 2 diabetes From a total of 202,114 participants, 15,947 (8.0%) developed type 2 diabetes after a follow-up between 22 and 28 years. There was low-certainty evidence that a lower compared with a higher gluten intake may be associated with a slightly increased risk to develop type 2 diabetes (adjusted HR 1.14, 95% CI 1.07 to 1.22; 1 NRSI (3 cohorts)). Furthermore, lowering gluten intake by 5 g/day may be associated with a slightly increased risk to develop type 2 diabetes in linear dose-response meta-analyses (adjusted HR 1.12, 95% CI 1.08 to 1.16; 1 NRSI (3 cohorts)). Blood pressure, low-density lipoprotein level, body mass index (BMI) After six months of follow-up, very low-certainty evidence suggested that it is unclear whether gluten intake affects systolic blood pressure (mean difference (MD) -6.9, 95% CI -17.1 to 3.3 mmHg). There was also no difference between the interventions for diastolic blood pressure (MD -0.8, 95% CI -5.9 to 4.3 mmHg), low-density lipoprotein levels (MD -0.1, 95% CI -0.5 to 0.3 mmol/L) and BMI (MD -0.1, 95% CI -3.3 to 3.1 kg/m²).  No study reported data on adverse events or on other outcomes. Funding sources did not appear to have distorted the results in any of the studies.

AUTHORS' CONCLUSIONS

Very low-certainty evidence suggested that it is unclear whether gluten intake is associated with all-cause mortality. Our findings also indicate that low-certainty evidence may show little or no association between gluten intake and cardiovascular mortality and non-fatal myocardial infarction. Low-certainty evidence suggested that a lower compared with a higher gluten intake may be associated with a slightly increased risk to develop type 2 diabetes - a major cardiovascular risk factor. For other cardiovascular risk factors it is unclear whether there is a difference between a gluten-free and normal diet. Given the limited findings from this review predominantly based on observational studies, no recommendations for practice can be made.

The Effectiveness of Extruded-Cooked Lentil Flour in Preparing a Gluten-Free Pizza with Improved Nutritional Features and a Good Sensory Quality

Extruded-cooked lentil (ECL) flour was used to fortify (10/100 g dough) gluten-free pizza, which was compared with rice/corn-based pizza (control), and with pizza containing native lentil (NL) flour. Viscoamylograph and Mixolab data evidenced the hydrocolloid properties of ECL flour (initial viscosity = 69.3 BU), which contained pregelatinized starch. The use of ECL flour made it possible to eliminate hydroxymethylcellulose (E464), obtaining a clean label product. Both NL and ECL pizzas showed significantly (p < 0.05) higher contents of proteins (7.4 and 7.3/100 g, respectively) than the control pizza (4.4/100 g) and could be labelled as "source of proteins" according to the Regulation (EC) No. 1924/2006. In addition, NL and ECL pizzas were characterized by higher contents of bioactive compounds, including anthocyanins, and by higher in vitro antioxidant activity (1.42 and 1.35 µmol Trolox/g d.m., respectively) than the control pizza (1.07 µmol Trolox/g d.m.). However, NL and ECL pizzas also contained small amounts of undigestible oligosaccharides, typically present in lentils (verbascose = 0.92-0.98 mg/g d.m.; stachyose = 4.04-5.55 mg/g d.m.; and raffinose = 1.98-2.05 mg/g d.m.). No significant differences were observed in the liking level expressed by consumers between ECL and control pizzas.

Association between Self-Reported Gluten Avoidance and Irritable Bowel Syndrome: Findings of the NutriNet-Santé Study

Self-management of irritable bowel syndrome (IBS) is increasingly focusing on exclusion diets. In particular; patients are showing a significant interest in the gluten-free diet for the treatment of IBS. However; the lack of scientific evidence prevents the establishment of clear dietary guidelines and attention is needed as dietary restriction can lead to potentially adverse effects. This cross-sectional study aims to explore the practice of gluten avoidance in participants identified with IBS in a large cohort of non-celiac French adults. The population included 15,103 participants of the NutriNet-Santé study who completed a functional gastrointestinal disorder questionnaire based on the Rome III criteria to identify IBS in 2013 and a food avoidance questionnaire in 2016. Data on diet and anthropometric and sociodemographic characteristics were collected. Multivariate logistic regression models were used to compare the avoidance of gluten between IBS and non-IBS participants. Participants were mainly women (73.4%) and the mean age in this population was 55.8 ± 13.2 years. Among these individuals, 804 (5.4%) participants were identified as IBS cases. Among them, the prevalence of gluten avoidance was estimated at 14.8%, of which 3.0% reported total avoidance; versus 8.8% and 1.6% in non-IBS participants. After adjustments; gluten avoidance was higher in IBS participants compared to their non-IBS counterparts: (OR = 1.86; 95%CI = 1.21, 2.85) for total and (OR = 1.71; 95%CI = 1.36, 2.14) for partial avoidance. Participants identified with IBS were more associated with gluten avoidance than non-IBS participants. Further studies are needed to explore the long-term consequences of dietary interventions and to provide consistent dietary guidance connected to patient perception.

"The Gluten-Free Diet and Its Relationship with Metabolic Syndrome: Dietary Friend or Foe?"

PURPOSE OF REVIEW

Celiac disease (CD) is a prevalent digestive illness as well as a budding area of research in the field of gastroenterology. While investigations are underway to find new and improved pharmacological therapies for CD, the gluten-free diet (GFD) remains the only option to effectively manage the condition.

RECENT FINDINGS

While the GFD is recommended for patients diagnosed with CD and other gluten-related conditions, studies show the number of individuals on the GFD surpasses the projected number of patients with these medical indications (1). The implications of widespread adoption of this dietary approach are still being determined, with many patients believing this diet will improve overall health and cardiovascular risk. This review analyzes the relationship between a GFD and metabolic syndrome in both non-celiac and celiac patients, concluding that although the diet may slightly improve overall cardiac risk factors, weight, and/or insulin resistance, its use in the absence of a gluten-related disorder is controversial.

Organic food consumption and gluten-free diet, is there a link? Results in French adults without coeliac disease

The rising popular belief that gluten is unhealthy has led to growth in gluten avoidance in people without coeliac disease. Little information is available on their dietary profiles and their dietary behaviours. Our aim was to compare the consumption of organic foods between gluten avoiders and non-avoiders, and their places of food purchase. We described their sociodemographic and dietary profiles. The study population included participants of the NutriNet-Santé cohort who completed both a food exclusion questionnaire and an organic semi-quantitative FFQ (n 23 468). Food intake and organic food consumption ratios were compared using multivariable adjusted ANCOVA models. Associations between gluten avoidance and organic food consumption as well as places of food purchase were investigated with multivariable logistic regression. Participants avoiding gluten were more likely to be women and had a healthier dietary profile. Organic food consumption was higher among gluten avoiders (48·50 % of total diet for total avoiders, 17·38 % for non-avoiders). After adjustments for confounders, organic food consumption and purchase in organic stores were positively associated with gluten avoidance: adjusted OR (aOR)Q5 v.Q1 organic food = 4·95; 95 % CI 3·70, 6·63 and aORorganic stores v.supermarkets = 1·82; 95 % CI 1·42, 2·33 for total avoiders. Our study highlights that individuals avoiding gluten are high organic consumers and frequently purchase their foods in organic stores which propose an extended offer of gluten-free food. Further research is needed to determine the underlying common motivations and the temporality of the dietary behaviours of healthy people avoiding gluten.

Biostimulant impacts of Glutacetine® and derived formulations (VNT1 and VNT4) on the bread wheat grain proteome

Nitrogen (N) fertilizer is essential to ensure grain yield and quality in bread wheat. Improving N use efficiency is therefore crucial for wheat grain protein quality. In the present work, we analysed the effects on the winter wheat grain proteome of biostimulants containing Glutacetine® or two derived formulations (VNT1 and 4) when mixed with urea-ammonium-nitrate fertilizer. A large-scale quantitative proteomics analysis of two wheat flour fractions produced a dataset of 4369 identified proteins. Quantitative analysis revealed 9, 39 and 96 proteins with a significant change in abundance after Glutacetine®, VNT1 and VNT4 treatments, respectively, with a common set of 11 proteins that were affected by two different biostimulants. The major effects impacted proteins involved in (i) protein synthesis regulation (mainly ribosomal and binding proteins), (ii) defence and responses to stresses (including chitin-binding protein, heat shock 70 kDa protein 1 and glutathione S-transferase proteins), (iii) storage functions related to gluten protein alpha-gliadins and starch synthase and (iv) seed development with proteins implicated in protease activity, energy machinery, and the C and N metabolism pathways. Altogether, our study showed that Glutacetine®, VNT1 and VNT4 biostimulants positively affected protein composition related to grain quality. Data are available via ProteomeXchange with identifier PXD021513. SIGNIFICANCE: We performed a large-scale quantitative proteomics study of the total protein extracts from flour samples to determine the effect of Glutacetine®-based biostimulants treatment on the protein composition of bread wheat grain. To our knowledge, only a few studies in the literature have applied proteomic approaches to study bread wheat grains and in particular to investigate the effect of biostimulants on the grain proteome of this cereal crop. In addition, most approaches used fractional extraction of proteins to target reserve proteins followed electrophoresis which leads to low identification rate of proteins. We identified and quantified a large protein dataset of 4369 proteins and determined ontological class of proteins affected by biostimulants treatments. Our proteomics investigation revealed the important role of these new biostimulants in achieving significant changes in protein synthesis regulation, storage functions, protease activity, energy machinery, C and N metabolism pathways and responses to biotic and abiotic stresses in grain.

Genetic, lifestyle, and health-related characteristics of adults without celiac disease who follow a gluten-free diet: a population-based study of 124,447 participants

BACKGROUND

The number of gluten-free diet followers without celiac disease (CD) is increasing. However, little is known about the characteristics of these individuals.

OBJECTIVES

We address this issue by investigating a wide range of genetic and phenotypic characteristics in association with following a gluten-free diet.

METHODS

The cross-sectional association between lifestyle and health-related characteristics and following a gluten-free diet was investigated in 124,447 women and men aged 40-69 y from the population-based UK Biobank study. A genome-wide association study (GWAS) of following a gluten-free diet was performed.

RESULTS

A total of 1776 (1.4%) participants reported following a gluten-free diet. Gluten-free diet followers were more likely to be women, nonwhite, highly educated, living in more socioeconomically deprived areas, former smokers, have lost weight in the past year, have poorer self-reported health, and have made dietary changes as a result of illness. Conversely, these individuals were less likely to consume alcohol daily, be overweight or obese, have hypertension, or use cholesterol-lowering medication. Participants with hospital inpatient diagnosed blood and immune mechanism disorders (OR: 1.62; 95% CI: 1.18, 2.21) and non-CD digestive system diseases (OR: 1.58; 95% CI: 1.42, 1.77) were more likely to follow a gluten-free diet. The GWAS demonstrated that no genetic variants were associated with being a gluten-free diet follower.

CONCLUSIONS

Gluten-free diet followers have a better cardiovascular risk profile than non-gluten-free diet followers but poorer self-reported health and a higher prevalence of blood and immune disorders and digestive conditions. Reasons for following a gluten-free diet warrant further investigation.

Biostimulant Effects of Glutacetine® and Its Derived Formulations Mixed With N Fertilizer on Post-heading N Uptake and Remobilization, Seed Yield, and Grain Quality in Winter Wheat

Biostimulants could play an important role in agriculture particularly for increasing N fertilizer use efficiency that is essential for maintaining both yield and grain quality in bread wheat, which is a major global crop. In the present study, we examined the effects of mixing urea-ammonium-nitrate fertilizer (UAN) or urea with five new biostimulants containing Glutacetine® or its derivative formulations (VNT1, 2, 3, and 4) on the physiological responses, agronomic traits, and grain quality of winter wheat. A first experiment under greenhouse conditions showed that VNT1, VNT3, and VNT4 significantly increased the seed yield and grain numbers per ear. VNT4 also enhanced total plant nitrogen (N) and total grain N, which induced a higher N Harvest Index (NHI). The higher post-heading N uptake (for VNT1 and VNT4) and the acceleration of senescence speed with all formulations enabled better nutrient remobilization efficiency, especially in terms of N mobilization from roots and straw toward the grain with VNT4. The grain ionome was changed by the formulations with the bioavailability of iron improved with the addition of VNT4, and the phytate concentrations in flour were reduced by VNT1 and VNT4. A second experiment in three contrasting field trials confirmed that VNT4 increased seed yield and N use efficiency. Our investigation reveals the important role of these new formulations in achieving significant increases in seed yield and grain quality.

Gluten-Free Products: From Dietary Necessity to Premium Price Extraction Tool

Every year, the Italian National Health Service (NHS) provides about 200,000 celiac people (based on 2017 data) living in Italy with financial support of about 250 million euro to cover the cost of their specific dietary constrains. The existence of gluten-free products of high quality and affordable price is very important for the quality of life of celiac people and the sustainability of public support. Over the last decade, the market for gluten-free products has experienced a dramatic surge, with an increasing shelf space dedicated to these products in supermarkets, and a large variety of products both in terms of kind of agricultural inputs and processing and packaging methods. This study aimed at assessing the offer of gluten-free (GF) pasta in Italian supermarkets, with respect to its ability to meet the needs of celiac people in terms of variety, prices and safety. A hedonic price analysis was performed. Results indicated that GF pasta is sold only in 44% of the 212 stores of the sample, with a price equal to more than twice that of conventional pasta. A premium price was found for the following attributes: small packages, brands specialized in GF products, content in fiber and the presence of quinoa as ingredient.