Relationship of asthma and rhinoconjunctivitis with obesity, exercise and Mediterranean diet in Spanish schoolchildren

Association between DASH diet and asthma symptoms among a large sample of adolescents: a cross-sectional study

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) diet, which has a lot of emphasis on the consumption of fruits, vegetables, and whole grains, and on the other hand, the consumption of red meat and sodium is limited, due to its anti-inflammatory properties, which can be related to reducing the risk of asthma.

OBJECTIVES

The aim of this study was to determine the relationship between the DASH diet and asthma symptoms among children and adolescents.

METHODS

This cross-sectional study was conducted among7667 children (3414 boys and 4253 girls) aged 6-7 and 13-14 years living in central Iran. Dietary food consumption was assessed using a multiple-choice questionnaire. Logistic regression was used to obtain odds ratios for the association between the DASH-like diet with current asthma and asthma symptoms.

RESULTS

Our findings revealed that higher adherence to a DASH-like diet resulted in lower odds of asthma confirmed by a doctor among the whole population (OR = 0.53; 95%CI: 0.36-0.76) and also in females (OR = 0.47; 95%CI: 0.29-0.78). Moreover, the higher adherence to the DASH-like diet was inversely associated with the chance of wheezing in the past 12 months in all subjects (OR = 0.67; 95%CI: 0.51-0.86) and in boys (OR = 0.57; 95%CI: 0.38-0.85).

CONCLUSION

The findings of the present study showed that following the DASH diet can be associated with the improvement of asthma symptoms in children and adolescents. However, more research is needed to improve dietary recommendations for asthma prevention.

Greenness and its composition and configuration in association with allergic rhinitis in preschool children

BACKGROUND

Few studies focus on the associations of green space composition and configuration with children's allergic rhinitis (AR).

METHODS

A multi-center population-based cross-sectional study was performed in 7 cities in mainland of China between 2019 and 2020, recruiting 36,867 preschool children. Information on the current AR symptoms and demographics were collected by questionnaire. Exposure to residential greenness was estimated by Normalized Difference Vegetation Index (NDVI, 1000 m buffer) around the residences. Greenness composition was estimated in 3 main categories: forest, grassland, shrubland. Configuration of each category and total greenness (a spatial resolution of 10 m × 10 m) was estimated by 6 landscape pattern metrics to quantify their area, shape complexity, aggregation, connectivity, and patch density. Exposure to daily ambient particulate matter (PM1, PM2.5 and PM10, a spatial resolution of 1 km × 1 km) was estimated. Multilevel logistic regression models were applied to analyze the associations of greenness and its composition and configuration with AR, and mediation effects by PMs were examined by mediation analysis models.

RESULTS

The prevalence of self-reported current AR in preschool children was 33.1%. Two indicators of forest, Aggregation Index of forest patches (AIforest) (odds ratio (OR):0.92, 95% Confidential Interval (CI): 0.88-0.97), and Patch Cohesion of forest (COHESIONforest) (OR: 0.93, 95% CI:0.89-0.98) showed significantly negative associations with AR symptoms. Mediation analyses found the associations were partially mediated by PMs. Age, exclusive breastfeed duration and season were the potential effect modifiers. The associations varied across seven cities.

CONCLUSION

Our findings suggest the inverse associations of the aggregation and connectivity of forest patches surrounding residence addresses with AR symptoms. Since the cross-sectional study only provides associations rather than causation, further studies are needed to confirm our results as well as the underlying mechanisms.

Greater fruit and vegetables consumption, and adherence to a Mediterranean type of diet reduces the risk for asthma in children; a systematic review and meta-analysis

The objective of this study was to explore the relationship between the consumption of fruits, vegetables and adherence to the Mediterranean diet with childhood asthma development and severity. A systematic literature search and synthesis of the results was performed throughout the last two decades. A total of 45 studies were analysed and 392,797 children were included. Greater adherence to a Mediterranean type of diet was inversely associated with asthmatic outcomes (OR:0.71,95% CI:0.54,0.88). Regarding fruits, vegetables consumption, a significant inverse association between increased fruits or vegetable intake and asthma was found (OR:0.82,95% CI:0.77,0.86; 0.84,95% CI:0.77,0.91, respectively). Fruits and vegetables consumption combined was also inversely related to all asthmatic outcomes (OR:0.65,95% CI:0.49,0.78). The level of heterogeneity was moderate-to-high (30%-97%). The present review and meta-analysis show a trend to an inverse association between adherence to the Mediterranean diet or a healthy diet rich in fruits and vegetables and the occurrence of childhood asthma but with a low level of certainty.

Prevalence, severity, and risk factors of allergic rhinitis among schoolchildren in Saudi Arabia: A national cross-sectional study, 2019

Background

Allergic rhinitis is a significant public health concern worldwide, affecting both developed and developing countries, with prevalence rates ranging between 10% and 30% in adults and over 40% in children. However, there are limited studies on allergic rhinitis prevalence in Saudi Arabia.

Objective

To explore allergic rhinitis among schoolchildren in Saudi Arabia in terms of prevalence, severity, and risk factors.

Methods

This study was conducted between March and April 2019, covering 20 regions. The study employed a multistage, stratified cluster sampling approach and selected 137 primary and 140 intermediate schools. The research utilized the methodology and questionnaires recommended by the Global Asthma Network (GAN). Data analysis was carried out using IBM SPSS Statistics (Version 23).

Results

The completed questionnaires in the analysis comprised 3614 children aged 6-7 years old and 4068 adolescents aged 13-14 years old. The study found that 5.6% of children and 14.0% of adolescents reported current rhinoconjunctivitis, with 0.5% of children and 1.3% of adolescents experiencing severe symptoms. Several risk factors were significantly associated with rhinoconjunctivitis. In children 6-7 years old, eating cooked vegetables was inversely associated with rhinoconjunctivitis, while prematurity, wheezing in infancy, and a history of pneumonia were positively associated with the condition. In adolescents, vigorous physical activity, current exposure to cats, and frequent use of paracetamol were found to be the main risk factors associated with rhinoconjunctivitis, while high consumption of pulses and eggs was found to have a protective effect.

Conclusion

In Saudi Arabia, the prevalence of rhinoconjunctivitis in children is lower than average globally, but among adolescents, it is within the global average range. However, the prevalence of severe rhinoconjunctivitis among adolescents is twice the global average. Further research is required to examine regional differences, track trends over time, and explore risk factors that contribute to allergic rhinitis.

The Effects of a Healthy Diet on Asthma and Wheezing in Children and Adolescents: A Systematic Review and Meta-Analysis

Background

Asthma is a public health problem requiring focused attention. This study aimed to systematically evaluate the association between dietary structure and asthma or wheezing in children.

Methods

The study protocol of this meta-analysis has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) with the registration code CRD42023390191. A total of 8397 articles were retrieved, searching PubMed, Medline, Embase, Web of Science, and Scopus databases as of November 21, 2022. Two independent authors were responsible for independently conducting the literature screening process. Effect-size estimates were expressed as odds ratio (OR) in cross-sectional studies and risk ratio (RR) in cohort studies with a 95% confidence interval (CI). Summary effect estimates were evaluated with random-effect models. Meanwhile, subgroup and sensitivity analyses were performed to assess the potential sources of heterogeneity and the robustness of the pooled estimation.

Results

A total of 65 studies, including 567,426 subjects had been analyzed. Overall analyses of cross-sectional studies revealed that a healthy diet was protective against asthma (adjusted OR=0.85, 95% CI: 0.80-0.89, P <0.001, I2=69.8%, Tau2=0.026) and wheezing (adjusted OR=0.85, 95% CI: 0.81-0.89, P <0.001, I2=66.8%, Tau2=0.015) in children and adolescents. Conversely, unhealthy diets can exacerbate asthma (adjusted OR=1.28, 95% CI: 1.20-1.36, P <0.001, I2=64.9%, Tau2=0.019) and wheeze (adjusted OR=1.09, 95% CI: 1.02-1.16, P =0.006, I2=75.2%, Tau2=0.023) in children and adolescents. The same trend was found in cohort studies (adjusted RR=0.72, 95% CI: 0.58-0.90, P =0.003, I2=83.5%, Tau2=0.105). A clear trend was observed between high-frequency healthy diets (OR=0.80; 95% CI: 0.71-0.89; P <0.001) is more protective against asthma than low-frequency healthy diets (OR=0.81; 95% CI: 0.70-0.94; P =0.007).

Conclusion

Our findings highlight the protective effects of a healthy diet on asthma and wheezing in children, including fruit, seafood, cereals, and the Mediterranean diet.

Prevalence and time trends of symptoms of allergic rhinitis and rhinoconjunctivitis in Spanish children: Global Asthma Network (GAN) study

INTRODUCTION

The time trends of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy previously described in the ISAAC (International Study of Asthma and Allergies in Childhood) in 2002 are unknown; or if the geographical or age differences in Spain persist.

OBJECTIVE

To describe the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy in different Spanish geographical areas and compare them with those of the ISAAC.

METHODS

Cross-sectional study of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy, carried out in 2016-2019 on 19943 adolescents aged 13-14 years and 17215 schoolchildren aged 6-7 years from six Spanish areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona, and Salamanca), through a questionnaire based on the Global Asthma Network (GAN) protocol.

RESULTS

The prevalences of recent rhinitis and rhinoconjunctivitis (last 12 months), and nasal allergy/hay fever were 35.1%, 17.6%, and 14.6% in the adolescents and 20%, 8.5%, and 8.9% in the schoolchildren, respectively, with rhinoconjunctivitis in adolescents varying from 20.9% in Bilbao to 13.4% in Cartagena; and in schoolchildren, from 9.8% in La Coruña to 6.4% in Pamplona. These prevalences of rhinoconjunctivitis and nasal allergy in adolescents were higher than those described in the ISAAC (16.3% and 13%) and similar in schoolchildren to the ISAAC (9% and 9.4%).

CONCLUSIONS

There has been a stabilisation of rhinitis, rhinoconjunctivitis and nasal allergy in schoolchildren that slows the previous upward trend of ISAAC; and a slight non-significant increase in rhinoconjunctivitis and nasal allergy in adolescents. The variability found in adolescents would require local research to be better understood.

Air Pollution and Diet: Potential Interacting Exposures in Asthma

PURPOSE OF REVIEW

To provide a review of emerging literature describing the impact of diet on the respiratory response to air pollution in asthma.

RECENT FINDINGS

Asthma phenotyping (observable characteristics) and endotyping (mechanistic pathways) have increased the specificity of diagnostic and treatment pathways and opened the doors to the identification of subphenotypes with enhanced susceptibility to exposures and interventions. Mechanisms underlying the airway immune response to air pollution are still being defined but include oxidative stress, inflammation, and activation of adaptive and innate immune responses, with genetic susceptibility highlighted. Of these, neutrophil recruitment and activation appear prominent; however, understanding neutrophil function in response to pollutant exposures is a research gap. Diet may play a role in asthma pathogenesis and morbidity; therefore, diet modification is a potential target opportunity to protect against pollutant-induced lung injury. In particular, in vivo and in vitro data suggest the potential for diet to modify the inflammatory response in the airways, including impacts on neutrophil recruitment and function. Murine models provide compelling results in regard to the potential for dietary components (including fiber, antioxidants, and omega-3 fatty acids) to buffer against the inflammatory response to air pollution in the lung. Precision lifestyle approaches to asthma management and respiratory protection in the context of air pollution exposures may evolve to include diet, pending the results of further epidemiologic and causal investigation and with neutrophil recruitment and activation as a candidate mechanism.

Consumption of milk and dairy products and risk of asthma in children: a systematic review and Meta-analysis

BACKGROUND

Some reports demonstrate that asthma benefits from milk and dairy products, however, the findings are controversial. We used meta-analysis as a tool to summarize published data on the association between dairy products consumption and asthma.

METHODS

A systematic literature search was conducted to identify studies of dairy products and asthma in children in PubMed, ISI (Web of Science), and EMBASE until 21 July 2022. Random-effect meta-analyses with summarized data were performed for total (high/low) milk and dairy intake. Subgroup analysis was used to identify sources of variation in responses. Publication bias and sensitivity analysis were done to examine the stability of results.

RESULTS

There was no correlation between consumption of dairy products and reduced risk of asthma (OR = 0.82; 95% CI: 0.60-1.05). Our results revealed that elevated consumption of milk and dairy has significant correlation with reduced risk of asthma in Non-Asian population (OR = 0.74; 95% CI = 0.51-0.96) and high quality studies (OR = 0.73; 95% CI = 0.50-0.95). No individual study influence and publication bias was seen in the sensitivity analysis and publication bias assessment.

CONCLUSION

There was no correlation between consumption of dairy products and reduced risk of asthma. However, we observed that elevated consumption of milk and dairy has significant correlation with reduced risk of asthma in Non-Asian population and high quality studies. More high-quality and population-specific studies should be conducted to determine the risk link between milk consumption and asthma in children.

Meta-omics profiling of the gut-lung axis illuminates metabolic networks and host-microbial interactions associated with elevated lung elastance in a murine model of obese allergic asthma

Obesity and associated changes to the gut microbiome worsen airway inflammation and hyperresponsiveness in asthma. Obesogenic host-microbial metabolomes have altered production of metabolites that may influence lung function and inflammatory responses in asthma. To understand the interplay of the gut microbiome, metabolism, and host inflammation in obesity-associated asthma, we used a multi-omics approach to profile the gut-lung axis in the setting of allergic airway disease and diet-induced obesity. We evaluated an immunomodulator, nitro-oleic acid (NO₂-OA), as a host- and microbial-targeted treatment intervention for obesity-associated allergic asthma. Allergic airway disease was induced using house dust mite and cholera toxin adjuvant in C57BL6/J mice with diet-induced obesity to model obesity-associated asthma. Lung function was measured by flexiVent following a week of NO₂-OA treatment and allergen challenge. 16S rRNA gene (from DNA, taxa presence) and 16S rRNA (from RNA, taxa activity) sequencing, metabolomics, and host gene expression were paired with a Treatment-Measured-Response model as a data integration framework for identifying latent/hidden relationships with linear regression among variables identified from high-dimensional meta-omics datasets. Targeting both the host and gut microbiota, NO₂-OA attenuated airway inflammation, improved lung elastance, and modified the gut microbiome. Meta-omics data integration and modeling determined that gut-associated inflammation, metabolites, and functionally active gut microbiota were linked to lung function outcomes. Using Treatment-Measured-Response modeling and meta-omics profiling of the gut-lung axis, we uncovered a previously hidden network of interactions between gut levels of amino acid metabolites involved in elastin and collagen synthesis, gut microbiota, NO₂-OA, and lung elastance. Further targeted metabolomics analyses revealed that obese mice with allergic airway disease had higher levels of proline and hydroxyproline in the lungs. NO₂-OA treatment reduced proline biosynthesis by downregulation of pyrroline-5-carboxylate reductase 1 (PYCR1) expression. These findings are relevant to human disease: adults with mild-moderate asthma and BMI ≥ 25 had higher plasma hydroxyproline levels. Our results suggest that changes to structural proteins in the lung airways and parenchyma may contribute to heightened lung elastance and serve as a potential therapeutic target for obese allergic asthma.

The Impact of Dietary Intervention in Obese Children on Asthma Prevention and Control

The prevalence of both asthma and obesity in the pediatric population is steadily increasing, and even the obese-asthma phenotypes are postulated. Obese children with asthma experience more asthma symptoms, more frequent exacerbations, and worse response to treatment; they also report a lower quality of life compared with lean asthmatics. Some of the etiological factors for asthma and obesity may overlap. Perhaps asthma and obesity share a common genetic and immunologic origin. Diet is a compelling modifiable factor in obesity and asthma prevention and control, although the relationship between these two diseases is certainly multifactorial. In this article, we analyze the impact of dietary intervention and weight loss in obese children on asthma prevention and control.

Allergic rhinitis in Chinese young adults from the Singapore/Malaysia cross-sectional genetics epidemiology study (SMCGES) cohort: Prevalence, patterns, and epidemiology of allergic rhinitis

Background

Allergic rhinitis (AR) is characterized by the occurrence of at least 2 symptoms of nasal itching, nasal blockage, rhinorrhea, and sneezing, when not afflicted with a cold or flu, with defined atopic sensitization demonstrated by skin prick test or specific IgE responses. Besides the detriment to standard of living and economic burden of AR, both multicentre and single-cohort studies have observed an increase in AR prevalence in Asia over time.

Methods

In total, 12 872 individuals, with mean age 22.1 years (SD = 4.8), were recruited from universities in Singapore and Malaysia. Each participant provided epidemiological data based on an investigator-administered questionnaire adapted from the validated International Study of Allergies and Asthma in Childhood (ISAAC) protocol, and atopy status was determined using a skin prick test (SPT) performed by qualified staff. AR was diagnosed according to Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines and a positive SPT result.

Results

Sensitization (determined by SPT) to either Blomia tropicalis or Dermatophagoides pteronyssinus was prevalent in 66.5% of the cohort. Current rhinitis (manifesting ≥2 rhinitis symptoms, within the past 12 months) was observed in 48.9% of our population, while AR, which included atopy status, was estimated at 39.4%. Sneezing and rhinorrhea were the most common symptoms among AR cases. AR prevalence decreased with increasing age (OR: 0.979; 95% CI: 0.969-0.989), while male gender (OR: 2.053; 95% CI: 1.839-2.294), and a parental history of allergic diseases (OR: 2.750; 95% CI: 2.284-3.316) were significant risk factors for AR. Upon adjustment for age, gender, and parental history, housing type (OR: 0.632; 95% CI: 0.543-0.736) and income level (>$6000 vs <$2000; OR: 2.461; 95% CI: 2.058-2.947) remained as significant risk factors for AR, while ever having kept a pet (OR: 1.167; 95% CI: 1.025-1.328) emerged as a risk factor. Conflicting results were obtained for indicators of sedentary lifestyle: frequent physical activity (OR: 1.394; 95% CI: 1.150-1.694) and increased duration spent using the TV/computer (OR: 1.224; 95% CI: 1.006-1.489) both increased the risk of AR. Lastly, we used the Quality of Diet based on Glycaemic Index Score (QDGIS) to assess the Glycaemic Index (GI) level of overall diet. We identified lower GI level of overall diet as a protective factor against AR manifestation (OR: 0.682; 95% CI: 0.577-0.807).

Conclusion

While the previously established non-modifiable risk factors for AR were present in our study population, the identification of modifiable risk factors, such as TV/computer usage, and dietary habits, opens a new area for research, both in the areas of gene-environment interaction, and management of AR.

Influence of the mother's lifestyles on the initiation of breastfeeding: A case-control study

INTRODUCTION

Breast milk is the optimal food during the first months of life. The main objective was to analyse the factors associated with not initiating breastfeeding in terms of maternal lifestyles, epidemiological characteristics and information on breastfeeding.

MATERIAL AND METHOD

Observational analytical study of cases and controls in 6 primary care centres. The sample included women with a child under 5 years, with an estimated necessary sample size of 166 cases (women who did not initiate breastfeeding) and 166 controls (women who began breastfeeding). Sociodemographic and maternal lifestyle variables were measured before and during pregnancy, such as physical activity using the BPAAT questionnaire, diet with the MEDAS-14 questionnaire, and tobacco and alcohol consumption. We assessed the information and opinions about breastfeeding as well as previous experience with it.

RESULTS

The study included 348 women (174 cases and 174 controls) with a mean age of 33.4 years (SD, 5.4). The variables independently associated with not initiating breastfeeding were: absence of previous experience with breastfeeding (odds ratio [OR], 12.75), making the decision during pregnancy or delivery (OR, 10.55), not being married or in a partnership (OR, 3.42) and being sedentary for periods of 2 hours or greater/day during pregnancy (OR, 1.77).

CONCLUSIONS

In our study, the determining factors associated with not initiating breastfeeding were the lack of previous experience with breastfeeding, the timing of the decision about breastfeeding, and marital status. When it came to lifestyle, only a sedentary lifestyle was associated with not initiating breastfeeding, while dietary or other habits had no influence.

Prevalence and temporal evolution of asthma symptoms in Spain. Global Asthma Network (GAN) study

INTRODUCTION

The temporal evolution of the prevalence of asthma described in the ISAAC (International Study of Asthma and Allergies in Childhood) in 2002 is unknown, or if the geographical or age differences are maintained in Spain.

OBJECTIVE

To describe the prevalence of asthma symptoms in different Spanish geographic areas and compare it with that of those centers that participated in the ISAAC.

METHODS

Cross-sectional study of asthma prevalence, carried out in 2016-2019 with 19,943 adolescents aged 13-14 years and 17,215 schoolchildren aged 6-7 years from 6 Spanish geographical areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona and Salamanca). Asthma symptoms were collected using a written questionnaire and video questionnaire according to the Global Asthma Network (GAN) protocol.

RESULTS

The prevalence of recent wheezing (last 12 months) was 15.3% at 13-14 years and 10.4% at 6-7 years, with variations in adolescents, from 19% in Bilbao to 10.2% in Cartagena; and in schoolchildren, from 11.7% in Cartagena to 7% in Pamplona. These prevalences were higher than those of the ISAAC (10.6% in adolescents and 9.9% in schoolchildren). 21.3% of adolescents and 12.4% of schoolchildren reported asthma at some time.

CONCLUSIONS

There is a high prevalence of asthmatic symptoms with an increase in adolescents and a stabilization in Spanish schoolchildren with respect to the ISAAC. Geographic variations in asthma prevalence are not so clearly appreciated, but areas with high prevalences maintain high numbers.

Does Adherence to the Mediterranean Diet Have a Protective Effect against Asthma and Allergies in Children? A Systematic Review

Dietary pattern may potentially impact on the pathogenesis of asthma and allergies. The Mediterranean Diet (MD) has significant health benefits due to its antioxidant and anti-inflammatory properties. The aim of this systematic review was to investigate the effectiveness of adherence to the MD against asthma and allergies in childhood. Hence, a systematic literature search was conducted on PubMed, ESBCO (Cinahl), Scopus, and the Cochrane Library databases up to 26 January 2022. The total number of articles obtained, after the initial search on the databases was conducted, was 301. Twelve studies were included, after the removal of duplicates and screening for eligibility. Our findings indicated a protective role of the MD against childhood asthma, but they also imply that the MD probably does not affect the development of allergies. Nevertheless, the heterogeneity and limitations of the studies highlight the need for randomized controlled trials that will focus on the pediatric population and hopefully provide more robust evidence.

Nutrition in Asthma

An emerging body of evidence suggests that diet plays an important role in both the development and management of asthma. The relationship between dietary intake and asthma risk has been explored in epidemiological studies, though intervention trials examining the effects of nutrient intake and dietary patterns on asthma management are scarce. Evidence for diets high in fruits and vegetables, antioxidants, omega-3 fatty acids and soluble fiber such as the Mediterranean diet is conflicting. However, some studies suggest that these diets may reduce the risk of asthma, particularly in young children, and could have positive effects on disease management. In contrast, a Westernized dietary pattern, high in saturated fatty acids, refined grains, and sugars may promote an inflammatory environment resulting in the onset of disease and worsening of asthma outcomes. This review will summarize the state of the evidence for the impact of whole dietary patterns, as well as individual nutrients on the prevalence and management of asthma.

Allergic Diseases: A Comprehensive Review on Risk Factors, Immunological Mechanisms, Link with COVID-19, Potential Treatments, and Role of Allergen Bioinformatics

The prevalence of allergic diseases is regarded as one of the key challenges in health worldwide. Although the precise mechanisms underlying this rapid increase in prevalence are unknown, emerging evidence suggests that genetic and environmental factors play a significant role. The immune system, microbiota, viruses, and bacteria have all been linked to the onset of allergy disorders in recent years. Avoiding allergen exposure is the best treatment option; however, steroids, antihistamines, and other symptom-relieving drugs are also used. Allergen bioinformatics encompasses both computational tools/methods and allergen-related data resources for managing, archiving, and analyzing allergological data. This study highlights allergy-promoting mechanisms, algorithms, and concepts in allergen bioinformatics, as well as major areas for future research in the field of allergology.

Mediterranean diet and lung function, sensitization, and asthma at school age: The PARIS cohort

BACKGROUND

The Mediterranean diet (MD) has known health benefits, but its specific impact on allergy development is unclear. As part of the PARIS birth cohort follow-up, we aimed to investigate the adherence of 8-year-old children to the MD and its association with allergic/respiratory morbidity at school age.

METHODS

Diet was assessed using a food frequency questionnaire completed by the parents. Adherence to the MD was assessed based on two scores: the KIDMED index and the Mediterranean Diet Score (MDS). Current allergic diseases (asthma, rhinitis, eczema), lung function indices (FEV₁ and FVC), FeNO and specific IgE levels were determined during a health check-up at 8 years. Associations between levels of adherence to the MD and respiratory/allergic morbidity were studied using multivariable logistic and linear regression models adjusted for potential confounders.

RESULTS

A total of 975 children were included in the present study, 35.6% with low adherence to the MD, 55.7% with moderate adherence and 8.7% with high adherence according to the KIDMED index. High family socioeconomic status, any breastfeeding at 6 months and consumption of organic food were associated with higher adherence to the MD. Compared with low adherence, high adherence was associated with lower risk of asthma and sensitization at 8 years, as well as higher FEV₁ and FVC.

CONCLUSION

This study suggests a protective effect of high adherence to the MD on allergic and respiratory morbidity at school age. These results need to be confirmed by further longitudinal analyses. A healthy diet may prevent allergic and respiratory morbidity in school-aged children.

The Role of Nutritional Factors in Asthma: Challenges and Opportunities for Epidemiological Research

The prevalence of asthma has nearly doubled over the last decades. Twentieth century changes in environmental and lifestyle factors, including changes in dietary habits, physical activity and the obesity epidemic, have been suggested to play a role in the increase of asthma prevalence and uncontrolled asthma worldwide. A large body of evidence has suggested that obesity is a likely risk factor for asthma, but mechanisms are still unclear. Regarding diet and physical activity, the literature remains inconclusive. Although the investigation of nutritional factors as a whole (i.e., the “diet, physical activity and body composition” triad) is highly relevant in terms of understanding underlying mechanisms, as well as designing effective public health interventions, their combined effects across the life course has not received a lot of attention. In this review, we discuss the state of the art regarding the role of nutritional factors in asthma, for each window of exposure. We focus on the methodological and conceptual challenges encountered in the investigation of the complex time-dependent interrelations between nutritional factors and asthma and its control, and their interaction with other determinants of asthma. Lastly, we provide guidance on how to address these challenges, as well as suggestions for future research.

[Diet and asthma: Better eating for better breathing?]

Inhaled therapies are the cornerstone of asthma treatment. However, according to national and international guidelines, non-pharmacological interventions should not be neglected in asthma. It has been demonstrated that a healthy diet is beneficial to general health. Recently, the effect of diet on asthma has been highlighted in many studies. Two diets have been particularly studied: the Mediterranean diet (high in fruits and vegetables and low in fat) and the Western diet (high in saturated fat and low in fruits and vegetables). A beneficial effect of the Mediterranean diet and deleterious effect of the Western diet on the development or control of asthma has been shown in some studies even after adjustment for overweight. Study findings have not been unanimous, probably related to the complexity of conducting studies on a diet that may change from day to day for any individual subject. In addition, the effect of physical exercise, which is known to be beneficial in asthma, is rarely taken into account in these studies. However, studies on diet are becoming more complex with the use of specific dietary indices, which should bring interesting data in the future.

Weight loss in obese children with asthma - is it important?

Obesity is a significant public health problem worldwide, and it has been identified as an independent risk factor for asthma in both adults and children. Not only does obesity increase asthma risk, but it is also associated with decreased asthma-related quality of life, worsened symptoms and asthma control, increased frequency and severity of asthma exacerbations and reduced response to asthma medications. In this review we examine the epidemiology and implications of obesity in both children and adults with asthma, and how the obesogenic "western" diet contributes to asthma prevalence and progression. Finally, we summarise the current evidence on the impact of weight loss on asthma outcomes in both adults and children, highlighting the need for further research to be conducted in the paediatric population.

Diet Modifications in Primary Prevention of Asthma. Where Do We Stand?

The steep increase in asthma prevalence, observed worldwide in recent decades, has created an urgent need to search for effective methods of its prevention. Among other environmental factors, changes in diet habits and the potential influence of individual food components on immunological processes have been extensively studied as a potential method of intervention in primary prevention of asthma. The preventive role of some nutrients has been confirmed: unpasteurized milk reduced the risk of asthma in epidemiological studies, vitamin D supplementation was effective in preventing the transient forms of wheezing in small children and high maternal intake of fish oil reduced the risk of persistent wheeze and asthma in children. However, not all studies provided consistent results, and many food ingredients are still pending for defining their role in asthma development. Moreover, a novel approach looking not only at single food ingredients, but the whole dietary patterns and diversity has recently been proposed. In this paper, we discuss the current role of nutrients in asthma primary prevention and the reasons for inconsistencies in the study results. We look at single diet components, but also the whole dietary patterns. We describe the proposed mechanisms of action at different stages of life, identify the role of modifiers and delineate future perspectives on the application of nutrients in targeting strategies for asthma primary prevention.

Association between Allergic Rhinitis and Regular Physical Activity in Adults: A Nationwide Cross-Sectional Study

Evidence regarding the association between allergic rhinitis (AR) and physical activity (PA) is conflicting. Previous studies have mostly relied only on self-reported symptoms to define AR, did not classify AR by severity or persistence, and included only children or athletes. The present cross-sectional study evaluated the association between PA and objectively-defined AR and its subtypes in the general adult population using data for 1932 eligible participants aged 19 years or older in the 2010 Korea National Health and Nutrition Examination Survey. Multivariable logistic regression analyses were performed to evaluate the relationship between three types of PA and overall AR, AR subtypes, and rhinoscopy findings showed that moderate-severe AR was positively associated with vigorous (odds ratio [OR] = 3.392, p = 0.002) and moderate (OR = 3.623, p = 0.007) PA compared to mild AR, while persistent AR was associated with vigorous (OR = 3.954, p = 0.004) and moderate (OR = 3.411, p = 0.022) PA compared to intermittent AR. On rhinoscopy, vigorous PA was significantly associated with watery rhinorrhea (OR = 2.203, p = 0.048) but not pale mucosa. Total immunoglobulin E (IgE) and three allergen-specific IgE were not significantly elevated in participants who performed PA. Therefore, regular vigorous PA is associated with subjective and objective aggravation of AR symptoms, which may not necessarily manifest as increased serum IgE levels.

Diet: A Specific Part of the Western Lifestyle Pack in the Asthma Epidemic

The Western lifestyle is a complex concept that includes the diet as the main axis of different factors which contribute to a detrimental effect on health, lower life expectancy and low quality-of-life. This type of diet is characterized by being high in calories, mainly provided by saturated fats, and rich in sugars that can lead to changes in immune cells and their responsiveness, by different mechanisms that have yet to be totally clarified. Inflammatory processes are perpetuated through different pathways, in which adipose tissue is a major factor. High fat stores in overweight and obesity accumulate energy but the endocrine function is also producing and releasing different bioactive compounds, adipokines, known to be pro-inflammatory and which play an important role in the pathogenesis of asthma. This review therefore explores the latest evidence regarding the adverse effect of the Western diet on adipose tissue inflammation and its causative effect on the asthma epidemic.

Dietary Habits in Children with Respiratory Allergies: A Single-Center Polish Pilot Study

BACKGROUND

The rising trend in allergic diseases has developed in parallel with the increasing prevalence of obesity, suggesting a possible association. The links between eating habits and allergies have not been sufficiently clarified.

AIM

To evaluate the nutritional status, eating habits, and risk factors of obesity and pulmonary function in children with allergic rhinitis.

MATERIALS AND METHODS

We evaluated 106 children with allergic rhinitis (mean age 12.1 ± 3.4 years; M/F 60/46) from the Department of Allergology. Clinical data were collected regarding allergies, physical activity, nutritional status (Bodystat), dietary habits (Food Frequency Questionnaire validated for the Polish population), skin prick test with aeroallergens (Allergopharma), and spirometry (Jaeger).

RESULTS

All children suffered from allergic rhinitis; among them, 43 (40.6%) presented symptoms of asthma. There were differences between children with only allergic rhinitis (AR group) and children with both rhinitis and asthma (AA group) in pulmonary function (forced expiratory volume in one second (FEV₁) 100 ± 11 vs. 92.1 ± 15.0; p < 0.05). A total of 84 children (79%) presented a normal body mass index (BMI) (10-97 percentile), 8 (7.5%) were underweight, and 14 (13.5%) were overweight or obese. There were no differences in body composition between the AR and AA groups. Incorrect eating habits were demonstrated by most of the children, e.g., consumption of three or fewer meals in a day (38%), sweets every day (44%), snacking between meals every day (80%), and eating meals less than 1 h before bedtime (47%). Compared to the AR group, the AA group was more likely to eat more meals a day (p = 0.04), snack more often (p = 0.04), and eat before sleeping (p = 0.005). Multiple regression analysis showed a significant association between high BMI and snacking between meals and low physical activity (adjusted R² = 0.97; p < 0.05).

CONCLUSIONS

The risk factors for obesity in children with allergies include snacking and low physical activity. Most children with respiratory allergies, especially those with asthma, reported incorrect eating habits such as snacking and eating before bedtime. A correlation between pulmonary function and body composition or dietary habits was not found.

Prevalence of Ever Self-Reported Asthma and Associated Factors among University Students in Iran: A Population-Based Study

Background:

Asthma is a chronic inflammatory airway disease with regressive episodic symptoms. This study aimed to assess the prevalence of asthma ever (lifetime prevalence of asthma) and the associated factors among newly entered students in public universities in Iran.

Methods:

This population-based cross-sectional study was part of the “Mental and Physical Health Assessment of University Students in Iran.” The target population included all newly admitted students (N = 151,671) in 74 public universities in 28 provinces (out of the 31 provinces) in Iran. STATA version 12 was used for calculating the descriptive statistics. Univariate and multivariate logistic regression models were employed to identify relationships between asthma and socioeconomic variables. The level of significance was set at 95% confidence interval.

Results:

Of a total of 79,277 participants, 55.23% (n = 43,785) and 44.77% (n = 35,492) were female and male, respectively. The prevalence of ever asthma among studied student was 1.89%. Of all the participants with asthma, 88.43% (85.49%–90.84%) were nonsmokers. More than 20% of the subjects were physically inactive. The respondents who revealed smoking >10 cigarettes/week were about 1.22 (1.036–1.437) times more likely to suffer from asthma disease (0.017), as compared with those who were not smoking.

Conclusions:

Our study provides valuable information about the prevalence of asthma ever symptoms among university students in Iran. In fact, the results of this study can fill information gaps concerning the affected groups in Iran, and even worldwide.

The Frequency of Fast Food Consumption in Relation to Wheeze and Asthma Among Adolescents in Gauteng and North West Provinces, South Africa

The prevalence of asthma and allergic diseases have been on the rise, especially in developing countries due to life-style changes. The study aimed to investigate the association between the frequency of fast food consumption with wheeze and asthma among adolescents. A previously validated self-completed questionnaire from the International Study of Asthma and Allergies in Childhood was used to collect information on demographics, socioeconomic status, house characteristics, adolescent respiratory health and diet. The prevalence of wheeze was 38.2% and of asthma was 16.37% among the adolescents. The results from the adjusted regression analyses indicated that eating fast foods three or more times per week was a statistically significant risk factor for wheeze (OR = 1.60; 95% CI: 1.26–2.03) and asthma (OR = 1.37; 95% CI: 1.04–1.91). The study found an association between eating fast foods three or more times per week and wheeze and asthma among adolescents in South Africa. Unhealthy diet plays a crucial role in respiratory health among adolescents; healthy eating habits are encouraged to reduce the burden of respiratory symptoms and diseases.

Dietary patterns and asthma among Peruvian children and adolescents

BACKGROUND

Asthma is one of the conditions that contributes to the global burden of respiratory diseases and has been previously associated with diet intake. The goal of this study was to determine the relationship between diet, assessed by a developed score, and asthma in Peruvian children.

METHODS

This study was a cross sectional analysis nested within an unmatched case-control study of children in two peri-urban communities of Lima, Peru. We evaluated 767 children and adolescents (573 with asthma, 194 controls) between 9 and 19 years. Diet was assessed using a food frequency questionnaire (FFQ), with food groups classified as "healthy" or "unhealthy". Asthma control, Lung function and atopy were assessed by Asthma Control Test, Spirometry and InmunoCAP 250 test, respectively.

RESULTS

Mean age of participants was 13.8 years (SD 2.6). Mean diet score was 5 (SD 1.23; range 2-8). Healthy Diet Score was associated with asthma status [OR 0.83, 95% CI (0.72, 0.95), p = 0.009] in adjusted analysis. Thus, participants with higher HDS, had lower odds of asthma. In sensitivity analyses, when adjusting for atopy, results did not change significantly. [OR 0.85, 95% CI (0.72, 0.99); p = 0.04]. No association between the HDS and asthma control, FEV1, nor FeNO were observed. Atopy did not modify the association between diet and asthma outcomes.

CONCLUSIONS

In our study cohort, better diet quality was associated with lower odds of asthma, but was not associated with asthma control. Diet modification may be a potential intervention to impact the increasing prevalence of this disease.

Are Dietary Factors Associated with Lung Function in Canadian Adults?

Purpose: The purpose of this study was to explore the impact of dietary factors and biomarkers on lung function among Canadian adults (18-79 years). Methods: Our data source was the Canadian Health Measures Survey Cycle-3, which included 3397 adults. The household and clinic questionnaires and physical measures were used to assess individual dietary factors, modified Mediterranean Diet Scores, and biomarkers. Results: The overall mean percent predicted values for FVC and FEV₁ were 97% and 95%, respectively. While somewhat inconsistent between outcomes, higher lung function was associated with bean, grain, milk, fruit, and vegetable consumption, whereas lower lung function was associated with egg and potato consumption. Among the biomarkers, vitamin D, chloride, total serum protein, and red blood cell folate were associated with higher lung function, whereas C-reactive protein and vitamin B₁₂ was associated with lower lung function. Conclusion: Our study provides support for an association between some dietary factors and lung function, though not entirely consistent between a specific dietary factor and the outcomes studied (FVC, FEV₁, FVC/FEV₁, and FEF_25%-75%). The associations between a specific biomarker and lung function were more consistent (i.e., observed with a larger number of lung function outcomes) than were the dietary factors.

EAACI position paper on diet diversity in pregnancy, infancy and childhood: Novel concepts and implications for studies in allergy and asthma

To fully understand the role of diet diversity on allergy outcomes and to set standards for conducting research in this field, the European Academy of Allergy and Clinical Immunology Task Force on Diet and Immunomodulation has systematically explored the association between diet diversity and allergy outcomes. In addition, a detailed narrative review of information on diet quality and diet patterns as they pertain to allergic outcomes is presented. Overall, we recommend that infants of any risk category for allergic disease should have a diverse diet, given no evidence of harm and some potential association of benefit in the prevention of particular allergic outcomes. In order to harmonize methods for future data collection and reporting, the task force members propose relevant definitions and important factors for consideration, when measuring diet diversity in the context of allergy. Consensus was achieved on practice points through the Delphi method. It is hoped that the definitions and considerations described herein will also enable better comparison of future studies and improve mechanistic studies and pathway analysis to understand how diet diversity modulates allergic outcomes.

Rice Intake and Emerging Concerns on Arsenic in Rice: a Review of the Human Evidence and Methodologic Challenges

PURPOSE OF REVIEW

Rice is a major staple food worldwide and a dietary source of arsenic. We therefore summarized the state of the epidemiologic evidence on whether rice consumption relates to health outcomes associated with arsenic exposure.

RECENT FINDINGS

While epidemiologic studies have reported that higher rice consumption may increase the risk of certain chronic conditions, i.e., type 2 diabetes, most did not consider specific constituents of rice or other sources of arsenic exposure. Studies that examined rice intake stratified by water concentrations of arsenic found evidence of increasing trends in cardiovascular disease risk, skin lesions, and squamous cell skin cancers and bladder cancer associated with higher rice consumption. Further studies are needed to understand the health impacts of arsenic exposure from rice consumption taking into account all sources of rice intake and potential confounding by other dietary constituents or contaminants and arsenic exposure from sources such as water.

Relative validation of the adapted Mediterranean Diet Score for Adolescents by comparison with nutritional biomarkers and nutrient and food intakes: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

OBJECTIVE

To investigate whether adherence to the adapted Mediterranean Diet Score for Adolescents (MDS_A) and the adapted Mediterranean Diet Quality Index for Adolescents (KIDMED_A) is associated with better food/nutrient intakes and nutritional biomarkers.

DESIGN

The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study is a cross-sectional study aiming to obtain comparable data on a variety of nutritional and health-related parameters in European adolescents aged 12·5-17·5 years.

SETTING

Nine European countries.

PARTICIPANTS

European adolescents (n 2330) recruited to the HELENA study. Dietary intake was obtained with 24 h dietary recalls, an FFQ and a Food Choices and Preferences questionnaire. MDS_A was calculated as a categorical variable using cut-offs (MDS_A), as a continuous variable (zMDS_A) and with energy adjustments (zEnMDS_A). The KIDMED_A score was also calculated.

RESULTS

Multilevel linear regression analysis showed positive associations for zMDS_A and KIDMED_A with serum levels of vitamin D, vitamin C, plasma folate, holo-transcobalamin, β-carotene and n-3 fatty acids, while negative associations were observed with trans-fatty acid serum levels. For categorical indices, blood biomarkers showed few significant results. zMDS_A and KIDMED_A showed positive associations with vegetables and fruits intake, and negative associations with energy-dense and low-nutritious foods. zMDS_A and KIDMED_A were positively associated with all macronutrients, vitamins and minerals (all P < 0·0001), except with monosaccharides and PUFA for KIDMED_A and cholesterol for both indices (P < 0·05).

CONCLUSIONS

zMDS_A and KIDMED_A have shown the strongest associations with the dietary indicators and biomarkers that have been associated with the Mediterranean diet before, and are therefore considered the most appropriate and valid Mediterranean diet scores for European adolescents.

Mediterranean diet during pregnancy and childhood for asthma in children: A systematic review and meta-analysis of observational studies

OBJECTIVES

To evaluate the relationship between high adherence to the Mediterranean diet in pregnancy and childhood and the risk of asthma and wheeze in children.

METHODS

We conducted searches of PubMed, EMBASE, and Cochrane Central Register of Controlled Trials from inception to 30 October 2018. Observational studies providing risk estimates and corresponding confidence intervals on the association of high adherence to the Mediterranean diet in pregnancy or childhood and the risk of asthma or wheeze in childhood were included. The methodological quality of all included studies was assessed. Summary odds ratios (OR) were calculated using a random-effects model.

RESULTS

Eighteen observational studies were included in this review. All studies were of moderate to high quality. The pooled data suggested high adherence to the Mediterranean diet during pregnancy was associated with a reduced incidence of wheeze in the first 12 months (OR, 0.92; 95% confidence interval [CI], 0.88-0.95; P < 0.001), and there was an inverse association between the Mediterranean diet during childhood and the incidence of wheeze in the history (OR, 0.51; 95% CI, 0.37-0.70; P = 0.001) and current wheeze (OR, 0.97; 95% CI, 0.95-0.99; P = 0.013). However, there was no significant association between high adherence of the Mediterranean diet in pregnancy and childhood and any of the other meta-analysis end points including diagnosed asthma.

CONCLUSION

High adherence to the Mediterranean diet during pregnancy and childhood may have short-term effects on wheeze in children in early life. However, these findings should be interpreted with caution owing to the heterogeneity of the studies.

Adherence to the Mediterranean diet and inflammatory markers in children with asthma

INTRODUCTION

There is accumulated evidence supporting a beneficial role of Mediterranean diet (MD) in the control of asthma symptoms. The aim of this study was to investigate the relationships between adherence to MD and serum levels of certain cytokines namely, interleukin (IL)-4, and IL-17 known to have a pathogenetic role in the airway changes associated with asthma.

METHODS

We measured serum IL-4, IL-33, and IL-17, in 44 asthmatic and 26 healthy children, 5-15 years old. Their adherence to MD was estimated with the Mediterranean Diet Quality Index for children and adolescents (KIDMED) score.

RESULTS

KIDMED score did not differ between the two groups (P=0.59) and was not correlated with any of the three measured cytokines. However, when the analysis was restricted only to asthmatic children, the KIDMED score was correlated with IL-4, IL-33, and IL-17 (Beta: -0.56, P=0.007; Beta: 0.57, P=0.010; Beta: -0.62, P=0.017, respectively).

CONCLUSION

Our results indicate that MD can modulate the production of some of the main inflammatory mediators of asthma, in asthmatic children.

Prenatal Diet and the Development of Childhood Allergic Diseases: Food for Thought

PURPOSE OF REVIEW

The development of allergic disease is shaped by genetics and the environment, including diet. Many studies suggest a role for maternal diet during pregnancy. In this article, we discuss potential mechanisms by which specific nutrients, particular foods, and dietary patterns may influence allergic disease development and review studies examining the relationship between prenatal diet and the risk of childhood allergy.

RECENT FINDINGS

The combination of in utero exposures and genetic predisposition may contribute to the development of allergic disease by altering immune and organ development. Inflammation predominates in the first and third trimesters whereas the second trimester is characterized by anti-inflammatory and Th2 immune responses. Maternal dietary exposures during pregnancy may interact with inherited genetic risk factors influence immune system development. There are varied results regarding the impact of maternal prenatal diet on the development of childhood allergies. Well-designed randomized controlled studies are needed to clarify this area.

Is the consumption of fast foods associated with asthma or other allergic diseases?

The associations between the consumption of fast foods and asthma or allergic diseases have not been clarified. The aim of this study was to determine whether fast foods consumption is associated with asthma or allergic diseases. Databases were searched up to February 2018. Studies investigating the associations between fast foods consumption and asthma or allergic diseases were considered eligible. Included studies were assessed for quality using standardized critical appraisal checklists. The quality scores were 5.33 ± 1.16 in case-control studies and 5.69 ± 1.55 in cross-sectional studies. Adjusted odds ratios (aOR) with 95% confidence interval (CI) were pooled. Sixteen studies (13 cross-sectional and 3 case-control studies) were included. The consumption of fast foods was significantly related to current asthma (aOR: 1.58; 95% CI: 1.17-2.13 for case-control study and aOR: 1.58; 95% CI: 1.10-2.26 for cross-sectional studies), severe asthma (aOR: 1.34; 95% CI: 1.23-1.46), asthma ever (aOR: 1.36; 95% CI: 1.06-1.75), current wheeze (aOR: 1.21; 95% CI: 1.16-1.27), wheeze ever (aOR: 1.65; 95% CI: 1.07-2.52), physician-diagnosed allergic rhinitis (odds ratio: 1.43; 95% CI: 1.05-1.95), severe eczema (aOR: 1.51; 95% CI: 1.16-1.96) and severe rhino-conjunctivitis (aOR: 1.54; 95% CI: 1.18-2.00). The consumption of hamburgers was associated with current asthma (aOR: 1.59; 95% CI: 1.13-2.25), severe asthma (aOR: 1.34; 95% CI: 1.23-1.46), asthma ever (aOR: 1.47; 95% CI: 1.13-1.92), severe eczema (aOR: 1.51; 95% CI: 1.16-1.96), severe rhino-conjunctivitis (aOR: 1.54; 95% CI: 1.18-2.00) and rhino-conjunctivitis (aOR: 1.21; 95% CI: 1.15-1.27). The consumption of fast foods, especially hamburgers, ≥3 times/week, was more likely to be associated with severe asthma and current wheeze compared with the consumption of 1-2 times/week (both P < 0.001). In conclusion, the consumption of fast foods, particularly hamburgers, correlates to asthma in a dose-response pattern, which needs to be further validated in longitudinal and interventional studies.

An international comparison of risk factors between two regions with distinct differences in asthma prevalence

BACKGROUND AND PURPOSE

Investigation of the geographic variation in asthma prevalence can improve our understanding of asthma etiology and management. The purpose of our investigation was to compare the prevalence of asthma and wheeze among adolescents living in two distinct international regions and to investigate reasons for observed differences.

METHODS

A cross-sectional survey of 13-14 year olds was completed in Saskatoon, Canada (n=1200) and Skopje, Republic of Macedonia (n=3026), as part of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase 3 study. Surveys were self-completed by students following the ISAAC protocol. Multiple logistic regression models were used to investigate associations with reports of asthma and current wheeze. A mediation analysis was then completed.

RESULTS

Asthma prevalence was much higher in Saskatoon than Skopje (21.3% vs. 1.7%) as was the prevalence of current wheeze (28.2% vs. 8.8%). Higher paracetamol (acetaminophen) use was a consistent risk factor for asthma and wheeze in both locations and showed dose-response relationships. In both countries, paracetamol use and physical activity mediated some of the association for both asthma and wheeze. In Saskatoon, among those with current wheeze, 42.6% reported ever having a diagnosis of asthma compared to 10.2% among Skopje adolescents.

CONCLUSIONS

The results suggest that the variation in risk factors between the two locations may explain some of the differences in the prevalence of asthma and wheeze between these two study sites. However, diagnostic labeling patterns should not be ruled out as another potential explanatory factor.

Influence of the Mediterranean diet during pregnancy in the development of wheezing and eczema in infants in Pamplona, Spain

BACKGROUND

This study examined the relationship between different food groups and the adherence to a Mediterranean diet during pregnancy and the risk of wheezing and eczema in children aged 12-15 months.

METHODS

The study involves 1087 Spanish infants from the International Study of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL). The study of the association of the different food consumption and Mediterranean diet with wheezing, recurrent wheezing and eczema was performed using different models of unconditional logistic regression to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

No association was found between a good adherence to the Mediterranean diet during pregnancy and the development of wheezing (p=0.372), recurrent wheezing (p=0.118) and eczema (p=0.315). The consumption once or twice a week of white fish (OR: 1.95[1.01-3.75]), cooked potatoes (OR: 1.75[1.22-2.51]) and industrial pastry (OR: 1.59[1.13-2.24]), and the consumption more than three times a week of industrial pastry (OR: 1.47 [1.01-2.13]) during pregnancy increases the risk of "wheezing" at 12 months. Instead, high fruit consumption during the pregnancy has a protective effect against "wheezing" in 12-month-old infants (OR: 0.44 [0.20-0.99]). No statistically significant differences were observed between food intake during pregnancy and "recurrent wheezing". No statistically significant differences were observed between the consumption of any food during pregnancy and the presence of eczema at 12 months.

CONCLUSIONS

The present study showed that the consumption of Mediterranean diet during pregnancy did not have a protective effect for wheezing, recurrent wheezing or eczema.

Diet and Asthma: Is It Time to Adapt Our Message?

Asthma is a chronic respiratory disorder which is associated with airway inflammation. Environmental factors, in association with genetic susceptibility, play a critical role in asthma pathophysiology. Inhaled allergens, smoke exposure, indoor and outdoor air pollution are common triggers of asthma symptoms. Although the role of diet has clearly established mechanisms in diseases such as cardiovascular disease, type 2 diabetes, and cancer, it is not commonly identified as a causal factor in asthma. However, some dietary patterns, such as the Western diet, which includes a high intake of refined grains, processed and red meats, and desserts, have pro-inflammatory effects. On the contrary, the Mediterranean diet, with high intake of fruits and vegetables has anti-inflammatory properties. The influence of food on asthma outcomes is of growing interest, but dietary habits of asthma patients are not commonly investigated in clinical practice. In this review, we focus on the impact of diet on asthma risk and asthma control. We also detail the influence of diet on obese patients with asthma.

Does adherence to the Mediterranean dietary pattern reduce asthma symptoms in children? A systematic review of observational studies

OBJECTIVE

The purpose of the present systematic review was to synthesize evidence from the literature to assess efficacy of the Mediterranean dietary pattern in childhood asthma. Design/Setting A systematic search of six databases, three clinical trial registries and hand-search of peer-reviewed articles was conducted up to 29 October 2016. Inclusion criteria included exposure to a Mediterranean dietary pattern, measurement of asthma symptoms and study population of children aged <18 years. Quality assessment was conducted. Due to significant heterogeneity, meta-analysis was not feasible.

RESULTS

Of the 436 articles identified, after removal of duplicates and based on inclusion criteria, fifteen observational studies conducted in Mediterranean and non-Mediterranean countries were relevant. No randomized controlled trials were retrieved. Twelve studies reported an inverse association between adherence to a Mediterranean dietary pattern and asthma in children, two studies showed no association and one study showed an increase in asthma symptoms. In fourteen out of fifteen studies, quality assessment checks revealed good reliability and validity among study methodologies.

CONCLUSIONS

The current systematic review revealed a consistent inverse relationship (protective) between a Mediterranean dietary pattern and asthma in children. Future well-designed randomized controlled trials are needed to provide solid evidence. Nevertheless, the existing level of evidence adds to the public health message relating to the beneficial effects of a Mediterranean-type diet in children suffering with asthma.

Dietary patterns and the risk of obesity, type 2 diabetes mellitus, cardiovascular diseases, asthma, and neurodegenerative diseases

Diet and lifestyle play a significant role in the development chronic diseases; however the full complexity of this relationship is not yet understood. Dietary pattern investigation, which reflects the complexity of dietary intake, has emerged as an alternative and complementary approach for examining the association between diet and chronic diseases. Literature on this association has largely focused on individual nutrients, with conflicting outcomes, but individuals consume a combination of foods from many groups that form dietary patterns. Our objective was to systematically review the current findings on the effects of dietary patterns on chronic diseases. In this review, we describe and discuss the relationships between dietary patterns, such as the Mediterranean, the Dietary Approach to Stop Hypertension, Prudent, Seventh-day Adventists, and Western, with risk of obesity, type-2 diabetes mellitus, cardiovascular diseases, asthma, and neurodegenearive diseases. Evidence is increasing from both observational and clinical studies that plant-based dietary patterns, which are rich in fruits, vegetables, and whole grains, are valuable in preventing various chronic diseases, whereas a diet high in red and processed meat, refined grains and added sugar seems to increase said risk. Dietary pattern analysis might be especially valuable to the development and evaluation of food-based dietary guidelines.

Time-Dependent Associations Between Body Composition, Physical Activity, and Current Asthma in Women: A Marginal Structural Modeling Analysis

The role of obesity in adult asthma is well-known and has been partly attributed to a confounding role of physical inactivity. However, the interrelationships between obesity, physical activity, and asthma have been incompletely addressed, probably because their time-dependent and bidirectional nature represents a methodologically challenging research question. We aimed to estimate the independent causal effects of body mass index (BMI; weight (kg)/height (m)2) and physical activity on current asthma using marginal structural models (MSMs). MSMs were applied to 15,353 adult women from a 2011 case-control study of asthma (Asthma-E3N) nested within the French E3N study (Etude Epidémiologique auprès de Femmes de la Mutuelle Générale de l'Education Nationale). Three time periods (1997-2000-2002, 2000-2002-2005, and 2002-2005-2011) were defined, where exposures (BMI and physical activity) were measured at time t, outcome (current asthma) was measured at time t + 1, and covariates were measured at time t - 1 or at baseline. A strong significant and positive dose-response relationship between BMI and current asthma was observed (odds ratios were 0.90 (95% confidence interval (CI): 0.79, 1.03), 1.29 (95% CI: 1.17, 1.42), and 1.87 (95% CI: 1.60, 2.18) for the BMI groups <20.0, 25.0-29.9, and ≥30.0, respectively, versus the normal-weight group (BMI 20.0-24.9)). We found no association between physical activity and current asthma. Our results suggest an independent causal deleterious effect of overweight and obesity on current asthma, whereas no independent causal effect of physical activity was found.

The influence of gender and atopy in the relationship between obesity and asthma in childhood

BACKGROUND

The objective of the study was to examine the relationship between asthma and overweight-obesity in Spanish children and adolescents and to determine whether this relationship was affected by gender and atopy.

METHODS

The study involves 8607 Spanish children and adolescents from the International Study of Asthma and Allergies in Childhood phase III. Unconditional logistic regression was used to obtain adjusted odds ratios (OR) and 95% confidence intervals (95% CI) for the association between asthma symptoms and overweight-obesity in the two groups. Afterwards, it was stratified by sex and rhinoconjunctivitis.

RESULTS

The prevalence of overweight and obesity in 6-7-year-old children was 18.6% and 5.2% respectively and in 13-14 year-old teenagers was 11.4% and 1.1% respectively. Only the obese children, not the overweight children, of the 6-7 year old group had a higher risk of any asthma symptoms (wheezing ever: OR 1.68 [1.15-2.47], asthma ever: OR 2.29 [1.43-3.68], current asthma 2.56 [1.54-4.28], severe asthma 3.18 [1.50-6.73], exercise-induced asthma 2.71 [1.45-5.05]). The obese girls had an increased risk of suffering any asthma symptoms (wheezing ever: OR 1.73 [1.05-2.91], asthma ever: OR 3.12 [1.67-5.82], current asthma 3.20 [1.65-6.19], severe asthma 4.83[1.94-12.04], exercise-induced asthma 3.68 [1.67-8.08]). The obese children without rhinoconjunctivitis had a higher risk of asthma symptoms.

CONCLUSIONS

Obesity and asthma symptoms were associated in 6-7 year-old children but not in 13-14 year-old teenagers. The association was stronger in non-atopic children and obese girls.

Adherence to the Mediterranean Diet in children and adolescents: A systematic review

BACKGROUND AND AIM

A decreased adherence to the Mediterranean Diet (MD) may be related to a rise in chronic non-communicable diseases from childhood onward. The aim of this systematic review was to summarize the available literature regarding MD adherence in children and adolescents, and focusing, more specifically, on the association of MD adherence with demographic and anthropometric variables, body composition, lifestyle, and diet adequacy.

METHODS AND RESULTS

A search of scientific literature was carried out on PUBMED, SCOPUS, Clinical Trials Results, Google Scholar, and British Library Inside for studies published in the last 20 years. Fifty-eight papers were finally included according to the following criteria: MD adherence evaluated through a quantifying score or index, age 2-20 years, sample size >200 participants, observational or intervention studies regarding the general population. The KIDMED index was the most widely used scoring system. MD adherence widely varied within the Mediterranean countries for both children and adolescents, with also large differences among various European countries, while few data are available for non-Mediterranean countries. Most of the eligible studies showed that MD adherence was directly associated with physical activity (and possibly with diet adequacy) and inversely with sedentary behavior, while the results for gender, age, socioeconomic status and weight status were not consistent.

CONCLUSIONS

Further validation of MD indexes in terms of reproducibility and consistency with the MD is needed. At the same time, more prospective cohort and intervention studies may better elucidate the relationships of MD adherence with behavioral and health outcomes.

Effects of Fruit and Vegetable Consumption on Risk of Asthma, Wheezing and Immune Responses: A Systematic Review and Meta-Analysis

Evidence suggests that reduced intake of fruit and vegetables may play a critical role in the development of asthma and allergies. The present review aimed to summarize the evidence for the association between fruit and vegetable intake, risk of asthma/wheeze and immune responses. Databases including PubMed, Cochrane, CINAHL and EMBASE were searched up to June 2016. Studies that investigated the effects of fruit and vegetable intake on risk of asthma/wheeze and immune responses were considered eligible (n = 58). Studies used cross-sectional (n = 30), cohort (n = 13), case-control (n = 8) and experimental (n = 7) designs. Most of the studies (n = 30) reported beneficial associations of fruit and vegetable consumption with risk of asthma and/or respiratory function, while eight studies found no significant relationship. Some studies (n = 20) reported mixed results, as they found a negative association between fruit only or vegetable only, and asthma. In addition, the meta-analyses in both adults and children showed inverse associations between fruit intake and risk of prevalent wheeze and asthma severity (p < 0.05). Likewise, vegetable intake was negatively associated with risk of prevalent asthma (p < 0.05). Seven studies examined immune responses in relation to fruit and vegetable intake in asthma, with n = 6 showing a protective effect against either systemic or airway inflammation. Fruit and vegetable consumption appears to be protective against asthma.

Dietary total antioxidant capacity in early school age and subsequent allergic disease

Background

Dietary antioxidant intake has been hypothesized to influence the development of allergic diseases; however, few prospective studies have investigated this association.

Objective

Our aim was to study the association between total antioxidant capacity (TAC) of the diet at age 8 years and the subsequent development of asthma, rhinitis and sensitization to inhalant allergens between 8 and 16 years, and to assess potential effect modification by known risk factors.

Methods

A total of 2359 children from the Swedish birth cohort BAMSE were included. Dietary TAC at age 8 years was estimated by combining information on the child's diet the past 12 months from a food frequency questionnaire with a database of common foods analysed with the oxygen radical absorbance capacity method. Classification of asthma and rhinitis was based on questionnaires, and serum IgE antibodies were measured at 8 and 16 years.

Results

A statistically significant inverse association was observed between TAC of the diet and incident sensitization to inhalant allergens (adjusted odds ratio: 0.73, 95% confidence interval: 0.55–0.97 for the third compared to the first tertile, P‐value for trend = 0.031). Effect modification by traffic‐related air pollution exposure was observed, with a stronger association between dietary TAC and sensitization among children with low traffic‐related air pollution exposure (P‐value for interaction = 0.029). There was no evidence for effect modification by GSTP1 or TNF genotypes, although these results should be interpreted with caution. No clear associations were observed between TAC and development of rhinitis or asthma, although a significant inverse association was observed for allergic asthma (OR_adj 0.57, 95% CI 0.34–0.94).

Conclusions and Clinical Relevance

Higher TAC of the diet in early school age may decrease the risk of developing sensitization to inhalant allergens from childhood to adolescence. These findings indicate that implementing an antioxidant‐rich diet in childhood may contribute to the prevention of allergic disease.

Dietary intake is associated with respiratory health outcomes and DNA methylation in children with asthma

BACKGROUND

Asthma is an increasingly common chronic disease among children, and data point toward a complex mechanism involving genetic, environmental and epigenetic factors. Epigenetic modifications such as DNA hypo- or hyper-methylation have been shown to occur in response to environmental exposures including dietary nutrients.

METHODS

Within the context of the asthma randomized trial of indoor wood smoke (ARTIS) study, we investigated relationships between diet, asthma health measures, and DNA methylation. Asthma health measures included a quality of life instrument, diurnal peak flow variability (dPFV) and forced expiratory volume in the first second (FEV₁). Dietary intake was assessed with a food frequency questionnaire. Methylation levels of LINE-1 repetitive element and two promoter CpG sites for interferon gamma (IFNγ, -186 and -54) from buccal cell DNA were measured using pyrosequencing assays.

RESULTS

Data were collected on 32 children with asthma living in western Montana who were recruited to the ARTIS study. Selenium and several methyl donor dietary nutrients were positively associated with the asthma quality of life measure. Intake of methyl donating nutrients including folate was positively associated LINE-1 methylation and negatively associated with IFNγ CpG-186. Higher levels of LINE-1 methylation were associated with greater dPFV.

CONCLUSION

We identified several nutrients that were associated with improved quality of life measures among children with asthma. The IFNγ promoter CpG site -186 but not -54 was associated with the intake of selected dietary nutrients. However, in this small population of children with asthma, the IFNγ promoter CpG sites were not associated with respiratory health measures so it remains unclear through which epigenetic mechanism these nutrients are impacting the quality of life measure. These findings add to the evidence that dietary nutrients, particularly foods containing methyl donors, may be important for epigenetic regulation as it pertains to the control of asthma. Trial registration ClincialTrials.gov NCT00807183. Registered 10 December 2008.