Diet and asthma: an update

Dietary choline intake and its association with asthma: A study based on the National Health and Nutrition Examination Survey database

OBJECTIVE

This work endeavored to examine the correlation between dietary choline intake and the odds of asthma, utilizing data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

Aggregated data from seven cycles (2005-2018) in the NHANES database were utilized. The independent variable was dietary choline intake, and the dependent variable was asthma. The weighted logistic regression method was used to construct a model reflecting the relationship between these two factors. This work employed stratified analysis without adjusting for confounding factors and subgroup analysis with adjusted confounding factors to mine the association between dietary choline intake and asthma. Additionally, restricted cubic spline analysis examined nonlinear associations of the two in age subgroups.

RESULTS

Forty five thousand and seven hundreds ninety seven samples were included here. The model indicating the relationship between dietary choline intake and asthma was constructed (OR: 0.86, 95% CI: 0.79-0.93, p < 0.001). Stratified analysis indicated that the interaction terms of age (p < 0.001) and body mass index (BMI) (p = 0.002) with dietary choline intake significantly influenced the relationship model. In the adjusted models, accounting for demographic characteristics, poverty impact ratio, BMI, exposure to environmental tobacco smoke, and total energy intake, an increase in dietary choline intake significantly reduced the odds of asthma (OR: 0.79, 95% CI: 0.72-0.88, p < 0.001). Subgroup analyses based on age and BMI revealed a significant negative correlation between dietary choline intake and the odds of asthma in the adult population (OR: 0.76, 95% CI: 0.67-0.86, p < 0.001), as well as in individuals with a BMI between 25 and 30 kg/m2 (OR: 0.79, 95% CI: 0.63-0.99, p = 0.042), and those with a BMI >30 kg/m2 (OR: 0.73, 95% CI: 0.60-0.89, p = 0.002).

CONCLUSION

Dietary choline intake was significantly inversely correlated with asthma prevalence, especially in adults and overweight/obese individuals, suggesting that increasing choline intake may reduce asthma risk. Further research is needed to explore this relationship and provide tailored dietary recommendations for different age and BMI groups to enhance asthma prevention and management.

Evaluation of Healthy Eating Index and Children's Diet Inflammatory Index according to asthma severity group

BACKGROUND

Diet may contribute to better asthma control in children by impacting the immune and inflammatory pathophysiology. Therefore, this study aimed to investigate differences in nutrient intake, Children's Dietary Inflammatory Index (C-DII), and dietary quality according to asthma severity.

MATERIALS AND METHODS

Asthma severity, dietary inflammatory status, and diet quality were assessed in a sample of 202 children with asthma (55.6% males, aged 5-18 years) attending a pediatric allergy outpatient clinic. Asthma severity was evaluated according to the Global Initiative for Asthma criteria and categorized as mild, moderate, or severe. The Children's Dietary Inflammatory Index (C-DII) and Healthy Eating Index (HEI-2010) were calculated based on information collected by the 24-h dietary recall method. Dietary quality was categorized as poor, moderate, or good diet according to HEI-2010.

RESULTS

The mean age of the participants was 9.6 ± 3.2 years. Children with severe asthma were younger on average (p < 0.05). Children with mild asthma had significantly higher fiber and iron intake than those with moderate asthma (p < 0.05). C-DII values did not differ significantly according to asthma severity (p > 0.05). Dietary quality was evaluated as moderate in 89.1% of the participants and also showed no difference based on asthma severity.

CONCLUSIONS

These findings suggest that inflammatory status and diet quality may not affect asthma severity in children, highlighting the influence of various genetic and environmental factors on the association between diet and asthma severity. More comprehensive and longitudinal studies are needed to investigate the mechanisms linking diet and asthma.

Association of body mass index with asthma occurrence and persistence in adolescents: A retrospective study of NHANES (2011-2018)

Objective

To investigate the association of body mass index (BMI) with asthma and analyze the risk factors of asthma persistence among overweight/obese adolescents and those with a high risk for obesity.

Methods

In this cross-sectional study, adolescents aged 11-17 years with complete general information and asthma diagnoses were selected from the National Health and Nutrition Examination Survey database. For adolescents without self-reported asthma, we performed matching according to age and sex at a case-to-control ratio of 1:3. Logistic regression analysis was employed to identify independent predictors of asthma occurrence followed by constructing a nomogram and comparing its efficacy to independent factors in predicting asthma occurrence. Besides, associations of BMI with asthma occurrence and persistence were evaluated. Finally, we obtained risk factors for asthma persistence in overweight/obese individuals and those at a high risk for obesity.

Results

Totally 753 adolescents with asthma and 2259 adolescents without asthma were included to analyze the occurrence of asthma. BMI and Hispanic Ethnicity were independent predictors of asthma occurrence and were included in nomogram construction. BMI had an efficiency comparable to that of the nomogram model in predicting asthma occurrence, which is superior to that of Hispanic Ethnicity. Of the 753 adolescents diagnosed with asthma, 464 were still diagnosed with asthma of at least a year's duration. Interestingly, BMI may have the ability to predict asthma persistence. Further, Hispanic Ethnicity and household income were significantly related to asthma occurrence among overweight/obese and high-risk obese individuals.

Conclusions

High BMI could independently predict increased asthma occurrence. Additionally, BMI may play an essential role in predicting asthma persistence. This study may help improve the diagnosis and reduce the occurrence of asthma.

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.

The Relationship Between General and Abdominal Obesity, Nutrition and Respiratory Functions in Adult Asthmatics

Objective: Although obesity is known to have adverse effects on asthma, it is not fully known whether general or abdominal obesity affects asthma symptoms more. In this study, the effects of diet and general/abdominal obesity on respiratory functions were evaluated.Methods: A total of 204 adult asthmatic individuals participated in the study. Anthropometric measurements, respiratory functions, asthma control test (ACT) scores, and 24-hour food consumption were recorded. The results were compared according to body mass index (BMI), waist circumference (WC), and waist-hip ratio (WHR) classification.Results: FEV₁, FVC, MEF_25-75, MEF₅₀, and MEF₂₅ decreased with the increase in BMI, WC, and WHR. FEV₁ showed a negative linear relationship with BMI, WC and WHR and these results were more significant in WC and WHR than BMI. Similarly, the ACT score also showed a negative correlation with BMI (r = -0.372; p = 0.023), WC (r = -0.402; p = 0.001) and WHR (r = -0.387; p = 0.011), and the results were more significant in WC and WHR than BMI. Individuals whose WC (OR: 2.170 CI (1.325-3.182)) and WHR (OR: 2.119 CI (1.246-3.338)) were at risk had higher odds of uncontrolled asthma than those with normal WC and WHR. Each 100-kcal increase in total energy consumption increased the odds of uncontrolled asthma (OR: 1.125 CI (1.086-2.217)) (p < 0.05).Conclusions: The effects of WC and WHR, which are indicators of abdominal obesity, on respiratory functions and ACT score were found to be higher than BMI. Obese individuals should be referred to diet clinics to improve their asthma symptoms.

Micronutrients and the Risk of Allergic Diseases in School Children

Microelements and vitamins are believed to have immunomodulatory effects. The aim of the study was to establish the role of antioxidants (vitamins A, E, D) and microelements such as copper (Cu), selenium (Se), and zinc (Zn) levels in allergic diseases in schoolchildren. The study uses a cohort of 80 children (40 with and 40 without allergy/asthma diagnosis) aged 9 to 12 years recruited for the Polish Mother and Child Cohort Study. At nine to twelve years old, the children were tested for microelement and vitamin content and health status (including skin-prick test and spirometry, urine cotinine level). Demographic data were collected from mothers by an allergist. The risk of asthma occurrence was found to be significantly related to the levels of Cu and Zn. The level of Cu was also particularly closely associated with allergic rhinitis and was indicated as a significant predictor of food allergy. The levels of Cu and Zn, and poor nutritional status in general, can influence the immune system and may be considered risk factors for developing asthma, allergic rhinitis and food allergy.

Mediterranean-Type Diets as a Protective Factor for Asthma and Atopy

We are currently riding the second wave of the allergy epidemic, which is ongoing in affluent societies, but now also affecting developing countries. This increase in the prevalence of atopy/asthma in the Western world has coincided with a rapid improvement in living conditions and radical changes in lifestyle, suggesting that this upward trend in allergic manifestations may be associated with cultural and environmental factors. Diet is a prominent environmental exposure that has undergone major changes, with a substantial increase in the consumption of processed foods, all across the globe. On this basis, the potential effects of dietary habits on atopy and asthma have been researched rigorously, but even with a considerable body of evidence, clear associations are far from established. Many factors converge to obscure the potential relationship, including methodological, pathophysiological and cultural differences. To date, the most commonly researched, and highly promising, candidate for exerting a protective effect is the so-called Mediterranean diet (MedDi). This dietary pattern has been the subject of investigation since the mid twentieth century, and the evidence regarding its beneficial health effects is overwhelming, although data on a correlation between MedDi and the incidence and severity of asthma and atopy are inconclusive. As the prevalence of asthma appears to be lower in some Mediterranean populations, it can be speculated that the MedDi dietary pattern could indeed have a place in a preventive strategy for asthma/atopy. This is a review of the current evidence of the associations between the constituents of the MedDi and asthma/atopy, with emphasis on the pathophysiological links between MedDi and disease outcomes and the research pitfalls and methodological caveats which may hinder identification of causality. MedDi, as a dietary pattern, rather than short-term supplementation or excessive focus on single nutrient effects, may be a rational option for preventive intervention against atopy and asthma.

The Dietary Inflammatory Index and asthma burden in children: A latent class analysis

INTRODUCTION

Unbalanced dietary intake has been increasingly recognized as an important modifiable risk factor for asthma. In this study, we assessed whether a pro-inflammatory diet is associated with higher asthma burden in three steps: (1) identification of asthma latent classes (LC) based on symptoms, indoor exposures, and pulmonary function; (2) identification of risk factors associated with LC membership; and (3) estimation of the probabilities of LC membership with variation in DII.

METHODS

A cross-sectional study on 415 children aged 5-14 years (266 with persistent asthma and 149 controls). LC analysis was performed in asthmatic children. The DII was calculated based on a semiquantitative food frequency questionnaire. Elastic net logistic regression was used to investigate whether increasing DII was associated with worse asthma burden.

RESULTS

Two LCs were identified. Children in Class 1, "high burden," had higher symptom burden and worse lung function. Children in Class 2, "low burden," had lower symptom burden and less impaired lung function but were more subject to indoor exposures. DII was the only risk factor significantly associated with Class 1 membership. As the DII increased (from -4.0 to +4.0), the probability of Class 1 membership increased from 32% to 65% when compared with control group, whereas it increased from 41% to 72% when compared with Class 2.

CONCLUSIONS

We identified two phenotypes of persistent asthma associated with different disease burden linked to indoor exposures. An increasing DII was associated with high-burden asthma, providing further evidence about the role of a pro-inflammatory diet in asthma morbidity.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

Dietary Patterns, Asthma, and Lung Function in the Hispanic Community Health Study/Study of Latinos

Rationale: Dietary patterns may alter immune responses and increase asthma risk or affect lung function.Objectives: To examine whether a proinflammatory diet (assessed by the energy-adjusted Dietary Inflammatory Index [E-DII]) or high dietary quality (assessed by the Alternative Healthy Eating Index [AHEI-2010]) are associated with current asthma, current asthma symptoms, and lung function in Hispanic adults.Methods: This was a cross-sectional study of 12,687 adults aged 18 to 76 years who participated in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). The E-DII and AHEI-2010 were calculated based on two 24-hour dietary recalls. Logistic or linear regression was used for the multivariable analysis of E-DII or AHEI-2010 scores and current asthma, asthma symptoms, and lung function measures, adjusting for age, sex, annual household income, study center, Hispanic/Latino background, smoking status, and other covariates.Results: A higher E-DII score was associated with current asthma (odds ratio [OR] for quartile 4 vs. 1, 1.35; 95% confidence interval [CI], 0.97-1.90) and asthma symptoms (OR for quartile 4 vs. 1, 1.42; 95% CI, 1.12-1.81). The AHEI-2010 score was not associated with current asthma or asthma symptoms. Among adults without asthma, a higher E-DII score was associated with lower forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC), and a higher AHEI-2010 score was associated with higher FEV₁ and FVC.Conclusions: Our findings suggest that a proinflammatory diet increases the risk of asthma and asthma symptoms in Hispanic adults. An antiinflammatory diet (indicated by a lower E-DII or a higher AHEI-2010 score) may positively influence lung function in Hispanic adults without asthma.

Nutritional Interventions to Improve Asthma-Related Outcomes through Immunomodulation: A Systematic Review

Asthma is a chronic inflammatory disease of the airways, characterized by T-helper (Th) 2 inflammation. Current lifestyle recommendations for asthma patients are to consume a diet high in fruits and vegetables and to maintain a healthy weight. This raises the question of whether other nutritional interventions may also improve asthma-related outcomes and whether these changes occur via immunomodulation. Therefore, we systematically reviewed studies that reported both asthma-related outcomes as well as immunological parameters and searched for relations between these two domains. A systematic search identified 808 studies, of which 28 studies met the inclusion criteria. These studies were divided over six nutritional clusters: herbs, herbal mixtures and extracts (N = 6); supplements (N = 4); weight loss (N = 3); vitamin D3 (N = 5); omega-3 long-chain polyunsaturated fatty acids (LCPUFAs) (N = 5); and whole-food approaches (N = 5). Fifteen studies reported improvements in either asthma-related outcomes or immunological parameters, of which eight studies reported simultaneous improvements in both domains. Two studies reported worsening in either asthma-related outcomes or immunological parameters, of which one study reported a worsening in both domains. Promising interventions used herbs, herbal mixtures or extracts, and omega-3 LCPUFAs, although limited interventions resulted in clinically relevant results. Future studies should focus on further optimizing the beneficial effects of nutritional interventions in asthma patients, e.g., by considering the phenotypes and endotypes of asthma.

Longitudinal Association Between Diet Quality and Asthma Symptoms in Early Adult Life in a Brazilian Birth Cohort

Background

The role of diet in the etiology of asthma is still inconclusive. This paper evaluated the longitudinal association between diet quality and chest wheezing in young adults.

Methods

This is a longitudinal study with follow-up information from 18- and 22-year-olds (18y and 22y) of the 1993 Pelotas (Brazil) Birth Cohort. Chest wheezing occurrence and number of events in the last year were reported at 22y. Diet quality was measured with a revised version of the Healthy Eating Index (IQD-R) for the Brazilian population at 18y and 22y by food frequency questionnaire referring to the last 12 months. The diet quality continuity was classified as good (always 1st IQD-R tertile), intermediate (always 2nd tertile/change tertile) and poor (always 3rd tertile).

Results

A total of 2986 young individuals were evaluated; 51.4% were female. Prevalence of wheezing at 22y was 10.1% (95% CI: 9.1–11.2), and of these patients, 10% reported at least one event in the past year. Better IQD-R score, both at 18y and at 22y, the lower the odds of wheezing in the past year. Regarding the diet quality continuity from 18y to 22y, staying on a poor diet increased by more than three-fold the odds of chest wheezing (OR=3.28; 95% CI: 1.84–5.84) and of wheezing events (OR=3.32; 95% CI: 1.89–5.85) compared to staying on a good diet, after adjustment for confounding variables.

Conclusion

The overall quality of the diet seems to be more important than the individual components in the effect on asthma symptoms. Low-quality diet persistence increased the odds of chest wheezing and the number of events.

Lipid mediators and asthma: Scope of therapeutics

Lipids and their mediators are known to play a pro-inflammatory role in several human diseases including asthma. The influence of leukotrienes and prostaglandins through arachidonate metabolism in asthma pathophysiology is well established and hence, prompted the way for therapeutic strategies targeting lipid metabolites. In addition, various types of fatty acids have been reported to play a diverse role in asthma. For instance, CD4⁺ T-lymphocytes differentiation towards T-effector (T_eff) or T-regulatory (Tregs) cells seems to be controlled reciprocally by fatty acid metabolic pathways. Further, the dysregulated lipid status in obesity complicates the asthma manifestations suggesting the role of lipid metabolites particularly ω-6 fatty acids in the process. On the other hand, clinical and pre-clinical studies suggests the role of short chain fatty acids in curbing asthma through upregulation of T-regulatory cells or clearance of inflammatory cells through promoting apoptosis. Accordingly, the present review compiles various studies for comprehensive analysis of different types of lipid based metabolites in asthma manifestation. Finally, we have proposed certain strategies which may enhance the usefulness of lipid mediators for balanced immune response during asthma.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

[Asthma and obesity in adults]

Asthma is a chronic inflammatory airway disorder characterized by a multitude of phenotypes. Epidemiological studies show an increase in asthma prevalence in obese patients regardless of age. The association of asthma and obesity is now considered as a phenotype with its own clinical, biological and functional characteristics. Regarding the pathophysiology of asthma and obesity, numerous factors such as nutrition, genetic predisposition, microbiome, ventilatory mechanics and the role of adipose tissue have been identified to explain the heterogeneous characteristics of patients with asthma and obesity. In adult patients with asthma and obesity, respiratory symptoms are particularly prominent and atopy and eosinophilic inflammation is uncommon compared to normal weight asthma patients. Obese asthma patients experience more hospitalizations and use more rescue medications than normal weight asthmatics. Management of asthma in obese patients is complex because these patients have less response to the usual anti-asthmatic treatments. Weight loss through caloric restriction combined with exercise is the main intervention to obtain improvement of asthma outcomes. Bariatric surgery is an invasive procedure with interesting results.

Vitamin D plasma concentration and vitamin D receptor genetic variants confer risk of asthma: A comparison study of Taiwanese and Mongolian populations

Background

Recent reports have suggested that lower vitamin D serum levels are associated with susceptibility to and severity of asthma in different white populations, which may be due to a lack of sunlight exposure, genetic polymorphism of vitamin D pathway genes, and dietary intake. We investigated the associations between vitamin D concentration, genetic polymorphism of the vitamin D receptor (VDR), and asthma traits in Mongolian and Taiwanese populations that inhabited two different geographical areas.

Methods

In total, 328 Han Taiwanese subjects and 381 Mongolian subjects were enrolled, and their vitamin D serum levels assayed. Genomic DNA of 178 Han Taiwanese subjects and 90 Mongolian subjects was obtained from blood samples. Single-nucleotide polymorphisms (SNPs) of VDR, ApaI (rs7975232), TaqI (rs731236), BsmI (rs1544410) and FokI (rs2228570), were selected for genotyping. Logistic regression analyses were performed to detect an association between allergic asthma status and the interaction of the VDR SNP and serum vitamin D concentration in the case–control samples.

Results

We observed a significantly lower vitamin D level in the Mongolian subjects as compared with the Taiwanese population. In particular, in the population under 14 years of age, the serum vitamin D level was significantly higher in the Taiwanese population, in both non-asthmatic and asthmatic subjects, than in the Mongolian non-asthmatic and asthmatic subjects, respectively (P < 0.01). Moreover, the vitamin D level in the asthmatic children was significantly lower than that in the non-asthmatic children in both the Taiwanese and Mongolian populations (P < 0.01, respectively). Furthermore, we found that the rs2228570 genotype (OR, 3.763) of the VDR SNP and the vitamin D concentration (lower than 40 ng/ml, OR: 38.938) both contribute to increased susceptibility to bronchial asthma.

Conclusion

Our results demonstrated an association between vitamin D concentration and the risk of asthma in two populations of differing ethnicity living in different geographical areas. This information implies a potential role of vitamin D in the prevention and treatment of asthma worldwide.

Nutrient intake is a predictor of lung function in obese asthmatic adolescents undergoing interdisciplinary therapy

Asthma-obesity is a multifactorial disease with specific asthma phenotypes that aggravate due to overweight and an unbalanced diet. Furthermore, obese asthmatic patients are corticotherapy-resistant. Therefore, the aims of the present study were to evaluate the effects of an interdisciplinary intervention on food consumption, body composition, lung function and adipokines in asthmatic and non-asthmatic obese adolescents and to investigate the influence of nutrients on lung function. Obese non-asthmatic (n 42) and obese asthmatic (n 21) adolescents of both sexes were enrolled in the present study. Food intake, adipokine levels, body composition, asthma symptoms and lung function were assessed across the study. After the intervention of 1 year, there was a reduction (P ≤ 0·01) in BMI, body fat percentage, visceral and subcutaneous fat and an increase (P ≤ 0·01) in lean mass and all lung function variables in both groups, except the relation between forced expiratory volume in 1 s and forced vital capacity (FEV1:FVC) in non-asthmatic patients. Moreover, both groups decreased lipid and cholesterol consumption (P ≤ 0·01). The highest energy consumption (β = -0·021) was associated with lower values of FVC. Similarly, carbohydrate consumption (β = -0·06) and cholesterol were negative predictors (β = -0·05) in FEV1:FVC. However, the consumption of Ca (β = 0·01), fibres (β = 1·34) and vitamin A (β = 0·01) were positive predictors of FEV1:FVC. Asthma-obesity interdisciplinary treatment promoted an improvement on food consumption and lung function in adolescents and demonstrated that the consumption of nutrients influenced an increase in lung function.

Asthma and Dietary Intake of Fish, Seaweeds, and Fatty Acids in Korean Adults

The dietary intake of fish and fatty acid may influence the risk of asthma, yet epidemiological research remains controversial and inconclusive. We examined the association between asthma and the dietary intake of fish, seaweeds, and fat in a Korean population, aged 19 to 64 years, using the data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2013-2016 (n = 13,038). The prevalence of doctor-diagnosed asthma and medication prescribed asthma were 2.5% and 1.0%, respectively. The subjects with medication prescribed asthma had significantly lower consumption of seaweeds (p = 0.0110) and lower n3/n6 polyunsaturated fatty acid (PUFA) (p = 0.0275) as compared to subjects without medication prescribed asthma. Multiple logistic regression analysis showed that the odds ratio (OR) (95% confidence interval, CI) of doctor-diagnosed asthma in the highest quartile were 0.63 (0.41-0.97) and 0.66 (0.44-1.00) for fish and seaweeds respectively, compared to the lowest quartile after adjusting confounding factors. Furthermore, there were significant inverse associations between medication prescribed asthma and seaweeds [OR (95% CI) = 0.37 (0.19-0.70)], n-3 PUFA [OR (95% CI) = 0.43 (0.21-0.89)] and n3/n6 [OR (95% CI) = 0.47 (0.22-0.99)] intake after adjusting for confounding factors. These results suggest, that the higher consumption of fish and seaweed and the high ratio of n-3 to n-6 PUFA may be associated with a lower prevalence of asthma.

Household food insecurity is associated with asthma control in Peruvian children living in a resource-poor setting

Rationale: Prior evidence suggests that there may be an association between asthma and food insecurity. We sought to describe the prevalence of food insecurity access, defined as having sufficient resources for appropriate foods in Lima, Peru, and evaluate its association with asthma status and control.Methods: We analyzed data from 553 children with asthma and 268 healthy controls aged nine to 19 years living in two peri-urban communities in Lima, Peru, in 2013. We used the Household Food Insecurity Access Scale to assess food insecurity. We defined uncontrolled asthma as an asthma control test score ≤19. We used multivariable logistic regressions to determine the relationship between asthma outcomes and food insecurity adjusting for age, sex, socioeconomic status, body mass index, and setting.Results: Average age was 14.2 years (SD 2.7). There was a high prevalence of household food insecurity in our study: 330 participants (40.2%) were food insecure, and average food insecurity access score was 2.7 points (SD 4.2). While being food insecure was not associated with asthma status (OR = 1.23, 95% CI 0.85 to 1.79; p = 0.28), it was associated with a higher odds of having uncontrolled asthma (OR = 2.01, 95% CI 1.13 to 3.59; p = 0.02). Each one-unit increase in food insecurity score (higher scores indicating more insecurity) was associated with 8% higher odds of having uncontrolled asthma (OR = 1.08, 95% CI 1.02 to 1.14; p < 0.01).Conclusions: Worse asthma control was associated with food insecurity. Future studies are needed to better understand the role of food security in determining the success of treatment strategies.

Vitamin A and D intake in pregnancy, infant supplementation, and asthma development: the Norwegian Mother and Child Cohort

Background

Western diets may provide excess vitamin A, which is potentially toxic and could adversely affect respiratory health and counteract benefits from vitamin D.

Objective

The aim of this study was to examine child asthma at age 7 y in relation to maternal intake of vitamins A and D during pregnancy, infant supplementation with these vitamins, and their potential interaction.

Design

We studied 61,676 school-age children (born during 2002-2007) from the Norwegian Mother and Child Cohort with data on maternal total (food and supplement) nutrient intake in pregnancy (food-frequency questionnaire validated against biomarkers) and infant supplement use at age 6 mo (n = 54,142 children). Linkage with the Norwegian Prescription Database enabled near-complete follow-up (end of second quarter in 2015) for dispensed medications to classify asthma. We used log-binomial regression to calculate adjusted RRs (aRRs) for asthma with 95% CIs.

Results

Asthma increased according to maternal intake of total vitamin A [retinol activity equivalents (RAEs)] in the highest (≥2031 RAEs/d) compared with the lowest (≤779 RAEs/d) quintile (aRR: 1.21; 95% CI: 1.05, 1.40) and decreased for total vitamin D in the highest (≥13.6 µg/d) compared with the lowest (≤3.5 µg/d) quintile (aRR: 0.81; 95% CI: 0.67, 0.97) during pregnancy. No association was observed for maternal intake in the highest quintiles of both nutrients (aRR: 0.99; 95% CI: 0.83, 1.18) and infant supplementation with vitamin D or cod liver oil.

Conclusions

Excess vitamin A (≥2.5 times the recommended intake) during pregnancy was associated with increased risk, whereas vitamin D intake close to recommendations was associated with a reduced risk of asthma in school-age children. No association for high intakes of both nutrients suggests antagonistic effects of vitamins A and D. This trial was registered at http://www.clinicaltrials.gov as NCT03197233.

[Role of non pharmacological Interventions for asthma]

Smoking cessation remains a major issue for asthmatic smokers. Respiratory rehabilitation and respiratory physiotherapy have shown a benefit in controlling symptoms, preventing exacerbations and improving the quality of life. The control of the environment is crucial and must be approached in a global way. Management of obesity and psychological disorders should be systematically proposed. Allergen immunotherapy may be discussed in allergic persistent asthma to house dust mites. Certain dietary interventions or alternative medicines have not proved their worth.

Health risk behaviors, violence exposure, and current asthma among adolescents in the United States

BACKGROUND

Asthma may worsen during adolescence, due to both health risk behaviors and psychosocial stressors commonly encountered during this life stage.

METHODS

Cross-sectional study of 24 612 high school students who participated in the 2009 and 2011 National Youth Risk Behavior Survey. Multivariable logistic regression was used to examine the relation between self-reported health risk behaviors or psychosocial stressors and current asthma. Mediation analysis was performed to assess whether depressive symptoms or suicidal behavior contribute to the link between psychosocial stressors and asthma.

RESULTS

Current asthma was reported by 13.1% of the study participants. In a multivariable analysis, female sex, obesity, shorter sleep duration, frequent soda/pop consumption, and marijuana use were each significantly associated with 14-36% increased odds of asthma. Any violent behavior (adjusted odds ratio [OR] = 1.12, 95% confidence interval [CI] = 1.02-1.24), any victimization (OR = 1.43, 95%CI = 1.29-1.58), any suicidal behavior (OR = 1.41, 95%CI = 1.22-1.64) and having felt sad or hopeless in the past year (OR = 1.57, 95%CI = 1.40-1.75) were each associated with current asthma. In a mediation analyses, having felt sad/hopeless and suicidal behaviors accounted for 21% and 14%, respectively, of the victimization-asthma association.

CONCLUSION

Potentially modifiable risk factors, including obesity, short sleep duration, frequent soda/pop consumption, and psychosocial stressors are associated with asthma in US adolescents. Promoting healthier lifestyles, as well as screening for violence exposure and treating depressive symptoms, could help reduce asthma burden in this population.

Oligo-fucoidan improved unbalance the Th1/Th2 and Treg/Th17 ratios in asthmatic patients: An ex vivo study

An imbalance in the helper T cells (Th)1/Th2 and regulatory T cells (Tregs)/Th17 ratios is believed to play a key role in asthmatic inflammatory responses. Fucoidan reportedly reduces the production of inflammatory factors. Nutritional intervention is an important tool in decreasing the severity of asthmatic disease. This study aimed to investigate the beneficial roles of oligo-fucoidan in balancing the T cell subtype ratios and reducing airway inflammation ex vivo. Peripheral blood mononuclear cells (PBMCs) were collected from 30 asthmatic subjects and 15 healthy subjects. Harvested PBMCs were stimulated and treated with or without oligo-fucoidan (100 or 500 µg/ml) for 48 h. Cell surface and intracellular cytokine markers were examined by flow cytometry. The pro-inflammatory factors in plasma and culture supernatants were measured using ELISA kits. We found that oligo-fucoidan increases the proportion of Th1 and Treg cells, but did not affect the proportion of Th2 and Th17 cells. Oligo-fucoidan also increased the levels of interferon-γ and interleukin-10. Thus, we concluded that oligo-fucoidan might improve the imbalance in Th1/Th2 and Treg/Th17 ratios to reduce airway inflammation, which could be a potential adjuvant therapy for allergic asthma.

The Dietary Inflammatory Index and Current Wheeze Among Children and Adults in the United States

BACKGROUND

A proinflammatory diet may increase allergic airway inflammation by affecting innate and adaptive immune responses.

OBJECTIVE

In this study, we examine the relation between the diet's inflammatory potential, measured by the Dietary Inflammatory Index (DII), and current asthma, current wheeze, and lung function in U.S. children and adults.

METHODS

We analyzed data from 8,175 children (aged 6-17 years) and 22,294 adults (aged 18-79 years) who participated in the 2007-2012 National Health and Nutrition Examination Survey. The DII was calculated by nutrient intake based on 24-hour dietary recalls, and normalized as per 1,000 calories of food consumed to account for total energy intake. Multivariable regression models were used for the analysis of the DII and current asthma, current wheeze, and lung function measures.

RESULTS

Higher DII (a proinflammatory diet) was associated with current wheeze among adults (eg, odds ratio [OR] for quartile 4 vs 1, OR = 1.41, 95% confidence interval [CI] = 1.17-1.70; Ptrend < .01) and among children with high fractional exhaled nitric oxide (a marker of eosinophilic airway inflammation; OR = 2.38, 95% CI = 1.13-5.02; Ptrend = .05). The DII also was associated with decreased forced expiratory volume in 1 second and forced vital capacity in adults without asthma or wheezing. The DII was not associated with lung function in children or current asthma in either age group.

CONCLUSIONS

Our findings suggest that a proinflammatory diet, assessed by the DII, increases the odds of current wheeze in adults and children with allergic (atopic) wheeze. These results further support testing dietary interventions as part of the management of asthma.

Prenatal and Early Life Fructose, Fructose-Containing Beverages, and Midchildhood Asthma

RATIONALE

Cross-sectional studies have linked intake of high-fructose corn syrup-sweetened beverages with asthma in schoolchildren.

OBJECTIVES

To examine associations of maternal prenatal and early childhood intake of sugar-sweetened beverages and fructose with current asthma in midchildhood (median age, 7.7 yr).

METHODS

We assessed maternal pregnancy (first- and second-trimester average) and child (median age, 3.3 yr) intake of sugar-sweetened beverages and total fructose using food frequency questionnaires in 1,068 mother-child pairs from Project Viva, a prospective prebirth cohort. In a multivariable analysis, we examined associations of quartiles of maternal and child sugar-sweetened beverage, juice, and total fructose intake with child current asthma in midchildhood, assessed by questionnaire as ever having doctor-diagnosed asthma plus taking asthma medications or reporting wheezing in the past 12 months.

RESULTS

Higher maternal pregnancy sugar-sweetened beverage consumption (mean, 0.6 servings/d; range, 0-5) was associated with younger maternal age, nonwhite race/ethnicity, lower education and income, and higher prepregnancy body mass index. Adjusting for prepregnancy body mass index and other covariates, comparing quartile 4 with quartile 1, higher maternal pregnancy intake of sugar-sweetened beverages (odds ratio, 1.70; 95% confidence interval, 1.08-2.67) and total fructose (odds ratio, 1.58; 95% confidence interval, 0.98-2.53) were associated with greater odds of midchildhood current asthma (prevalence, 19%). Higher early childhood fructose intake (quartile 4 vs. quartile 1) was also associated with midchildhood current asthma in models adjusted for maternal sugar-sweetened beverages (odds ratio, 1.79; 95% confidence interval, 1.07-2.97) and after additional adjustment for midchildhood body mass index z-score (odds ratio, 1.77; 95% confidence interval, 1.06-2.95).

CONCLUSIONS

Higher sugar-sweetened beverage and fructose intake during pregnancy and in early childhood was associated with childhood asthma development independent of adiposity.

Diet, Lung Function, and Asthma Exacerbations in Puerto Rican Children

Changes in dietary patterns may partly explain the epidemic of asthma in industrialized countries. The objective of this study was to examine the relationship between dietary patterns and lung function and asthma exacerbations in Puerto Rican children. This is a case-control study of 678 Puerto Rican children (ages 6-14 years) in San Juan (Puerto Rico). All participants completed a respiratory health questionnaire and a 75-item food frequency questionnaire. Food items were aggregated into 7 groups: fruits, vegetables, grains, protein, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group and asthma. Based on the results, a dietary score was created [range from -2 (unhealthy diet: high consumption of dairy and sweets, low consumption of vegetables and grains) to 2 (healthy diet: high consumption of vegetables and grains and low consumption of dairy and sweet)]. Multivariable linear or logistic regression was used to assess the relationship between dietary score and lung function or asthma exacerbations. After adjustment for covariates, a healthier diet (each 1-point increment in dietary score) was associated with significantly higher %predicted forced expiratory volume in the first second (FEV₁) and %predicted forced vital capacity (FVC) in control subjects. Dietary pattern alone was not associated with asthma exacerbations, but children with an unhealthy diet and vitamin D insufficiency (plasma 25(OH)D <30 ng/mL) had higher odds of ≥1 severe asthma exacerbation [odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.5-7.5] or ≥1 hospitalization due to asthma (OR = 3.9, 95% CI = 1.6-9.8, OR = 3.4, 95% CI = 1.5-7.5) than children who ate a healthy diet and were vitamin D sufficient. A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with higher lung function (as measured by FEV₁ and FVC). Vitamin D insufficiency, together with an unhealthy diet, may have detrimental effects on asthma exacerbations in children.

Prenatal exposures and the development of childhood wheezing illnesses

PURPOSE OF REVIEW

To critically evaluate and summarize studies published between July 2015 and June 2016 linking prenatal exposures and the onset of childhood wheezing illnesses and to discuss future research directions in this field.

RECENT FINDINGS

The aggregated evidence indicates a consistent detrimental effect of prenatal exposure to parental smoking, outdoor air pollution, and maternal stress on childhood wheezing illnesses. Less consistent evidence suggests an adverse impact of maternal obesity during pregnancy and prenatal exposure to antibiotics on these outcomes. There is insufficient evidence to support an association between in-utero exposure to acetaminophen or prenatal levels of specific nutrients (such as vitamin D, folic acid, or polyunsaturated fatty acids) and childhood wheezing illnesses.

SUMMARY

Several common potentially modifiable prenatal exposures appear to be consistently associated with childhood wheezing illnesses (e.g. parental smoking, outdoor air pollution, and maternal stress). However, the effect of many other prenatal exposures on the onset of childhood wheezing illnesses remains unclear. The existing scientific evidence from the past year does not allow us to make any new recommendations on primary prevention measures. Intervention studies will best demonstrate whether changing the prenatal environment can prevent childhood wheezing illnesses and asthma.

The Toxicological Mechanisms of Environmental Soot (Black Carbon) and Carbon Black: Focus on Oxidative Stress and Inflammatory Pathways

The environmental soot and carbon blacks (CBs) cause many diseases in humans, but their underlying mechanisms of toxicity are still poorly understood. Both are formed after the incomplete combustion of hydrocarbons but differ in their constituents and percent carbon contents. For the first time, “Sir Percival Pott” described soot as a carcinogen, which was subsequently confirmed by many others. The existing data suggest three main types of diseases due to soot and CB exposures: cancer, respiratory diseases, and cardiovascular dysfunctions. Experimental models revealed the involvement of oxidative stress, DNA methylation, formation of DNA adducts, and Aryl hydrocarbon receptor activation as the key mechanisms of soot- and CB-induced cancers. Metals including Si, Fe, Mn, Ti, and Co in soot also contribute in the reactive oxygen species (ROS)-mediated DNA damage. Mechanistically, ROS-induced DNA damage is further enhanced by eosinophils and neutrophils via halide (Cl⁻ and Br⁻) dependent DNA adducts formation. The activation of pulmonary dendritic cells, T helper type 2 cells, and mast cells is crucial mediators in the pathology of soot- or CB-induced respiratory disease. Polyunsaturated fatty acids (PUFAs) were also found to modulate T cells functions in respiratory diseases. Particularly, telomerase reverse transcriptase was found to play the critical role in soot- and CB-induced cardiovascular dysfunctions. In this review, we propose integrated mechanisms of soot- and CB-induced toxicity emphasizing the role of inflammatory mediators and oxidative stress. We also suggest use of antioxidants and PUFAs as protective strategies against soot- and CB-induced disorders.

Relationship between Oxidative Stress, Physical Activity, and Vitamin Intake in Patients with Asthma

BACKGROUND

Oxidative stress plays an important role in the pathogenesis of bronchial asthma. Antioxidant nutrition and supplementation have been used to reduce oxidative stress. However, a clinical trial with antioxidant supplementation showed no beneficial effects in patients with asthma. On the other hand, physical activity is related to the prognosis of chronic obstructive pulmonary disease (COPD) and is also related to oxidant status. We investigated the relationships between oxidative stress, serum levels of vitamins, dietary vitamin intake, daily activities, and pulmonary functions in patients with asthma.

METHODS

Eighteen patients with bronchial asthma were enrolled in this study. Reactive oxidative stress was assessed by measuring organic hydroperoxides (diacron reactive oxygen metabolites: dROM) in sera and by measuring H₂O₂ levels in exhaled breath condensates. The biological antioxidant capacity in serum was evaluated by measuring antioxidant potential capacity against ferric ion. We also assessed pulmonary functions, fraction of exhaled nitric oxide, serum levels of vitamins, dietary vitamin intake, and physical activities.

RESULTS

There were no relationships between the index of oxidative stress (dROM and H₂O₂ in exhaled breathe condensates) and pulmonary functions, serum levels of vitamins, daily vitamin intakes, and activity levels in patients with asthma.

CONCLUSION

The status of transient oxidative stress may not be related to daily activities, vitamin levels, and pulmonary functions in patients with asthma in a real-life setting. However, our results were obtained in the short-term period from a small number of subjects, so a large longitudinal study is required to ascertain the relationships between oxidative stress, physical activity and vitamin intake in patients with 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.