Early life events in asthma--diet

Maternal dietary indexes are not linked to early childhood wheezing or atopic eczema

BACKGROUND

Several recent studies have investigated the association between maternal diet during pregnancy and wheezing or asthma in children. However, whether a specific dietary pattern during pregnancy protects children from wheezing or atopic diseases remains unclear. This study investigated the association between The Alternative Healthy Eating Index for Pregnancy (AHEI-P), the Dietary Inflammatory Index (DII), and the risk for wheezing and atopic eczema in children during the first year of life.

METHODS

This study included 1330 mother-child pairs who attended the Kuopio Birth Cohort (KuBiCo) study and had dietary information during the last trimester and information on children's health in the first year of life. AHEI-P and DII indicate a healthy diet and dietary inflammation potential during pregnancy. The AHEI-P and DII were compared with reported wheezing and doctor-diagnosed atopic eczema in children during the first year of life.

RESULTS

Neither AHEI-P nor DII is associated with wheezing or atopic eczema in children when analyzed by continuous variables and by tertiles. The odds ratio (95% CI) for AHEI-P and wheezing was 0.99 (0.98-1.01), for AHEI-P and atopic eczema1.01 (0.99-1.02), for DII and wheezing 1.02 (0.95-1.09), and for DII and atopic eczema 0.97 (0.91-1.04).

CONCLUSION

In this cohort study, AHEI-P and DII during pregnancy were not associated with wheezing or atopic eczema in the offspring during the first year of life.

Maternal dietary patterns during pregnancy and the risk of infantile eczema during the first year of life: a cohort study in northeast China

BACKGROUND

There are few studies on the relationship between diet during pregnancy and infantile eczema and the conclusions are inconsistent. The aim of the present study was to explore the impact of dietary patterns during pregnancy on infantile eczema.

METHODS

A total of 495 mother-child pairs from a prospective cohort in Shenyang, China was recruited. Information on maternal dietary intake during pregnancy was assessed with a validated self-administered food frequency questionnaire. The data of infantile eczema was assessed using a structured questionnaire. Factor analysis to derive dietary patterns. The relationship between the dietary pattern and infantile eczema was examined by the logistic regression analysis.

RESULTS

The cumulative incidence of eczema in 6 months and 12 months in northeast China was 45.7% and 57.8%, respectively. Three dietary patterns were identified. There was a tendency for an expose-response relationship between the maternal high-protein dietary pattern during pregnancy and the risk of infantile eczema within 12 months (P for trend = 0.023): the adjusted odds ratio (95% confidence interval) in the Q1, Q2, Q3, Q4 were 1.00 (reference), 1.63 (0.96-2.76), 1.81 (1.06-3.06), and 1.87 (1.09-3.20), respectively. No association between Western and plant-based patterns during pregnancy and infantile eczema within 12 months was found. Infantile eczema within 6 months was not associated with any of the three dietary patterns.

CONCLUSION

The maternal high-protein pattern during pregnancy may be a risk factor for infantile eczema during the first year of life.

Maternal stress increases risk of allergic lung inflammation in adult mice

BACKGROUND

Allergies are increasing worldwide. The presence of atopic diseases in the mother propagates the onset of allergic diseases in the offspring with a considerably stronger penetrance than atopic diseases of the father. Such observation challenges genetic predispositions as the sole cause of allergic diseases. Epidemiological studies suggest that caregiver stress in the perinatal period may predispose offspring to asthma. Only one group has studied the link between prenatal stress and neonatal asthma susceptibility in a murine model.

OBJECTIVES

We aimed to study if the neonatal increased risk of developing allergic lung inflammation persists after puberty and if there are sex differences in susceptibility.

METHODS

Pregnant BALB/c mice were subjected to a single restraint stress exposure at day 15 of gestation. Pups were separated by gender and subjected to a well-known sub-optimal asthma model after puberty.

RESULTS

Adult mice born to stressed dams were more susceptible to developing allergic pulmonary inflammation since an increase in the number of eosinophils in bronchoalveolar lavage (BAL), a greater peribronchial and perivascular infiltrate, a higher proportion of mucus-producing cells, and increased IL-4 and IL-5 levels in BAL were detected compared to control mice. These effects were more profound in females than males. Moreover, only females from stressed dams showed an increase in IgE levels.

CONCLUSIONS

Increased litter susceptibility to develop allergic lung inflammation induced by maternal stress persists after puberty and is more potent in females than in male mice.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Asthma, allergy and vitamin E: Current and future perspectives

Asthma and allergic disease result from interactions of environmental exposures and genetics. Vitamin E is one environmental factor that can modify development of allergy early in life and modify responses to allergen after allergen sensitization. Seemingly varied outcomes from vitamin E are consistent with the differential functions of the isoforms of vitamin E. Mechanistic studies demonstrate that the vitamin E isoforms α-tocopherol and γ-tocopherol have opposite functions in regulation of allergic inflammation and development of allergic disease, with α-tocopherol having anti-inflammatory functions and γ-tocopherol having pro-inflammatory functions in allergy and asthma. Moreover, global differences in prevalence of asthma by country may be a result, at least in part, of differences in consumption of these two isoforms of tocopherols. It is critical in clinical and animal studies that measurements of the isoforms of tocopherols be determined in vehicles for the treatments, and in the plasma and/or tissues before and after intervention. As allergic inflammation is modifiable by tocopherol isoforms, differential regulation by tocopherol isoforms provide a foundation for development of interventions to improve lung function in disease and raise the possibility of early life dietary interventions to limit the development of lung disease.

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.

Fish consumption during pregnancy and risk of allergic diseases in the offspring: A systematic review and meta-analysis

Although several studies have reported the beneficial effects of maternal fish consumption on allergy diseases in the offspring, the findings are conflicting. We summarized earlier data on the association between maternal fish intake and risk of allergy diseases in the offspring through a meta-analysis. A systematic literature search of relevant reports published in Medline/PubMed, ISI web of Science, EMBASE, SCOPUS and Google Scholar prior to February 2020 was conducted. All observational studies (cross-sectional, case-control or cohort) that examined the relationship between intake of maternal fish and risk of allergy diseases in the offspring were considered. Duplicate and non-related studies were excluded. In total, 31 studies on maternal fish consumption and risk of allergic diseases in the offspring were included. Greater maternal fish intake was associated with a reduced risk of wheeze (Pooled effect size: 0.97; 95% CI: 0.96-0.99) and food allergy (0.75; 95% CI: 0.64-0.88). Maternal fish consumption was not associated with risk of asthma (pooled effect size: 0.99; 95% CI: 0.89, 1.11), eczema (pooled effect size: 0.93; 95% CI: 0.84, 1.03), allergic rhinitis (pooled effect size: 0.91; 95% CI: 0.75, 1.09), and inhalant allergy (pooled effect size: 0.86; 95% CI: 0.66, 1.13). In non-linear dose-response meta-analysis, increased intake of fish during pregnancy (at the level of 50 to 200 grams per week) was associated with a reduced risk of eczema (P non-linearity = 0.042). Meta-regression of included studies revealed an inverse linear association between maternal fish intake and risk of eczema; such that every additional 30-gram per week consumption of fish during pregnancy was associated with a 4% reduced risk of eczema. We found that fish intake during pregnancy was associated with a lower risk of wheeze, eczema and food allergy in children. No significant association was seen between maternal fish consumption and risk of offspring's asthma, allergic rhinitis, and inhalant allergy.

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.

Maternal dietary inflammatory potential and quality are associated with offspring asthma risk over 10-year follow-up: the Lifeways Cross-Generation Cohort Study

BACKGROUND

Asthma is the most common childhood chronic health condition. Maternal antenatal diet has been associated with offspring asthma risk, but studies investigating maternal whole diet quality and inflammatory potential with long-term offspring follow-up (>5 y) are rare.

OBJECTIVES

We aimed to elucidate these associations in a prospective cohort study in Ireland.

METHODS

Early pregnancy diets were assessed using a validated FFQ from which energy-adjusted Dietary Inflammatory Index (E-DII) and Healthy Eating Index (HEI)-2015 scores were computed. Doctor-diagnosed offspring asthma status (general practitioner or parent reports) for the first 10 y of life was collected at 3-y, 5-y, and 9-y follow-up. A total of 862 mother-child pairs with information on maternal diet and ≥1 offspring asthma data points were included. The longitudinal associations between maternal E-DII and HEI scores and offspring asthma status were assessed using generalized estimating equations.

RESULTS

Cumulative offspring asthma incidence was 21% over the 10-y period. In the main models, adjusted for maternal lifestyle and sociodemographic factors, a higher E-DII score, indicating a more proinflammatory diet, was associated with higher risk of offspring asthma (OR: 1.35; 95% CI: 1.10, 1.65; per 1-SD score increment), whereas a higher HEI-2015 score, indicating better dietary quality, was associated with lower risk (OR: 0.77; 95% CI: 0.64, 0.93) (both P < 0.01). Results persisted with further adjustment for childhood factors (e.g., breastfeeding, diet, and childcare attendance) and parental asthma history. Similar associations were observed when E-DII and HEI-2015 scores were modeled in quartiles (both P-trend < 0.05). Associations for HEI-2015 were attenuated after adjustment for E-DII, suggesting the importance of anti-inflammatory pathways.

CONCLUSIONS

Our results suggest that a proinflammatory and low-quality diet during pregnancy is associated with a higher risk of offspring asthma. Pending confirmation from other studies, optimizing these aspects of maternal diet can be a promising strategy for reducing childhood asthma risk. This prospective observational study was registered at the ISRCTN Registry as ISRCTN16537904.

PUFA status at birth and allergy-related phenotypes in childhood: a pooled analysis of the Maastricht Essential Fatty Acid Birth (MEFAB) and RHEA birth cohorts

Lower prenatal exposure to n-3 PUFA relative to n-6 PUFA has been hypothesised to influence allergy development, but evidence remains largely inconsistent. In the Dutch Maastricht Essential Fatty Acid Birth (MEFAB) (n 293) and Greek RHEA Mother-Child (n 213) cohorts, we investigated whether cord blood phospholipid PUFA concentrations are associated with symptoms of wheeze, asthma, rhinitis and eczema at the age of 6-7 years. Information on allergy-related phenotypes was collected using validated questionnaires. We estimated relative risks (RR) and 95 % CI for associations of PUFA with child outcomes using multivariable generalised linear regression models. In pooled analyses, higher concentration of the n-3 long-chain EPA and DHA and a higher total n-3:n-6 PUFA ratio were associated with lower risk of current wheeze (RR 0·61; 95 % CI 0·45, 0·82 per sd increase in EPA+DHA and 0·54; 95 % CI 0·39, 0·75 per unit increase in the n-3:n-6 ratio) and reduced asthma risk (RR 0·50; 95 % CI 0·31, 0·79 for EPA+DHA and 0·43; 95 % CI 0·26, 0·70 for the n-3:n-6 ratio). No associations were observed for other allergy-related phenotypes. The results were similar across cohorts. In conclusion, higher EPA and DHA concentrations and a higher n-3:n-6 fatty acid ratio at birth were associated with lower risk of child wheeze and asthma. Our findings suggest that dietary interventions resulting in a marked increase in the n-3:n-6 PUFA ratio, and mainly in n-3 long-chain PUFA intake in late gestation, may reduce the risk of asthma symptoms in mid-childhood.

Fish and seafood consumption during pregnancy and the risk of asthma and allergic rhinitis in childhood: a pooled analysis of 18 European and US birth cohorts

Background

It has been suggested that prenatal exposure to n-3 long-chain fatty acids protects against asthma and other allergy-related diseases later in childhood. The extent to which fish intake in pregnancy protects against child asthma and rhinitis symptoms remains unclear. We aimed to assess whether fish and seafood consumption in pregnancy is associated with childhood wheeze, asthma and allergic rhinitis.

Methods

We pooled individual data from 60 774 mother-child pairs participating in 18 European and US birth cohort studies. Information on wheeze, asthma and allergic rhinitis prevalence was collected using validated questionnaires. The time periods of interest were: infancy (0-2 years), preschool age (3-4 years), and school age (5-8 years). We used multivariable generalized models to assess associations of fish and seafood (other than fish) consumption during pregnancy with child respiratory outcomes in cohort-specific analyses, with subsequent random-effects meta-analyses.

Results

The median fish consumption during pregnancy ranged from 0.44 times/week in The Netherlands to 4.46 times/week in Spain. Maternal fish intake during pregnancy was not associated with offspring wheeze symptoms in any age group nor with the risk of child asthma [adjusted meta-analysis relative risk (RR) per 1-time/week = 1.01, 95% confidence interval 0.97-1.05)] and allergic rhinitis at school age (RR = 1.01, 0.99-1.03). These results were consistently found in further analyses by type of fish and seafood consumption and in sensitivity analyses.

Conclusion

We found no evidence supporting a protective association of fish and seafood consumption during pregnancy with offspring symptoms of wheeze, asthma and allergic rhinitis from infancy to mid childhood.

Serum carotenoid and tocopherol concentrations and risk of asthma in childhood: a nested case-control study

BACKGROUND

The antioxidant hypothesis regarding the risk of asthma in childhood has resulted in inconsistent findings. Some data indicate that the role of antioxidants in childhood asthma risk may have a critical time window of effect, but only a well-designed longitudinal cohort study can clarify this hypothesis.

OBJECTIVE

To study the longitudinal associations between serum carotenoid and tocopherol concentrations during the first 4 years of life and asthma risk by the age of 5 years.

METHODS

Based on a case-control design nested within a Finnish birth cohort, 146 asthma cases were matched to 270 controls on birth time, sex, genetic risk, and birth place. Non-fasting blood samples were collected at the ages of 1, 1.5, 2, 3, and 4 years and serum carotenoids and tocopherols were analysed. Parents reported the presence and age at start of persistent doctor-diagnosed asthma in the child at the age of 5 years. Data analyses were conducted using generalized estimating equations.

RESULTS

We did not find strong associations between serum carotenoids and tocopherols and the risk of asthma based on age-specific and longitudinal analyses. Both lower and higher quarters of α-carotene and γ-tocopherol increased the risk of asthma.

CONCLUSIONS

The current findings do not support the suggestion that the increased prevalence of asthma may be a consequence of decreased intake of antioxidant nutrients. Moreover, we did not confirm any critical time window of impact of antioxidants on asthma risk. Replication of these findings in similar longitudinal settings will strengthen this evidence base.

Diet Hypotheses in Light of the Microbiota Revolution: New Perspectives

From an evolutionary standpoint, allergy has only recently emerged as a significant health problem. Various hypotheses were proposed to explain this, but they all indicated the importance of rapid lifestyle changes, which occurred in industrialized countries in the last few decades. In this review, we discuss evidence from epidemiological and experimental studies that indicate changes in dietary habits may have played an important role in this phenomenon. Based on the example of dietary fiber, we discuss molecular mechanisms behind this and point towards the importance of diet-induced changes in the microbiota. Finally, we reason that future studies unraveling mechanisms governing these changes, along with the development of better tools to manipulate microbiota composition in individuals will be crucial for the design of novel strategies to combat numerous inflammatory disorders, including atopic diseases.

The influence of dietary immunomodulatory factors on development of food allergy in children

In the last few years many studies have been conducted on the role of dietary and environmental factors in the prevention of allergic diseases among children. Many studies have shown that the diet of pregnant women and children in their early postnatal life, rich in antioxidants, vitamin D, and fatty acids is beneficial as it reduces the risk of allergy in their future life. Moreover, there are many reports about the main role of gut microbiota and probiotics in the allergy prevention, what can indicate new ways of procedures in allergic diseases.

Vitamin D exposure during pregnancy, but not early childhood, is associated with risk of childhood wheezing

The association between vitamin D and wheezing in early childhood is unclear. The primary objective of this study was to evaluate the association between vitamin D exposure, during both pregnancy and childhood, and early childhood wheezing. Secondary objectives were to evaluate the associations between vitamin D exposures and asthma and wheezing severity. We conducted a cohort study of children (0-5 years) recruited from 2008 to 2013 through the TARGet Kids! primary-care research network. Vitamin D exposures included maternal vitamin D supplement use during pregnancy, child vitamin D supplementation and children's 25-hydroxyvitamin D (25(OH)D) concentrations. The outcomes measured were parent-reported childhood wheezing, diagnosed asthma and wheezing severity. Vitamin D supplement and wheezing data were available for 2478 children, and blood samples were available for 1275 children. Adjusted odds ratios (aOR) were estimated using logistic regression adjusted for age, sex, ethnicity, body mass index, birth weight, outdoor play, breastfeeding duration, daycare status, parental smoking and family history of asthma. Vitamin D supplementation during pregnancy was associated with lower odds of childhood wheezing (aOR=0.65; 95% CI: 0.46-0.93). In early childhood, neither 25(OH)D (aOR per 10 nmol/l=1.01; 95% CI: 0.96-1.06) nor vitamin D supplementation (aOR=1.00; 95% CI: 0.81-1.23) was associated with wheezing. No significant associations were observed with diagnosed asthma or wheezing severity. Vitamin D supplementation during pregnancy was associated with reduced odds of wheezing, but child vitamin D supplementation and childhood 25(OH)D were not associated with reduced wheezing. The timing of exposure may be important in understanding the association between vitamin D and childhood wheezing.

Vitamin D, allergies and asthma: focus on pediatric patients

In recent years, the interest of the scientific world towards vitamin D gradually increased, and several studies have been conducted to dissect its possible role in modulating the development/course of allergic diseases. Also, Vitamin D supplementation has been assessed as a beneficial approach for treating allergies in some, but not all studies. We reviewed herein the available and relevant literature concerning the possible links between Vitamin D, its supplementation and allergic diseases. A literature search was made independently by the Authors, identifying articles for a narrative review. As per literature, Vitamin D plays a key role in calcium and phosphate metabolism, and it is essential for bone health in infants, children and adolescents. However, there is presently insufficient evidence to support vitamin D supplementation for prevention or treatment of allergic diseases in infants, children and adolescents, concerning allergic rhinitis, asthma, food allergy and atopic dermatitis.

Vitamin E and D regulation of allergic asthma immunopathogenesis

Asthma occurs as complex interactions of the environmental and genetics. Clinical studies and animal models of asthma indicate dietary factors such as vitamin E and vitamin D as protective for asthma risk. In this review, we discuss opposing regulatory functions of tocopherol isoforms of vitamin E and regulatory functions of vitamin D in asthma and how the variation in global prevalence of asthma may be explained, at least in part, by these dietary components.

Epidemiology of Respiratory Allergies and Asthma

Asthma has puzzled and confused physicians from the time of Hippocrates to the present day. The word “asthma” comes from a Greek word meaning “panting” (Keeney 1964), but reference to asthma can also be found in ancient Egyptian, Hebrew, and Indian medical writings (Ellul-Micallef 1976; Unger and Harris 1974). There were clear observations of patients experiencing attacks of asthma in the second century and evidence of disordered anatomy in the lung as far back as the seventeenth century (Dring et al. 1689).

Culture of airway epithelial cells from neonates sampled within 48-hours of birth

INTRODUCTION

Little is known about how neonatal airway epithelial cell phenotype impacts on respiratory disease in later life. This study aimed to establish a methodology to culture and characterise neonatal nasal epithelial cells sampled from healthy, non-sedated infants within 48 hours of delivery.

METHODS

Nasal epithelial cells were sampled by brushing both nostrils with an interdental brush, grown to confluence and sub-cultured. Cultured cells were characterised morphologically by light and electron microscopy and by immunocytochemistry. As an exemplar pro-inflammatory chemokine, IL-8 concentrations were measured in supernatants from unstimulated monolayers and after exposure to IL-1β/TNF-α or house dust mite extract.

RESULTS

Primary cultures were successfully established in 135 (91%) of 149 neonatal samples seeded, with 79% (n  =  117) successfully cultured to passage 3. The epithelial lineage of the cells was confirmed by morphological analysis and immunostaining. Constitutive IL-8 secretion was observed and was upregulated by IL-1β/TNF-α or house dust mite extract in a dose dependent manner.

CONCLUSION

We describe a safe, minimally invasive method of culturing nasal epithelial cells from neonates suitable for functional cell analysis offering an opportunity to study "naïve" cells that may prove useful in elucidating the role of the epithelium in the early origins of asthma and/or allergic rhinitis.

Vitamin E isoforms as modulators of lung inflammation

Asthma and allergic diseases are complex conditions caused by a combination of genetic and environmental factors. Clinical studies suggest a number of protective dietary factors for asthma, including vitamin E. However, studies of vitamin E in allergy commonly result in seemingly conflicting outcomes. Recent work indicates that allergic inflammation is inhibited by supplementation with the purified natural vitamin E isoform α-tocopherol but elevated by the isoform γ-tocopherol when administered at physiological tissue concentrations. In this review, we discuss opposing regulatory effects of α-tocopherol and γ-tocopherol on allergic lung inflammation in clinical trials and in animal studies. A better understanding of the differential regulation of inflammation by isoforms of vitamin E provides a basis towards the design of clinical studies and diets that would effectively modulate inflammatory pathways in lung disease.

Two faces of vitamin E in the lung

Asthma and allergic lung disease occur as complex environmental and genetic interactions. Clinical studies of asthma indicate a number of protective dietary factors, such as vitamin E, on asthma risk. However, these studies have had seemingly conflicting outcomes. In this perspective, we discuss opposing regulatory effects of tocopherol isoforms of vitamin E, mechanisms for tocopherol isoform regulation of allergic lung inflammation, association of vitamin E isoforms with outcomes in clinical studies, and how the variation in global prevalence of asthma may be explained, at least in part, by vitamin E isoforms.

Isoforms of Vitamin E Differentially Regulate PKC α and Inflammation: A Review

Vitamin E regulation of disease has been extensively studied but most studies focus on the α-tocopherol isoform of vitamin E. These reports indicate contradictory outcomes for anti-inflammatory functions of the α-tocopherol isoform of vitamin E with regards to animal and clinical studies. These seemingly disparate results are consistent with our recent studies demonstrating that purified natural forms of vitamin E have opposing regulatory functions during inflammation. In this review, we discuss that α-tocopherol inhibits whereas γ-tocopherol elevates allergic inflammation, airway hyperresponsiveness, leukocyte transendothelial migration, and endothelial cell adhesion molecule signaling through protein kinase Cα. Moreover, we have demonstrated that α-tocopherol is an antagonist and γ-tocopherol is an agonist of PKCα through direct binding to a regulatory domain of PKCα. In summary, we have determined mechanisms for opposing regulatory functions of α-tocopherol and γ-tocopherol on inflammation. Information from our studies will have significant impact on the design of clinical studies and on vitamin E consumption.

Vitamin D and asthma in children

Vitamin D deficiency and insufficiency are increasingly being recognized in the general population, and have been largely attributed to lifestyle changes (reduced exposure to sunshine due to working indoors or the use of protective clothing and sunscreen; changes in diet) over the last few decades. The musculoskeletal consequences of severe vitamin D deficiency are well established, however, a number of other disorders have now been linked to vitamin D insufficiency, including asthma. There is growing appreciation of the likely importance of vitamin D as a pleiotrophic mediator that contributes to pulmonary health. Children with asthma appear to be at increased risk of vitamin D insufficiency. Epidemiologic data suggest that low serum vitamin D in children with asthma is associated with more symptoms, exacerbations, reduced lung function, increased medication usage and severe disease. In vitro studies have demonstrated that vitamin D enhances steroid responsiveness in adult asthmatics. Vitamin D may play an important role in pulmonary health by inhibiting inflammation, in part through maintaining regulatory T cells, and direct induction of innate antimicrobial mechanisms. More research is required to fully understand the role of vitamin D in the maintenance of airway homeostasis and address the diagnostic and therapeutic implications vitamin D may have in the future of asthma management. This review summarises the current understanding and uncertainties regarding the effect of vitamin D deficiency and insufficiency in children with asthma.

Obesity and pulmonary disease: unanswered questions

Obesity is associated with risk of pulmonary disease, and adversely affects lung function. The parallel increase in obesity and asthma suggests the two conditions are linked; indeed, they can worsen each other. Obesity and inadequate asthma control are associated with poor quality of life, and place a high economic burden on public health. Although the obesity-lung interaction is a major issue for basic research and clinical studies, various questions remain unanswered. Do intrauterine and early life factors impact on the development of obesity and lung disease? If so, can this be prevented? Asthma is generally more severe in obese subjects, but is adiposity a driver of a new asthma phenotype that features greater morbidity and mortality, worse control and decreased response to medications? Obese individuals have small lung volumes, hence their airway calibre is reduced and airway resistance is increased. What puzzles physicians is whether peripheral airways undergo remodelling, which would increase bronchoconstriction. Obese asthmatics respond suboptimally to anti-inflammatory treatment, which raises the question: 'what drug for what patient?' Life expectancy is decreased in obesity and in chronic pulmonary disorders, but does obesity protect against or trigger chronic obstructive pulmonary disease? The time has come to find answers to these questions.

Omega-3 fatty acids and pregnancy: current implications for practice

PURPOSE OF REVIEW

We conducted this review to evaluate the evidence for maternal supplementation with omega-3 fatty acids during pregnancy for the prevention or treatment of common complications of pregnancy including preterm birth, pregnancy-induced hypertension and preeclampsia, as well as perinatal depression. We also evaluated the evidence supporting maternal omega-3 fatty acid supplementation to optimize infant neurocognitive development and for primary prevention of allergic diseases in childhood.

RECENT FINDINGS

Omega-3 fatty acids through diet or dietary supplementation may reduce the risk for early preterm birth. Preliminary findings from small randomized controlled trials suggest that maternal omega-3 fatty acid supplementation during pregnancy may reduce the risk for allergic disease in childhood, but this observation requires confirmation by large appropriately powered randomized controlled trials. More research is needed before routine maternal supplementation for this indication can be recommended.

SUMMARY

Although it is biologically plausible that maternal omega-3 fatty acid supplementation might prevent a number of pregnancy complications and optimize child health and development, indications for supplementation other than prevention of preterm births are currently investigational.

How changes in nutrition have influenced the development of allergic diseases in childhood

The increasing prevalence of allergic diseases in childhood in the last decades could be linked to concomitant dietary changes, especially with the modified and lower consumption of fruit, vegetables and minerals. The consumption of these foods by pregnant women and children in the first years of life seems to be associated with a reduced risk of asthma and related symptoms. Foods that can prevent the development of wheezing through their antioxidant effects contain vitamin C and selenium; blood levels of these elements correlate negatively with the risk of wheezing. Intake of vitamin E during pregnancy also appears to be correlated with a reduced risk of wheezing for the unborn child. Similarly, low intake of zinc and carotenoids by pregnant women is associated with an increased risk of wheezing and asthma in childhood. Fiber also has anti-inflammatory properties and protective effects against allergic diseases such as atopic dermatitis and asthma. The consumption of fat influences the development of the airways. Populations in Western countries have increased their consumption of n-6 PUFAs and, in parallel, reduced n-3 PUFAs. This has led to decreased production of PGE2, which is believed to have a protective effect against inflammation of the airways. Conflicting hypotheses also concern vitamin D; both an excess and a deficiency of vitamin D, in fact, have been associated with an increased risk of asthma. Further studies on the role of these substances are necessary before any conclusions can be drawn on a clinical level.

Association between biomarker-quantified antioxidant status during pregnancy and infancy and allergic disease during early childhood: a systematic review

Recent findings suggest a significant association between the antioxidant status of pregnant women and of their children during the first years of life and the development of allergic disease during childhood. The aim of this review was to identify all studies that estimated the effect of intake of antioxidants in pregnant women and their children on the development of allergic disease during early childhood. A systematic review was conducted of epidemiological studies featuring original peer-reviewed data on the association between dietary antioxidant status and allergic disease during childhood. A systematic search was performed following the Meta-analysis of Observational Studies in Epidemiology Guidelines. A comprehensive search of the literature yielded 225 studies, 18 of which were selected for the extraction of results and were related to antioxidant status and allergic disease. The systematic review included five prospective cohort studies, four cross-sectional studies, and nine case-control studies. Eight studies reported an important association between antioxidant status and asthma onset during childhood. Similarly, wheezing and eczema were studied as an outcome in six and in five studies, respectively. Recent observational studies suggest that a higher intake of antioxidant vitamins, zinc, and selenium during pregnancy and childhood reduces the likelihood of childhood asthma, wheezing, and eczema.

Maternal dietary patterns during pregnancy and risk of wheeze and eczema in Japanese infants aged 16-24 months: the Osaka Maternal and Child Health Study

BACKGROUND

Maternal diet during pregnancy might influence the development of childhood allergic disorders.

AIMS

  This prospective study examined the relationship between maternal dietary patterns during pregnancy and the risk of wheeze and eczema in the offspring aged 16-24 months.

MATERIALS & METHODS

Subjects were 763 mother-child pairs. Data on maternal intake during pregnancy were assessed with a diet history questionnaire. Dietary patterns were derived from factor analysis of 33 predefined food groups. Symptoms of wheeze and eczema were based on criteria of the International Study of Asthma and Allergies in Childhood. Adjustment was made for maternal age, gestation, residential municipality, family income, maternal and paternal education, maternal and paternal history of allergic disorders, changes in maternal diet in pregnancy, season at baseline, maternal smoking during pregnancy, baby's older siblings, sex, birth weight, age at the third survey, household smoking, and breastfeeding duration.

RESULTS

Three dietary patterns were identified: 'healthy', characterized by high intake of green and yellow vegetables, seaweed, mushrooms, white vegetables, pulses, potatoes, fish, sea products, fruit, and shellfish; 'Western', characterized by high intake of vegetable oil, salt-containing seasonings, beef and pork, processed meat, eggs, chicken, and white vegetables; and 'Japanese', characterized by high intake of rice, miso soup, sea products, and fish. There was a tendency for an inverse exposure-response relationship between the maternal Western pattern during pregnancy and the risk of childhood wheeze by crude analysis. After adjustment for the confounding factors under study, the inverse relationship was strengthened: the adjusted OR between extreme quartiles was 0.59 (95% CI: 0.35-0.98, p for trend = 0.02). No such inverse association was observed for childhood eczema. Neither the maternal healthy pattern nor the Japanese pattern during pregnancy was related to childhood wheeze or eczema.

CONCLUSION

The maternal Western pattern during pregnancy may be preventive against wheeze in the offspring.

Vascular cell adhesion molecule-1 expression and signaling during disease: regulation by reactive oxygen species and antioxidants

The endothelium is immunoregulatory in that inhibiting the function of vascular adhesion molecules blocks leukocyte recruitment and thus tissue inflammation. The function of endothelial cells during leukocyte recruitment is regulated by reactive oxygen species (ROS) and antioxidants. In inflammatory sites and lymph nodes, the endothelium is stimulated to express adhesion molecules that mediate leukocyte binding. Upon leukocyte binding, these adhesion molecules activate endothelial cell signal transduction that then alters endothelial cell shape for the opening of passageways through which leukocytes can migrate. If the stimulation of this opening is blocked, inflammation is blocked. In this review, we focus on the endothelial cell adhesion molecule, vascular cell adhesion molecule-1 (VCAM-1). Expression of VCAM-1 is induced on endothelial cells during inflammatory diseases by several mediators, including ROS. Then, VCAM-1 on the endothelium functions as both a scaffold for leukocyte migration and a trigger of endothelial signaling through NADPH oxidase-generated ROS. These ROS induce signals for the opening of intercellular passageways through which leukocytes migrate. In several inflammatory diseases, inflammation is blocked by inhibition of leukocyte binding to VCAM-1 or by inhibition of VCAM-1 signal transduction. VCAM-1 signal transduction and VCAM-1-dependent inflammation are blocked by antioxidants. Thus, VCAM-1 signaling is a target for intervention by pharmacological agents and by antioxidants during inflammatory diseases. This review discusses ROS and antioxidant functions during activation of VCAM-1 expression and VCAM-1 signaling in inflammatory diseases.

A medical nutrition therapy primer for childhood asthma: current and emerging perspectives

Asthma is the most common chronic disease in children. Prevalence has increased in the past 2 decades and has reached a plateau of approximately 9% of children in the United States, affecting about 6.7 million children. The increased prevalence of childhood asthma has paralleled the increased prevalence in childhood obesity. Changes in diet have also been implicated in the increased prevalence of asthma, among other risk factors. The main symptoms of asthma (ie, wheezing, coughing, and chest tightness) require medical evaluation and monitoring. The cornerstone of asthma management is medication therapy, frequently consisting of inhaled bronchodilators and corticosteroids and, when needed, therapy of corticosteroids by mouth. As part of the multidisciplinary management of this chronic disease, nutrition assessment and follow-up in childhood asthma is necessary to identify and address relevant nutrition-related problems. These problems can involve food-medication interactions, obesity, gastroesophageal reflux disease, food allergies, and other issues; therefore, individualized medical nutrition therapy is warranted. Finally, counseling to achieve a healthy balanced diet is recommended for overall health and weight management. A recent but small number of descriptive investigations agree that adherence to a Mediterranean dietary pattern can be associated with a decreased risk of current asthma symptoms in children. Although this evidence is promising, food interventions are required to substantiate an evidence-based foundation for medical nutrition therapy in childhood asthma. At this time, there is no known health risk if a Mediterranean diet is adopted.

Intake of antioxidants during pregnancy and the risk of allergies and asthma in the offspring

BACKGROUND/OBJECTIVES

The potential immune functions related to the damages induced by oxygen-free radicals suggest that antioxidants may have a role in the development of allergies. The objective was to investigate the association between maternal intake of antioxidants during pregnancy and the risk of asthma, rhinitis and eczema in 5-year-old children.

SUBJECTS/METHODS

This study was on the basis of the Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study, a population-based birth cohort study with 5-year follow-up. Complete information on maternal food frequency questionnaire data and ISAAC (International Study of Asthma and Allergies in Childhood)-based allergic outcomes were available for 2441 children. Cox proportional regression and logistic regression were used for the analyses.

RESULTS

Maternal intake of any of the antioxidants was not significantly associated with the risk of asthma, rhinitis or eczema in the offspring, except for dietary intake of magnesium, which was independently associated with protection against eczema (OR 0.78; 95% CI 0.62-0.97).

CONCLUSION

Maternal intake of dietary magnesium during pregnancy may protect against the risk of eczema in the offspring. We did not confirm previous observations concerning other antioxidants. This may be due to the variable amount of antioxidant intake across studies and also indicative of the hypothesis that there may be a critical time window in pregnancy during which antioxidants might modify the risk of allergies in the offspring.

Isoforms of vitamin E differentially regulate inflammation

Vitamin E regulation of disease has been extensively studied in humans, animal models and cell systems. Most of these studies focus on the α-tocopherol isoform of vitamin E. These reports indicate contradictory outcomes for anti-inflammatory functions of the α-tocopherol isoform of vitamin E, especially with regards to clinical studies of asthma and atherosclerosis. These seemingly disparate clinical results are consistent with recently reported unrecognized properties of isoforms of vitamin E. Recently, it has been reported that physiological levels of purified natural forms of vitamin E have opposing regulatory functions during inflammation. These opposing regulatory functions by physiological levels of vitamin E isoforms impact interpretations of previous studies on vitamin E. Moreover, additional recent studies also indicate that the effects of vitamin E isoforms on inflammation are only partially reversible using physiological levels of a vitamin E isoform with opposing immunoregulatory function. Thus, this further influences interpretations of previous studies with vitamin E in which there was inflammation and substantial vitamin E isoforms present before the initiation of the study. In summary, this review will discuss regulation of inflammation by vitamin E, including alternative interpretations of previous studies in the literature with regards to vitamin E isoforms.

Association of maternal anemia with increased wheeze and asthma in children

BACKGROUND

Increasing interest has focused on maternal nutrition and micronutrient status during pregnancy and respiratory disease development in the offspring.

OBJECTIVE

To examine the relationship between maternal anemia in pregnancy with wheeze and asthma in early childhood.

METHODS

The cohort included children of women followed through pregnancy and recontacted when the child was 6 years of age to evaluate respiratory health. Exposure was assessed using maternal anemia diagnosis and hemoglobin (Hgb) < 11 during delivery hospitalization. Study outcomes include wheezing in early childhood; patterns of wheeze from birth to age 6 (early-onset transient wheeze; late-onset wheeze; early-onset persistent wheeze); and diagnosis of childhood asthma.

RESULTS

Maternal anemia was reported by 11.9% of mothers and was associated with recurrent infant wheeze in the first year (adjusted odds ratio [ORa] = 2.17, 95% confidence interval [CI] 1.18, 4.00), wheezing before age 3 (Ora = 2.42, 95% CI 1.38, 4.23), and early-onset transient and early-onset persistent wheeze patterns (Ora = 2.81, 95%CI 1.38, 5.72, and Ora = 2.07, 95% CI 1.02, 4.22), respectively. Among children of mothers with asthma, maternal anemia was associated with recurrent wheeze in year 1 (Ora = 4.22, 95% CI 1.65, 10.80) and wheeze before age 3 (Ora = 2.73, 95% CI 1.17, 6.35). Offspring of mothers with asthma also had increased odds of asthma diagnosis (Ora = 2.53, 95% CI 1.04, 6.17) and current asthma (Ora = 3.46, 95% CI 1.45, 8.26).

CONCLUSIONS

Maternal anemia during pregnancy is associated with infant respiratory health outcomes. If this observation is replicated, maternal anemia may be a target for intervention and future research.

Using genetics to predict the natural history of asthma?

Clinical practice reminds us that there is considerable variability in the course of asthma over time. Treatment of patients with asthma would be considerably improved if one could accurately predict the likely course of disease over the life course. Recently, with the advent of the era of genome-wide association studies, there has been a monumental shift in our understanding of the genetic factors that underlie inherited susceptibility to asthma. Genes have been identified that modulate many aspects of the natural history of asthma, such as susceptibility to atopy, altered lung development, and susceptibility to more severe disease. Heritability studies have even suggested a role for genetic factors in remission of asthma. However, although the discovery of novel genetic factors underlying disease susceptibility has undoubtedly improved our understanding of disease pathogenesis, whether these advances have improved the ability to predict the natural history in individual patients is questionable, and the application of genetic testing to clinical practice remains some way off.

Tolerizing allergic responses in the lung

The absolute requirement of the pulmonary immune system is to limit the inflammatory consequences of inhaled infectious agents while maintaining tolerance to harmless aeroallergens. This tolerance is maintained by a complex network of cells and molecules interacting with lung stromal cells. However, in some individuals there is a breakdown in tolerance to particles such as pollens, animal dander, or dust, resulting in the development of allergic pathology. Emerging evidence suggests that this breakdown in tolerance is influenced by the genetic background of individuals as well as environmental considerations such as early exposure to respiratory pathogens. Further understanding of the mechanisms used by the pulmonary immune system to maintain tolerance might result in exploitation of novel avenues for therapy to treat the growing number of chronic asthmatic patients.

Immunology of pregnancy

The conceptual framework for reproductive immunology was put in place over 50 years ago when the survival of the fetal semi-allograft within an immunocompetent mother was first considered. During this time, a number of paradigms have emerged and the mechanisms receiving current attention are those related to immune tolerance, such as regulatory T-cells and indoleamine 2,3,-dioxygenase, and innate immunity, such as natural killer cells, trophoblast debris and inflammation. A key consideration is the temporal and spatial variation in any of these pathways (e.g. implantation v. parturition). As fetally derived trophoblasts are the semi-allogeneic cells with which the maternal immune system comes into contact, understanding the immune response to these cells is critical. There is much interest in the immunological pathways that support a healthy pregnancy and how they might be perturbed in adverse pregnancy outcomes. Additionally, there is increasing awareness that antenatal determinants of the immune function of pregnant women and their offspring have consequences for health and disease in childhood and beyond. Changes in maternal diet over recent decades coincide with the increasing prevalence of allergic and other immune-mediated diseases, and the modification of maternal diet has emerged as a strategy for disease prevention. Approaches undergoing trial at numerous sites around the world include dietary supplementation with fish oil and/or probiotics. Understanding the underlying mechanisms of any positive effect on disease outcomes should reveal further novel strategies for disease prevention.

Maternal diet during pregnancy: an emerging risk factor for childhood asthma

Evaluation of: Willers SM, Wijga AH, Brunekreef B et al. Maternal food consumption during pregnancy and the longitudinal development of childhood asthma. Am. J. Respir. Crit. Care Med. 178, 124-131 (2008). It has been hypothesized that the recent marked increase in the prevalence of asthma may, in part, be a consequence of changing diet. There is increasing interest in the possibility that childhood asthma may be influenced by maternal diet during pregnancy and an increasing number of studies have highlighted associations between childhood asthma and maternal intake of certain foods (e.g., fish, fruits and vegetables) and nutrients (e.g., vitamin E, vitamin D, zinc and polyunsaturated fatty acids) during pregnancy. Maternal diet during pregnancy has the potential to influence fetal immune and airway development during a critical period of life with long-term irreversible consequences, such as childhood asthma. Further research, particularly intervention studies, needs to be carried out to establish whether dietary intervention during pregnancy can be used as a healthy, low-cost, public-health measure to reduce the prevalence of childhood asthma.

Consumption of vegetables, fruit, and antioxidants during pregnancy and wheeze and eczema in infants

BACKGROUND

Two previous cohort studies showed inverse relationships between maternal vitamin E and zinc intake during pregnancy and the risk of wheeze and/or asthma in the offspring. We investigated the association between maternal intake of vegetables, fruit, and selected antioxidants during pregnancy and the risk of wheeze and eczema in the offspring aged 16-24 months.

METHODS

Subjects were 763 Japanese mother-child pairs. Data on maternal intake during pregnancy were assessed with a diet history questionnaire. Data on symptoms of wheeze and eczema were based on criteria of the International Study of Asthma and Allergies in Childhood.

RESULTS

Higher maternal intake of green and yellow vegetables, citrus fruit, and beta-carotene during pregnancy was significantly associated with a reduced risk of eczema, but not wheeze, in the offspring {adjusted odds ratios (ORs) between extreme quartiles [95% confidence intervals (CIs)] = 0.41 (0.24-0.71), 0.53 (0.30-0.93), and 0.52 (0.30-0.89), respectively}. Maternal vitamin E consumption during pregnancy was significantly inversely related to the risk of infantile wheeze, but not eczema [adjusted OR (95% CI) = 0.54 (0.32-0.90)]. No statistically significant exposure-response associations were observed between maternal intake of total vegetables, vegetables other than green and yellow vegetables, total fruit, apples, alpha-carotene, vitamin C, or zinc and the risk of wheeze or eczema in the children.

CONCLUSIONS

Higher maternal consumption of green and yellow vegetables, citrus fruit, and beta-carotene during pregnancy may be protective against the development of eczema in the offspring. Higher maternal vitamin E intake during pregnancy may reduce the risk of infantile wheeze.

Effect of feeding a formula supplemented with long-chain polyunsaturated fatty acids for 14 weeks improves the ex vivo response to a mitogen and reduces the response to a soy protein in infants at low risk for allergy

BACKGROUND AND OBJECTIVE

Feeding long-chain polyunsaturated fatty acids (LCP) influences immunity in adults; however, less is known about their effect during development. The aim of the study was to determine the effect of feeding LCP on immunity in healthy infants during the first 4 months of life.

PATIENTS AND METHODS

Formula-fed infants were randomized at <or=14 days of age to standard term formula (Formula) or formula containing LCP (Formula+LCP). Infants exclusively fed human milk (HM) were included for comparison. At 16 weeks of age, blood was collected and phenotypes, the ability to proliferate and produce cytokines (interleukin [IL]-2, IL-4, IL-6, IL-10, IL-12, interferon [IFN]-gamma, tumor necrosis factor [TNF]-alpha, TGF-beta) after incubation with phytohemaglutinin (PHA), beta-lactoglobulin, or soy protein were measured.

RESULTS

Feeding LCP resulted in a higher than and more similar proliferation rate to PHA in HM-fed infants, possibly because of a greater TH1 type cytokine response and a higher percentage of antigen mature (CD45RO+) cells (P < 0.05). The response to beta-lactoglobulin did not differ among groups. After incubation with soy protein Formula+LCP, compared with Formula produced less IL-2 and more TNF-alpha and had a higher percentage of CD8+ and a lower percentage of CD20+ (CD20+CD54+) cells poststimulation (P < 0.05). Both formula groups produced less IL-2 after PHA, had a lower percentage of CD80+ cells, and a higher percentage of CD54+ cells after incubation with food proteins (P < 0.05).

CONCLUSIONS

Formula-fed infants, at low risk for allergy, respond differently to mitogen and food proteins ex vivo than those fed HM. Feeding LCP altered some of these differences in the direction that is hypothesized to confer immune benefits.

Olive oil during pregnancy is associated with reduced wheezing during the first year of life of the offspring

OBJECTIVE

To test the hypothesis that consuming Mediterranean diet and using olive oil for cooking/dressing salads during pregnancy might be associated with less wheezing during the first year of the offspring's life.

METHODS

A study was conducted in 1,409 infants (mean age, 16.6 +/- 2.5 months) attending healthy infant clinics in Spain. Dietary data of mothers' intake during pregnancy was collected by means of a parental food frequency questionnaire. Demographic information and data on wheezing during the first year of the offspring's life were also recorded. Infants were stratified according to any wheezing (42.2%) during the first year of life.

RESULTS

In the univariate analysis, adherence to a Mediterranean diet and using olive oil for cooking/dressing salads during pregnancy were both significantly associated with less wheezing during the first year of life. However, after multivariate analysis, only olive oil consumption during pregnancy remained associated with less wheezing in the studied period (aOR = 0.57 [95% CI = 0.4-0.9]); whereas male gender (1.8 [1.4-2.3]), day care attendance (2.15 [1.5-3.1]), maternal asthma (2.16 [1.3-3.6]), maternal smoking during pregnancy (1.83 [1.3-2.2]), infant eczema (1.95 [1.3-2.9]), and mould stains on the household walls (1.72 [1.2-2.5]) remained associated with wheezing.

CONCLUSION

Our findings suggest a protective effect (primary prevention) of olive oil use during pregnancy on wheezing during the first year of the offspring's life.

Maternal diet during pregnancy and allergic sensitization in the offspring by 5 yrs of age: a prospective cohort study

To examine the effect of maternal diet during pregnancy on allergic sensitization in the offspring by 5 yrs of age. The Finnish type 1 Diabetes Prediction and Prevention Nutrition Study. A population-based cohort study with 5-yr follow-up. A total of 931 children with human leukocyte antigen-conferred susceptibility to type 1 diabetes for whom maternal pregnancy food frequency questionnaire data and allergen-specific immunoglobulin E measurement at 5 yrs were available. Increasing maternal consumption of citrus fruits [odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.05-1.25] and total fruit (OR = 1.36, 95% CI = 1.09-1.70) were positively associated with sensitization to inhalant allergens, after adjustment for potential confounders. Maternal intake of vitamin D (OR = 0.56, 95% CI = 0.35-0.91) was inversely associated with sensitization to food allergens. Maternal consumption of citrus fruits during pregnancy may increase the risk to allergic sensitization in the offspring, whereas vitamin D intake may have a beneficial effect. Further studies are required to define more closely the putative effect of maternal intake of polyunsaturated fatty acids on development of allergic diseases in the offspring.

Antioxidant nutrient intakes and corresponding biomarkers associated with the risk of atopic dermatitis in young children

BACKGROUND/OBJECTIVES

To investigate the association of antioxidant nutritional status with the risk of atopic dermatitis (AD) in young children in a case-control, population-based study.

SUBJECTS/METHODS

Identified from preschools by using the Korean version of the International Study of Asthma and Allergies in Childhood (ISAAC). Final analysis included 180 AD (mean age 5.3+/-0.9 years) and 242 non-AD (mean age 5.2+/-1.0 years) children. Diet was assessed using a validated semi-quantitative food frequency questionnaire. Fasting blood samples were used for analyses of fat-soluble vitamins (retinol, alpha-tocopherol, and beta-carotene) and vitamin C.

RESULTS

AD was associated negatively with intakes of antioxidant-related nutrients. The adjusted odds ratio (OR) and 95% confidence interval (95% CI) were 0.44 (0.22-0.88) for the highest (vs lowest) quintile of beta-carotene. A similar association was observed for dietary vitamin E (OR=0.33, 95% CI=0.16-0.67), folic acid (OR=0.37, 95% CI=0.18-0.73), and iron (OR=0.39, 95% CI=0.19-0.79). Reduced AD risk was found with 1 s.d. increase of serum alpha-tocopherol [OR=0.64, 95% CI=0.41-0.98) and retinol (OR=0.74, 95% CI=0.58-0.96) concentrations, and marginally with that of serum beta-carotene levels (P=0.0749 for trend). There was no relationship of AD risk with dietary and plasma vitamin C as well as nutrient supplement intake regardless of nutrient type. AD was predicted better by the intake measure than the corresponding blood biomarker regarding vitamin E and beta-carotene.

CONCLUSIONS

These findings suggest that higher antioxidant nutritional status reduces the risk of AD and that such risk-reduction effects depend on nutrient type.

Use of multivitamin supplements in relation to allergic disease in 8-y-old children

BACKGROUND

Multivitamins are frequently consumed by children, but it is unclear whether this affects the risk of allergic disease.

OBJECTIVE

We sought to study the association between multivitamin supplementation and allergic disease in 8-y-old children.

DESIGN

Data were obtained from a Swedish birth cohort study. Information on lifestyle factors, including use of vitamin supplements, environmental exposures, and symptoms and diagnoses of allergic diseases, was obtained by parental questionnaires. In addition, allergen-specific IgE concentrations of food and airborne allergens were measured in blood samples collected at age 8 y. A total of 2423 children were included in the study. The association between use of vitamin supplements and the selected health outcomes was analyzed with logistic regression.

RESULTS

Overall, no strong and consistent associations were observed between current multivitamin use and asthma, allergic rhinitis, eczema, or atopic sensitization at age 8 y. However, children who reported that they started taking multivitamins before or at age 4 y had a decreased risk of sensitization to food allergens (odds ratio: 0.61; 95% CI: 0.39, 0.97) and tendencies toward inverse associations with allergic rhinitis. In contrast, there was no consistent association among children who started to use multivitamins at or after age 5 y.

CONCLUSION

Our results show no association between current use of multivitamins and risk of allergic disease but suggest that supplementation with multivitamins during the first years of life may reduce the risk of allergic disease at school age.

Prenatal and childhood Mediterranean diet and the development of asthma and allergies in children

Objective

To discuss current evidence about the relation between prenatal and childhood Mediterranean diet, and the development of asthma and allergies in children.

Design

Review of the literature.

Setting and results

Four recent studies conducted in Mediterranean countries (Spain, Greece) and one conducted in Mexico evaluated the association between childhood Mediterranean diet and asthma outcomes in children. All of the studies reported beneficial associations between a high level of adherence to the Mediterranean diet during childhood and symptoms of asthma or allergic rhinitis. Individual foods or food groups contributing to the protective effect of Mediterranean diet included fish, fruits, vegetables, legumes, nuts and cereals, while detrimental components included red meat, margarine and junk food intake.

Two studies focused on prenatal Mediterranean diet: the first is a birth cohort in Spain that showed a protective effect of a high adherence to the Mediterranean diet during pregnancy on persistent wheeze, atopic wheeze and atopy at the age of 6·5 years; while the second is a cross-sectional study in Mexico, collecting information more than 6 years after pregnancy, that showed no associations between maternal Mediterranean diet during pregnancy and allergic symptoms in childhood except for current sneezing.

Conclusions

Findings from recent studies suggest that a high level of adherence to the Mediterranean diet early in life protects against the development of asthma and atopy in children. Further studies are needed to better understand the mechanisms of this protective effect, to evaluate the most relevant window of exposure, and to address specific components of diet in relation to disease.

Diet and asthma: looking back, moving forward

Asthma is an increasing global health burden, especially in the western world. Public health interventions are sought to lessen its prevalence or severity, and diet and nutrition have been identified as potential factors. With rapid changes in diet being one of the hallmarks of westernization, nutrition may play a key role in affecting the complex genetics and developmental pathophysiology of asthma. The present review investigates hypotheses about hygiene, antioxidants, lipids and other nutrients, food types and dietary patterns, breastfeeding, probiotics and intestinal microbiota, vitamin D, maternal diet, and genetics. Early hypotheses analyzed population level trends and focused on major dietary factors such as antioxidants and lipids. More recently, larger dietary patterns beyond individual nutrients have been investigated such as obesity, fast foods, and the Mediterranean diet. Despite some promising hypotheses and findings, there has been no conclusive evidence about the role of specific nutrients, food types, or dietary patterns past early childhood on asthma prevalence. However, diet has been linked to the development of the fetus and child. Breastfeeding provides immunological protection when the infant's immune system is immature and a modest protective effect against wheeze in early childhood. Moreover, maternal diet may be a significant factor in the development of the fetal airway and immune system. As asthma is a complex disease of gene-environment interactions, maternal diet may play an epigenetic role in sensitizing fetal airways to respond abnormally to environmental insults. Recent hypotheses show promise in a biological approach in which the effects of dietary factors on individual physiology and immunology are analyzed before expansion into larger population studies. Thus, collaboration is required by various groups in studying this enigma from epidemiologists to geneticists to immunologists. It is now apparent that this multidisciplinary approach is required to move forward and understand the complexity of the interaction of dietary factors and asthma.

Omega-3 fatty acids, vitamin C and Zn supplementation in asthmatic children: a randomized self-controlled study

OBJECTIVES

Bronchial asthma is a chronic inflammatory airways disease. Nutritional intervention is an important tool to decrease the severity of many chronic inflammatory diseases including asthma. The aim of this study is to evaluate the role of omega-3 fatty acids, vitamin C and Zn in children with moderately persistent asthma.

PATIENTS AND METHODS

Randomly assigned, placebo-self-controlled 60 children with moderate persistent asthma completed the study, were subjected to alternating phases of supplementation with omega-3 fatty acids, vitamin C and Zn either singly or in combination separated with washout phases. Childhood asthma control test (C-ACT), pulmonary function tests and sputum inflammatory markers were evaluated at the beginning of the study and at the end of each therapeutic phase.

RESULTS

There was a significant improvement of C-ACT, pulmonary function tests and sputum inflammatory markers with diet supplementation with omega-3 fatty acids, vitamin C and Zn (p < 0.001*). There was also significant improvement with the combined use of the three supplementations than single use of any one of them (p < 0.001*).

CONCLUSION

Diet supplementation with omega-3 fatty acids, Zn and vitamin C significantly improved asthma control test, pulmonary function tests and pulmonary inflammatory markers in children with moderately persistent bronchial asthma either singly or in combination.

Early-life environment, developmental immunotoxicology, and the risk of pediatric allergic disease including asthma

Incidence of childhood allergic disease including asthma (AD-A) has risen since the mid-20th century with much of the increase linked to changes in environment affecting the immune system. Childhood allergy is an early life disease where predisposing environmental exposures, sensitization, and onset of symptoms all occur before adulthood. Predisposition toward allergic disease (AD) is among the constellation of adverse outcomes following developmental immunotoxicity (DIT; problematic exposure of the developing immune system to xenobiotics and physical environmental factors). Because novel immune maturation events occur in early life, and the pregnancy state itself imposes certain restrictions on immune functional development, the period from mid-gestation until 2 years after birth is one of particular concern relative to DIT and AD-A. Several prenatal-perinatal risk factors have been identified as contributing to a DIT-mediated immune dysfunction and increased risk of AD. These include maternal smoking, environmental tobacco smoke, diesel exhaust and traffic-related particles, heavy metals, antibiotics, environmental estrogens and other endocrine disruptors, and alcohol. Diet and microbial exposure also significantly influence immune maturation and risk of allergy. This review considers (1) the critical developmental windows of vulnerability for the immune system that appear to be targets for risk of AD, (2) a model in which the immune system of the DIT-affected infant exhibits immune dysfunction skewed toward AD, and (3) the lack of allergy-relevant safety testing of drugs and chemicals that could identify DIT hazards and minimize problematic exposure of pregnant women and children.

Vitamin D and human health: lessons from vitamin D receptor null mice

The vitamin D endocrine system is essential for calcium and bone homeostasis. The precise mode of action and the full spectrum of activities of the vitamin D hormone, 1,25-dihydroxyvitamin D [1,25-(OH)(2)D], can now be better evaluated by critical analysis of mice with engineered deletion of the vitamin D receptor (VDR). Absence of a functional VDR or the key activating enzyme, 25-OHD-1alpha-hydroxylase (CYP27B1), in mice creates a bone and growth plate phenotype that mimics humans with the same congenital disease or severe vitamin D deficiency. The intestine is the key target for the VDR because high calcium intake, or selective VDR rescue in the intestine, restores a normal bone and growth plate phenotype. The VDR is nearly ubiquitously expressed, and almost all cells respond to 1,25-(OH)(2)D exposure; about 3% of the mouse or human genome is regulated, directly and/or indirectly, by the vitamin D endocrine system, suggesting a more widespread function. VDR-deficient mice, but not vitamin D- or 1alpha-hydroxylase-deficient mice, and man develop total alopecia, indicating that the function of the VDR and its ligand is not fully overlapping. The immune system of VDR- or vitamin D-deficient mice is grossly normal but shows increased sensitivity to autoimmune diseases such as inflammatory bowel disease or type 1 diabetes after exposure to predisposing factors. VDR-deficient mice do not have a spontaneous increase in cancer but are more prone to oncogene- or chemocarcinogen-induced tumors. They also develop high renin hypertension, cardiac hypertrophy, and increased thrombogenicity. Vitamin D deficiency in humans is associated with increased prevalence of diseases, as predicted by the VDR null phenotype. Prospective vitamin D supplementation studies with multiple noncalcemic endpoints are needed to define the benefits of an optimal vitamin D status.