Fatty acid intake and asthma symptoms in Japanese children: the Ryukyus Child Health Study

Association of allergies in children younger than 3 years with levels of maternal intake of n-3 polyunsaturated fatty acids or fish during pregnancy: A nationwide birth cohort study, the Japan Environment and Children's Study

BACKGROUND

N-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory properties and are expected to prevent the onset of allergies. However, epidemiological studies investigating the relationship between child allergies and maternal intake of n-3 PUFAs or fish have yielded inconsistent results.

METHODS

Following exclusions from a dataset comprising 103,057 records from the Japan Environment and Children's Study, 72,105 participants were divided into five groups according to mothers' intake of n-3 PUFAs or fish during pregnancy to assess the risk of their children being diagnosed with allergy by 3 years old. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for child allergies were calculated using multivariable logistic regression analyses with reference to the lowest intake group.

RESULTS

Levels of maternal intake of n-3 PUFAs or fish showed inverted associations (i.e., reduced risk) with the incidence of physician-diagnosed allergic rhinoconjunctivitis or parent-reported symptoms of current rhinitis with eye symptoms at different time points and the cumulative incidence from birth to 3 years of age. Inverted associations were also found for current wheeze at 1-<2 years of age and current eczema at 1-<2 and 0-<3 years of age. However, for food allergies, no significant associations were observed in the incidence in each group compared with the lowest intake group at any age.

CONCLUSIONS

The findings suggest that n-3 PUFA intake during pregnancy may reduce the risk of developing allergic diseases and symptoms in children. In addition, consumption of n-3 PUFAs or fish is very unlikely to increase the risk of allergy given that the results are from a country with high fish consumption.

TRIAL REGISTRATION

UMIN000030786 https://rctportal.niph.go.jp/detail/um?trial_id=UMIN000030786.

The re-emerging role of linoleic acid in paediatric asthma

Asthma is the most common chronic disease within the paediatric population. Although it is multifactorial, its onset may be linked to early-life exposures with subsequent impact on immune system development. Microbial and dietary metabolic products have been implicated in the development and exacerbation of paediatric asthma. Linoleic acid is the most common omega-6 polyunsaturated fatty acid in the Western diet. In this review, we summarise the literature regarding the involvement of linoleic acid in the development of and its impact on existing paediatric asthma. First, we summarise the existing knowledge surrounding the relationship between human microbial metabolism and allergic diseases in children. Next, we examine cellular or animal model-based mechanistic studies that investigated the impact of dietary- and microbial-derived linoleic acid metabolites on asthma. Finally, we review the literature investigating the impact of linoleic acid metabolites on the development and exacerbation of childhood asthma. While there is conflicting evidence, there is growing support for a role of linoleic acid in the onset and pathophysiology of asthma. We recommend that additional cellular, animal, and longitudinal studies are performed that target linoleic acid and its metabolites.

The association between n-3 polyunsaturated fatty acid intakes and asthma in US children and adolescents: A cross-sectional study from NHANES

BACKGROUND

Asthma is an inflammatory disease. The potential of n-3 polyunsaturated fatty acids (PUFAs) to alleviate asthma symptoms through their anti-inflammatory effects and immune modulation has been explored. However, the precise role of dietary n-3 PUFAs in childhood and adolescent asthma remains unclear.

OBJECTIVE

This study aimed to evaluate the association between dietary n-3 PUFAs intake and asthma in children and adolescents in the United States.

METHODS

We conducted a cross-sectional analysis of 8543 children and adolescents from the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2020 by adjusting for covariates and using multivariate logistic regression, restricted cubic spline, threshold effects, and subgroup analyses.

RESULTS

Among 8354 participants, 1456 (16.5%) self-reported diagnosis of asthma by a healthcare provider. After adjusting for potential confounding factors, compared with individuals in the lowest n-3 PUFA consumption group (T1, <26.07 mg/kg/day), the adjusted odds ratio (OR) for asthma was 0.71 (95% CI: 0.6-0.84, p < .001) in the second group (T2, 26.07-48.93 mg/kg/day) and 0.58 (95% CI: 0.47-0.73, p < .001) in the third group (T3, >48.93 mg/kg/day). Furthermore, a nonlinear (L-shaped) relationship was observed between n-3 PUFA intake and asthma (p = .009), with subgroup and sensitivity analyses confirming the stability of the results. In the threshold analysis, a critical turning point was observed at approximately 59.0 mg/kg/day (OR = 0.984, 95% CI: 0.977-0.991, p < .001).

CONCLUSION

Dietary intake of n-3 PUFAs exhibited an L-shaped relationship with asthma in children and adolescents in the United States, with a critical turning point observed at approximately 59.0 mg/kg/day.

The association of polyunsaturated fatty acids and asthma: a cross-sectional study

BACKGROUND

To examine the relationships between polyunsaturated fatty acids (PUFAs) dietary intake and asthma in children.

METHODS

In this cross-sectional study, a total of 14,727 participants from the United States National Health and Nutrition Examination Survey (NHANES) database in 1999-2018 were included, and the baseline characteristics of all participants were gathered. The description analysis was used to explore the possible covariates. Weighted multivariate logistic regression models were adopted to assessed the association between PUFAs dietary intake and asthma in children. In addition, we also performed subgroup analysis based on gender, age, and maternal smoking during pregnancy to investigate this relationship.

RESULTS

The prevalence of asthma approximately was 15.38% in the present study. The result of weighted multivariate logistic regression indicated that, docosahexaenoic [weighted odds ratio (OR) = 0.37, 95% confidence interval (CI) 0.19-0.74], total n - 3 PUFAs (weighted OR = 0.63, 95%CI 0.43-0.91), and eicosapentaenoic (weighted OR = 0.35, 95%CI 0.13-0.95) dietary intake were negatively associated with asthma in children. The subgroup analysis described that when children were male (weighted OR = 0.28, 95%CI 0.10-0.84), or were 5-7 years (weighted OR = 0.04, 95%CI 0.01-0.37), were 7-12 years (weighted OR = 0.46, 95%CI 0.24-0.90), or their maternal smoking during pregnancy (weighted OR = 0.16, 95%CI 0.03-0.90), docosahexaenoic dietary intake was negatively related to childhood asthma.

CONCLUSION

Docosahexaenoic dietary intake was negatively associated with the asthma in children, especially if children were male, or were 5-12 years, or their maternal smoking during pregnancy.

Dietary intake and plasma concentrations of PUFAs in childhood and adolescence in relation to asthma and lung function up to adulthood

BACKGROUND

PUFAs may influence the risk of asthma; however, long-term prospective studies including objective biomarkers of PUFA intake are lacking.

OBJECTIVES

The objective was to investigate the role of dietary intake and plasma concentrations of n-3 and n-6 (ω-3 and ω-6) PUFAs in childhood and adolescence for the development of asthma and lung function up to young adulthood.

METHODS

The study included participants from the Swedish prospective birth cohort BAMSE. Dietary intake of PUFAs was calculated from FFQs (n = 1992) and plasma proportions of PUFAs were measured in phospholipids (n = 831). We analyzed the n-3 PUFA α-linolenic acid (ALA; 18:3n-3); the sum of very-long-chain (VLC) n-3 PUFAs: EPA (20:5n-3), DHA (22:6n-3), and docosapentaenoic acid (22:5n-3); and the n-6 PUFAs linoleic acid (LA; 18:2n-6) and arachidonic acid (AA; 20:4n-6). Asthma was assessed by questionnaires at 8, 16, and 24 y and lung function was measured by spirometry at 24 y.

RESULTS

A high (≥median) self-reported dietary intake of LA at 8 y and AA at 16 y was associated with increased risk of prevalent asthma at 24 y (OR: 1.41; 95% CI: 1.10, 1.82 and OR: 1.32; 95% CI: 1.02, 1.70, respectively). In contrast, plasma proportions of ALA, ∑VLC n-3 PUFAs, and AA at 8 y, as well as LA at 16 y, were inversely associated with prevalent asthma at 24 y (e.g., OR: 0.55; 95% CI: 0.38, 0.81 for ∑VLC n-3 PUFAs). No consistent associations were observed with lung function.

CONCLUSIONS

High dietary intake of certain n-6 PUFAs in childhood or adolescence may be associated with increased risk of asthma up to young adulthood, whereas dietary biomarkers of certain n-3 and n-6 PUFAs in plasma may be associated with decreased risk. Thus, the role of diet compared with altered metabolism of PUFAs needs further investigation to improve dietary preventive strategies for asthma.

The Influence of Dietary Fatty Acids on Immune Responses

Diet-derived fatty acids (FAs) are essential sources of energy and fundamental structural components of cells. They also play important roles in the modulation of immune responses in health and disease. Saturated and unsaturated FAs influence the effector and regulatory functions of innate and adaptive immune cells by changing membrane composition and fluidity and by acting through specific receptors. Impaired balance of saturated/unsaturated FAs, as well as n-6/n-3 polyunsaturated FAs has significant consequences on immune system homeostasis, contributing to the development of many allergic, autoimmune, and metabolic diseases. In this paper, we discuss up-to-date knowledge and the clinical relevance of the influence of dietary FAs on the biology, homeostasis, and functions of epithelial cells, macrophages, dendritic cells, neutrophils, innate lymphoid cells, T cells and B cells. Additionally, we review the effects of dietary FAs on the pathogenesis of many diseases, including asthma, allergic rhinitis, food allergy, atopic dermatitis, rheumatoid arthritis, multiple sclerosis as well as type 1 and 2 diabetes.

The role of linoleic acid in asthma and inflammatory markers: a Mendelian randomization study

BACKGROUND

Asthma is a common respiratory disease, possibly caused by autoimmunity. Linoleic acid (LA), the main n-6 (ω-6) PUFA from widely used vegetable oils, is thought to suppress immune responses that might have benefits for asthma. However, this question has not been examined in randomized controlled trials.

OBJECTIVES

To obtain unconfounded estimates, we assessed how genetically predicted LA affected asthma using 2-sample Mendelian randomization. We also examined its role in white blood cell traits (eosinophil, neutrophil, and low monocyte counts) identified as potential causal factors in asthma.

METHODS

We used 18 uncorrelated, genome-wide significant genetic variants to predict LA, which we applied to a large genetic case (n = 19,954)-control (n = 107,715) study of asthma, to the UK Biobank (408,961 people of European ancestry with 26,332 asthma cases), and for white blood cell traits to the UK Biobank. We also repeated the analysis on asthma using 29 replicated, functionally relevant genetic variants. In addition, we examined the role of asthma in LA to assess reverse causality.

RESULTS

Genetically predicted LA was associated with lower risk of asthma (OR: 0.89 per SD increase in LA; 95% CI: 0.85, 0.93), with no association of asthma with LA. Genetically predicted LA was associated with lower eosinophil count (-0.03; 95% CI: -0.061, -0.004) and lower neutrophil count (-0.04; 95% CI: -0.057, -0.023). These estimates were robust to different selections of genetic variants and sensitivity analyses.

CONCLUSIONS

LA might protect against asthma possibly via white blood cell traits, with relevance to the identification of effective new interventions for asthma.

EAACI position paper: Influence of dietary fatty acids on asthma, food allergy, and atopic dermatitis

The prevalence of allergic diseases such as allergic rhinitis, asthma, food allergy, and atopic dermatitis has increased dramatically during the last decades, which is associated with altered environmental exposures and lifestyle practices. The purpose of this review was to highlight the potential role for dietary fatty acids, in the prevention and management of these disorders. In addition to their nutritive value, fatty acids have important immunoregulatory effects. Fatty acid-associated biological mechanisms, human epidemiology, and intervention studies are summarized in this review. The influence of genetics and the microbiome on fatty acid metabolism is also discussed. Despite critical gaps in our current knowledge, it is increasingly apparent that dietary intake of fatty acids may influence the development of inflammatory and tolerogenic immune responses. However, the lack of standardized formats (ie, food versus supplement) and standardized doses, and frequently a lack of prestudy serum fatty acid level assessments in clinical studies significantly limit our ability to compare allergy outcomes across studies and to provide clear recommendations at this time. Future studies must address these limitations and individualized medical approaches should consider the inclusion of specific dietary factors for the prevention and management of asthma, food allergy, and atopic dermatitis.

Diet and asthma in Lebanese schoolchildren: A cross-sectional study

OBJECTIVES

The causes of the global increase in asthma in children are unknown. It has been hypothesized that diet is an important factor that may play a role in the pathogenesis of the disease. The objective was to evaluate the association between diet and current asthma among Lebanese children.

METHODS

A cross-sectional study was conducted on 1000 children recruited from public and private schools in Lebanon. Of the total enrolled participants, 107 children were diagnosed with current asthma and were analyzed. The food frequency questionnaire was used to assess participants' dietary habits.

RESULTS

The consumption of sweets ≥3 times weekly (ORa = 5.42), white bread ≥3 times weekly (ORa = 26.38), and olive oil daily (ORa = 9.80) were associated with higher odds of current asthma. Drinking carbonated beverages occasionally (ORa = 0.25) and ≥3 times per week (ORa = 0.03) was significantly associated with lower odds of current asthma. Adhering to Mediterranean diet (occasional, >3 times weekly and daily) was significantly associated with lower odds of current asthma compared to never consuming Mediterranean diet (ORa = 0.23 and ORa = 0.22, respectively). The occasional consumption of bread was significantly associated with higher odds of current asthma (ORa = 8.2), whereas daily consumption was significantly associated with lower odds (ORa = 0.336). Moreover, the occasional, ≥3 times weekly and daily consumption of meat were significantly associated with higher odds of current asthma (ORa = 9.6; ORa = 5.1 and ORa = 4.5), respectively. An occasional consumption of junk food was significantly associated with lower odds of current asthma (ORa = 0.044), whereas a daily consumption was associated with higher odds.

CONCLUSION

Adhering to certain diets might be associated with higher odds of current asthma.

Dietary intake of fish and ω-3 polyunsaturated fatty acids and physician-diagnosed allergy in Japanese population: The Japan Environment and Children's Study

OBJECTIVE

Emerging evidence from epidemiologic studies and clinical trials indicates that ω-3 polyunsaturated fatty acids (PUFAs) may have a preventive or therapeutic effect on allergy, although the results remain controversial. The aim of this study was to investigate the association between intake of fish and ω-3 PUFAs with risk for lifetime prevalence of physician-diagnosed allergy in a Japanese population.

METHODS

Study participants were 78 621 pregnant women and 42 831 male partners from The Japan Environment and Children's Study. History of physician-diagnosed allergy (asthma, allergic rhinitis/pollinosis, allergic conjunctivitis, or atopic dermatitis) was determined by self-administered questionnaire survey. Dietary intake of fish and ω-3 PUFAs was estimated using a food frequency questionnaire.

RESULTS

Contrary to our hypothesis, an increased risk for allergy was found by multivariable logistic regression in females, especially in allergic rhinitis/pollinosis, allergic conjunctivitis, or atopic dermatitis for fish intake and in allergic rhinitis/pollinosis or allergic conjunctivitis for ω-3 PUFAs. As for male partners, risk for allergic rhinitis/pollinosis or atopic dermatitis was increased for both fish and ω-3 PUFA intake. No statistically significant results were observed for the risk for asthma in either women or men.

CONCLUSION

Fish and ω-3 PUFA intake were associated with increased risk for some allergic diseases. Further research is warranted to confirm these findings in individuals with high fish consumption.

Dietary and Plasma Polyunsaturated Fatty Acids Are Inversely Associated with Asthma and Atopy in Early Childhood

BACKGROUND

Polyunsaturated fatty acids (PUFAs) influence immune function and risk of allergic disease. Prior evidence of the effect of PUFA intake on childhood asthma and allergy is inconclusive.

OBJECTIVES

To investigate associations of PUFA plasma levels and dietary intake with asthma and allergy at age 3 years in this ancillary study of the Vitamin D Antenatal Asthma Reduction Trial.

METHODS

Plasma PUFA levels were reported as relative abundances from mass spectrometry profiling, and dietary PUFA intake was derived from food frequency questionnaire responses. Associations between PUFA and outcomes, including asthma and/or recurrent wheeze, allergic sensitization, and total IgE at age 3 years, were evaluated in adjusted regression models. Additional regression models analyzed the combined effects of antenatal vitamin D and early childhood PUFA on outcomes.

RESULTS

Total, omega-3, and omega-6 plasma PUFA relative abundances were significantly (P < .05) inversely associated with both asthma and/or recurrent wheeze and allergic sensitization. Likewise, dietary PUFA intake was inversely associated with asthma and/or recurrent wheeze (P < .05 for omega-6 PUFA only). For both dietary and plasma measures of total, omega-3, and omega-6 PUFAs, inverse associations with outcomes were strongest among subjects with both high umbilical cord blood 25-hydroxyvitamin D and high PUFA at age 3 years.

CONCLUSIONS

PUFA dietary intake and plasma levels are inversely associated with asthma and/or recurrent wheeze and atopy at age 3 years. Antenatal vitamin D could modulate the effect of early childhood PUFA on risk of asthma and allergy.

Polyunsaturated fatty acids in plasma at 8 years and subsequent allergic disease

BACKGROUND

Polyunsaturated fatty acids (PUFAs) are hypothesized to modulate the risk of allergic disease. However, evidence from previous studies is inconclusive, and limited longitudinal data exist using circulating biomarkers of PUFA intake and metabolism.

OBJECTIVE

We aimed to investigate associations between n-3 and n-6 PUFAs at age 8 years and asthma, rhinitis, and aeroallergen sensitization at age 16 years.

METHODS

Proportions of n-3 PUFAs (very long-chain n-3 [VLC n-3; sum of eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid] and α-linolenic acid) and n-6 PUFAs (linoleic acid and arachidonic acid [AA]) in blood samples at age 8 years were measured for 940 children from the prospective Swedish birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiology). Allergic disease phenotypes were defined by using questionnaires and IgE measures at the ages of 8 and 16 years. Logistic regression was used to examine potential associations.

RESULTS

A higher proportion of total VLC n-3 PUFAs in plasma at age 8 years was associated with a reduced risk of prevalent asthma, rhinitis, and aeroallergen sensitization at age 16 years and with incidence of asthma between 8 and 16 years (adjusted odds ratio, 0.67; 95% CI, 0.47-0.94). AA was associated with a reduced risk of asthma, aeroallergen sensitization, and allergic rhinitis. The findings were most evident for allergic phenotypes of asthma and rhinitis. Additionally, AA was associated with an increased probability of asthma and rhinitis remission between 8 and 16 years of age.

CONCLUSION

Higher proportions of certain VLC n-3 and very long-chain n-6 PUFAs in plasma phospholipids at age 8 years were associated with a reduced risk of allergic disease at age 16 years.

Combinations of distinct long-chain polyunsaturated fatty acid species for improved dietary treatment against allergic bronchial asthma

Allergic bronchial asthma is a chronic inflammatory disease of the airways with an increasing incidence in Western societies. Exposure to allergens provokes recurrent attacks of breathlessness, airway hyperreactivity, wheezing, and coughing. For the early phase and milder forms of allergic asthma, dietary supplementation with long-chain polyunsaturated fatty acids (LCPUFA), predominantly fish oil-associated eicosapentaenoic (C20:5 ω-3) and docosahexaenoic acid (C22:6 ω-3), and distinct crop oil-derived fatty acids might provide a sustainable treatment strategy, as discussed in several studies. In addition to immune-controlling prostaglandins, leukotrienes, and thromboxanes, specialized proresolving mediators, such as lipoxins, resolvins, protectins, and maresins, are metabolized from different LCPUFA, which actively resolve inflammation. The aim of this review was to discuss the possible synergistic effects of ω-3 and ω-6 LCPUFA combinations concerning rebuilding fatty acid homeostasis in cellular membranes, modifying eicosanoid metabolic pathways, controlling inflammatory processes by focusing on resolving inflammation in the bronchoalveolar system on the cellular level, and helping to control clinical symptoms in bronchial asthma.

Prevalence and association of asthma and allergic sensitization with dietary factors in schoolchildren: data from the french six cities study

Background

The prevalence of asthma and allergy has recently risen among children. This increase in prevalence might be related to various factors, particularly diet. The aim of this study is to assess the prevalence and association of asthma and allergic sensitization with dietary factors in the French Six Cities Study.

Methods

Cross-sectional studies were performed among 7432 schoolchildren aged 9–11 years in Bordeaux, Clermont-Ferrand, Créteil, Marseille, Reims, and Strasbourg. Parental questionnaires, based on the International Study on Asthma and Allergies in Childhood (ISAAC), were used to collect information on allergic diseases and potential exposure factors including a food frequency questionnaire to evaluate dietary habits. Skin prick testing to common allergens for allergic sensitization and bronchial hyper-responsiveness (BHR) testing to exercise were performed. Confounders control was performed with multiple logistic regressions.

Results

Asthma symptoms, asthma and allergic sensitization were more prevalent in boys than in girls and were more prevalent in the South than in the North of France. After adjustment for confounders, fruit juice intake was associated with a low prevalence of lifetime asthma (ORa [95 % CI]; 0.73 [0.56–0.97]), butter intake was positively associated with atopic wheeze (1.48 [1.07–2.05]) and having lunch at the canteen 1–2 times/week compared to never or occasionally was associated with a lower prevalence of past year wheeze (0.71 [0.52–0.96]), lifetime asthma (0.76 [0.60–0.96]) and allergic sensitization (0.80 [0.67–0.95]). Meat intake was inversely related to past year wheeze among atopic children (0.68 [0.50–0.98]) while fast food consumption and butter intake were associated with an increase prevalence of asthma (2.39 [1.47–3.93] and 1.51 [1.17–2.00] respectively). Fish intake was associated with a lower prevalence of asthma among non-atopic children (0.61 [0.43–0.87]. None of the dietary factors was associated with BHR.

Conclusions

Diet is associated with wheeze, asthma and allergic sensitization but not with BHR in children. These results provide further evidence that adherence to a healthy diet including fruits, meat and fish seems to have a protective effect on asthma and allergy in childhood. However, prospective and experimental studies are needed to provide causal evidence concerning the effect of diet on asthma and atopy.

Paucity of evidence for a relationship between long-chain omega-3 fatty acid intake and chronic obstructive pulmonary disease: a systematic review

CONTEXT

The anti-inflammatory activity of long-chain n-3 polyunsaturated fatty acids (PUFAs) has been established in several chronic inflammatory diseases but has yet to be demonstrated in inflammatory lung diseases such as chronic obstructive pulmonary disease (COPD).

OBJECTIVE

The aim of this systematic review was to investigate, using PRISMA guidelines, the relationship between the intake of long-chain n-3 PUFAs and the prevalence, severity, and health outcomes of COPD.

DATA SOURCES

Eight health databases and the World Health Organization's international clinical trial registry were searched for relevant studies.

STUDY SELECTION

Experimental or observational studies that were published in English and that assessed long-chain n-3 PUFA intake (by determining habitual consumption and/or tissue levels) in adults with COPD were included.

DATA EXTRACTION

Publication demographics, participant characteristics, type of intervention or exposure, long-chain n-3 PUFA intake, pulmonary function, COPD mortality, and COPD severity were independently extracted from each article by 2 authors using a prospectively designed data extraction tool.

DATA SYNTHESIS

All 11 of the studies included in the review were observational. Approximately equal numbers of studies reported significant (n = 6, 5 inverse) relationships or no significant relationships (n = 5) between either consumption of long-chain n-3 PUFAs or levels of long-chain n-3 PUFAS in tissue and a COPD outcome.

CONCLUSIONS

Current evidence of a relationship between long-chain n-3 PUFA intake and COPD is limited and conflicting, with studies having wide methodological variation.

REGISTRATION NUMBER

PROSPERO 2013:CRD42013004085.

Risk factors affecting asthma prevalence in adolescents living in Istanbul, Turkey

BACKGROUND

Asthma is one of the most important diseases of childhood. The aim of this study was to evaluate the prevalence of asthma symptoms and risk factors affecting asthma.

METHODS

In a cross-sectional study design, 9991 children, aged 13-14 years in 61 primary schools in 32 districts of Istanbul were evaluated. Asthma prevalence among the children was assessed using the ISAAC protocol.

RESULTS

In our study, a total of 10,894 questionnaires were distributed to 13-14 years old children, and of these 9991 questionnaires were suitable for analysis with an overall response rate of 91.7%. The rates of wheeze ever, wheezing in last 12 months and lifetime doctor diagnosed asthma prevalence were 17.4%, 9.0%, and 11.8%, respectively. There were 4746 boys (47.9%) and 5166 girls (52.1%) with M/F ratio of 0.92. Atopic family history, fewer than three siblings living at home, tonsillectomy or adenoidectomy history, consumption of fermented foods, mixed pickles, margarine and meat were found to be associated with an increased asthma risk. Use of paracetamol in the last 12 months, consumption of fruit and animal fats acted as a protective factor against asthma. The Mediterranean-style diet was not associated with the prevalence of asthma.

CONCLUSIONS

Lifetime doctor diagnosed asthma prevalence was found to be 11.8% in 13-14 year olds. History of tonsillectomy and/or adenoidectomy and consumption of fermented foods, mixed pickles, margarine and meat may increase the symptoms of asthma. Usage of paracetamol and consumption of animal fats may be investigated as a protective factor against asthma.

Prevention of asthma: where are we in the 21st century?

Asthma is the most common chronic disease of childhood and, in the latter part of the 20th century, reached epidemic proportions. Asthma is generally believed to result from gene-environment interactions. There is consensus that a 'window of opportunity' exists during pregnancy and early in life when environmental factors may influence its development. We review multiple environmental, biologic and sociologic factors that may be important in the development of asthma. Meta-analyses of studies have demonstrated that multifaceted interventions are required in order to develop asthma prevention. Multifaceted allergen reduction studies have shown clinical benefits. Asthma represents a dysfunctional interaction with our genes and the environment to which they are exposed, especially in fetal and early infant life. The increasing prevalence of asthma also may be an indication of increased population risk for the development of other chronic non-communicable autoimmune diseases. This review will focus on the factors which may be important in the primary prevention of asthma. Better understanding of the complex gene-environment interactions involved in the development of asthma will provide insight into personalized interventions for asthma prevention.

Arachidonic acid intake and asthma risk in children and adults: a systematic review of observational studies

The effect of arachidonic acid (ARA) intake on asthma risk is unclear. The objective of the present review was to systematically evaluate available observational studies on the relationship between ARA exposure and asthma risk in children and adults. A PubMed search was conducted on 22 October 2013 and seventy-three publications were checked against predefined criteria for eligibility. To identify additional eligible publications, potentially relevant articles were searched from bibliographies of articles on ARA and asthma. A total of 2924 citations were scrutinised. Finally, fourteen articles were included. A quality assessment was conducted based on the reporting and methodological quality. A meta-analysis was not conducted; therefore, a qualitative assessment is presented. Three high-, two medium- and ten low-quality studies were reviewed. Eleven studies, including two high- and two medium-quality studies, did not find a significant association between ARA exposure and asthma risk. In contrast, one high-quality study indicated a significant trend toward reducing asthma risk in children with decreasing maternal ARA intake (P trend = 0·025), and one low-quality study reported a significant trend of increasing asthma risk with higher blood ARA levels (P trend = 0·007). In two low-quality studies, asthma patients had significantly lower blood ARA levels than controls (both P < 0·05). These studies did not sufficiently demonstrate any relationships between ARA exposure and asthma risk because of the limited number of studies and their methodological limitations. They seem to suggest that ARA exposure is not consistently associated with asthma risk. Nevertheless, further evidence is required to prove or disprove the association.

Phytochemical profiles and biological activity evaluation of Zanthoxylum bungeanum Maxim seed against asthma in murine models

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum bungeanum Maxim seed (ZBMS) has been used in Traditional Chinese Medicine (TCM) as an ingredient of polyherbal formulations for the treatment of inflammation and asthma. The aim of this study was to analyze the major composition and to evaluate the anti-asthma activity of ZBMS.

MATERIALS AND METHODS

Some murine models including acetylcholine/histamine-induced asthma, ovalbumin-induced airway inflammation, ear edema and toe swelling measurement, citric acid-induced cough, and anti-stress abilities were investigated to fully study the anti-asthma activity of ZBMS.GC chromatography was also performed to analyze the major fatty acid composition of ZBMS.

RESULTS

The results demonstrated that the major fatty acid composition of ZBMS includes oleic acid (20.15%), linoleic acid (26.54%), and α-linolenic acid (30.57%), which was the leading component of ZBMS, and that the total fatty acid content of ZBMS was 77.27%. The murine models demonstrated that ZBMS displays a protective effect on guinea pig sensitization, a dose-dependent inhibition of the increases in RL and decreases in Cdyn, which resulted in the relief of auricle edema and toe swelling in mice and anti-stress activity.

CONCLUSION

Our results validate the traditional use of ZBMS for the treatment of asthma and other inflammatory joint disorders, and suggest that ZBMS has potential as a new therapeutic agent for asthma management.

Fatty acids, inflammation, and asthma

Fatty acids and consequently diet play an essential role in the formation of inflammatory mediators involved in the pathogenesis of asthma. Because intake variations of omega-6 (n-6) and omega-3 (n-3) fatty acids ultimately determine cell membrane incorporation, changes in diet have the potential to modify downstream production of inflammatory mediators derived from these compounds. It has long been hypothesized that decreasing the n-6/n-3 ratio could reduce the production of more proinflammatory mediators while increasing the formation of downstream metabolites that can serve to limit or resolve inflammation. In turn, these changes would result in improved asthma outcomes or would lower the risk for asthma incidence. This review will focus on the role of fatty acid inflammatory and resolving mediators and will summarize the clinical and epidemiologic data on how diet and obesity alter fatty acid profiles that can contribute to asthma.

Diet and allergic diseases among population aged 0 to 18 years: myth or reality?

Allergic diseases are an important health problem. However, epidemiological studies concerning childhood diet-related allergic diseases are scarce. This review examines published articles dealing with diet, dietary patterns and nutrition in relation with allergic diseases among population aged 0 to 18 years. Studies and trials were identified using MEDLINE/PubMed and Cochrane Database of Systematic Reviews and were limited to those published in English or French from 1992 until 2012. This manuscript also reviews the evidence for maternal diet during pregnancy and diet during early childhood and their association with childhood atopic diseases, taking into account the methodology used to evaluate dietary patterns. The evidence reviewed is derived from large epidemiological studies exploring the effects of different food categories on asthma, atopic dermatitis, and allergic rhinitis in children. Overall, maternal diet during pregnancy and a childhood diet rich in antioxidants and omega-3 fatty acids are considered as healthy diets that could be protective for allergic diseases in childhood.

Comparison of physical activity energy expenditure in Japanese adolescents assessed by EW4800P triaxial accelerometry and the doubly labelled water method

The present study compared the accuracy of triaxial accelerometry and the doubly labelled water (DLW) method for measuring physical activity (PA) in Japanese adolescents. A total of sixty adolescents aged 12–15 years were analysed. The total energy expenditure (TEE) was measured over 7 d by the DLW method and with an EW4800P triaxial accelerometer (Panasonic Corporation). The measured (RMRm) and predicted RMR (RMRp) were 5·7 (sd 0·9) and 6·0 (sd 1·0) MJ/d, respectively. TEE measured by the DLW method and accelerometry using RMRm or RMRp were 11·0 (sd 2·6), 10·3 (sd 1·9), and 10·7 (sd 2·1) MJ/d, respectively. The PA levels (PAL) measured by the DLW method using RMRm or RMRp were 1·97 (sd 0·31) and 1·94 (sd 0·31) in subjects who exercised, and 1·85 (sd 0·27) and 1·74 (sd 0·29) in subjects who did not exercise. The percentage of body fat correlated significantly with the percentage difference between RMRmv. RMRp, TEE, PA energy expenditure (PAEE) and PAL using RMRp, and PAL using RMRm assessed by the DLW method and accelerometry. The present data showed that while accelerometry estimated TEE accurately, it did not provide the precise measurement of PAEE and PAL. The error in accelerometry was attributed to the prediction error of RMR and assessment in exercise.

Influence and mechanisms of maternal and infant diets on the development of childhood asthma

Perinatal nutrition has been implicated in the programming of diseases in children and adults. The prevalence of asthma has dramatically increased in the past few decades, particularly in children. This suggests that the perinatal environment, including maternal and infant diets, may be involved in the increase in the prevalence of asthma. Recent studies have demonstrated that certain maternal and infant diets have a protective or augmentative effect on the development of asthma. Maternal diets with higher vitamin D, vitamin E, or/and probiotics are related to asthma prevention. Infants with breast feeding for at least 4 months and/or complementary diets between 4 and 6 months may have regulatory effects on the prevention of asthma. In summary, diets may have epigenetic or immune regulatory effects on the promotion or prevention of asthma. This article analyzes recent reports on the potential mechanism and mechanism-driven early prevention of childhood asthma by modification of maternal and infant diets.

Associations of intake of antioxidant vitamins and fatty acids with asthma in pre-school children

OBJECTIVE

Increasing childhood asthma rates may be due to changing dietary lifestyle. We investigated the association of dietary intake of antioxidant vitamins and fatty acids with asthma in Japanese pre-school children.

DESIGN

Cross-sectional study.

SETTING

School-based survey on lifestyle/diet and health status in children in Japan.

SUBJECTS

Parents of 452 children aged 3-6 years completed a questionnaire on the children's and parents’ lifestyle and demographics. Children were classified into asthma cases and non-asthma cases in accordance with the ATS-DLD(American Thoracic Society and Division of Lung Diseases of the National Heart, Lung, and Blood Institute) questionnaire. Children's diet was assessed using a 3 d dietary record completed by parents. Children's age, sex, BMI, history of food allergy, maternal age, parental history of allergy, maternal education,family size and second-hand smoking were included as covariates. Logistic regression models were used to examine the association between children's diet and asthma.

RESULTS

Compared with children with the lowest intake tertile for vitamin C and vitamin E, those in the highest were significantly inversely associated with asthma; adjusted OR (95% CI) were 0?35 (0?14, 0?88) and 0?32 (0?12, 0?85),respectively. A statistically significant trend was also observed. Fruit intake showed an inverse but insignificant association with asthma. There were no associations of any type of fatty acids with asthma.

CONCLUSIONS

These data suggest that children with high intakes of vitamins C and E may be associated with a reduced prevalence of asthma.

Rising prevalence of asthma is sex-specific in a US farming population

BACKGROUND

Asthma prevalence is increasing worldwide in most populations, likely due to a combination of heritable factors and environmental changes. Curiously, however, some European farming populations are protected from asthma, which has been attributed to their traditional lifestyles and farming practices.

OBJECTIVE

We conducted population-based studies of asthma and atopy in the Hutterites of South Dakota, a communal farming population, to assess temporal trends in asthma and atopy prevalence and describe the risk factors for asthma.

METHODS

We studied 1325 Hutterites (ages 6-91 years) at 2 time points from 1996 to 1997 and from 2006 to 2009 by using asthma questionnaires, pulmonary function and methacholine bronchoprovocation tests, and measures of atopy.

RESULTS

The overall prevalence of asthma increased over the 10- to 13-year study period (7.5%-11.1%, P = .049), whereas the overall prevalence of atopy did not change (45.0%-44.8%, P = .95). Surprisingly, the rise in asthma was only among females (5.8%-11.2%, P = .02); the prevalence among males remained largely unchanged (9.4%-10.9%, P = .57). Atopy, which was not associated with asthma risk in 1996 to 1997, was the strongest risk factor for asthma among Hutterites studied in 2006 to 2009 (P = .003).

CONCLUSIONS

Asthma has increased over a 10- to 13-year period among Hutterite females and atopy has become a significant risk factor for asthma, suggesting a change in environmental exposures that are either sex limited or that elicit a sex-specific response.

Polyunsaturated fatty acid intake and prevalence of eczema and rhinoconjunctivitis in Japanese children: the Ryukyus Child Health Study

Background

The recent increase in the prevalence of allergic disorders might be a consequence of increased intake of n-6 polyunsaturated fatty acids (PUFAs) and reduced intake of n-3 PUFAs. The current cross-sectional study examined the association between intake levels and the prevalence of eczema and rhinoconjunctivitis in Japanese children.

Methods

Subjects were 23,388 schoolchildren aged 6-15 years residing in Okinawa. The presence of eczema and/or rhinoconjunctivitis was determined according to the criteria of the International Study of Asthma and Allergies in Childhood. A brief diet history questionnaire for children and adolescents was administered to acquire information on dietary factors. Adjustment was made for age, sex, residential municipality, number of siblings, smoking in the household, body mass index, paternal and maternal history of allergic diseases, and paternal and maternal educational level.

Results

The prevalences of eczema and rhinoconjunctivitis in the previous 12 months were 7.0% and 8.0%, respectively. Consumption of PUFAs, n-3 PUFAs, α-linolenic acid, n-6 PUFAs, and linoleic acid was positively associated with the prevalence of eczema: the adjusted odds ratios (ORs) between extreme quintiles (95% confidence intervals [CIs], P for trend) were 1.26 (1.07-1.48, 0.04), 1.31 (1.11-1.54, 0.009), 1.31 (1.12-1.55, 0.003), 1.26 (1.07-1.48, 0.01), and 1.27 (1.08-1.49, 0.01), respectively. Arachidonic acid intake was independently inversely related to eczema: the adjusted OR between extreme quintiles was 0.81 (0.69-0.95, 0.0008). Eczema was not associated with eicosapentaenoic or docosahexaenoic acid intake, or with the ratio of n-3 to n-6 PUFA intake. Only arachidonic acid intake was statistically significantly related to the prevalence of rhinoconjunctivitis, showing a clear inverse linear trend: the adjusted OR between extreme quintiles was 0.86 (0.74-0.997, 0.03).

Conclusions

Consumption of n-3 and n-6 PUFAs, especially α-linolenic acid and linoleic acid, may be positively associated with eczema. Arachidonic acid intake may be inversely related to eczema and rhinoconjunctivitis.

Fatty acid intakes of children and adolescents are not in line with the dietary intake recommendations for future cardiovascular health: a systematic review of dietary intake data from thirty countries

Fatty acid composition of the diet may influence cardiovascular risk from early childhood onwards. The objective of the present study was to perform a systematic review of dietary fat and fatty acid intakes in children and adolescents from different countries around the world and compare these with the population nutrient intake goals for prevention of chronic diseases as defined by the WHO (2003). Data on fat and fatty acid intake were mainly collected from national dietary surveys and from population studies all published during or after 1995. These were identified by searching PubMed, and through nutritionists at local Unilever offices in different countries. Fatty acid intake data from thirty countries mainly from developed countries were included. In twenty-eight of the thirty countries, mean SFA intakes were higher than the recommended maximum of 10 % energy, whereas in twenty-one out of thirty countries mean PUFA intakes were below recommended (6–10 % energy). More and better intake data are needed, in particular for developing regions of the world, and future research should determine the extent to which improvement of dietary fatty acid intake in childhood translates into lower CHD risk in later life. Despite these limitations, the available data clearly indicate that in the majority of the countries providing data on fatty acid intake, less than half of the children and adolescents meet the SFA and PUFA intake goals that are recommended for the prevention of chronic diseases.

Diet and asthma: nutrition implications from prevention to treatment

Asthma is characterized by lung airway inflammation initiated and perpetuated by an inappropriate immune response, increased airway responsiveness, and variable airflow obstruction. In Western countries there has been a marked increase in asthma prevalence such that it has become a public health concern. It has been hypothesized that the increase may be due to changing antioxidant intake, increasing dietary ratio of n-6:n-3 polyunsaturated fatty acids (PUFA), and vitamin D deficiency (and supplementation). Observational studies have reported associations between asthma and dietary antioxidants (vitamin E, vitamin C, carotenoids, selenium, polyphenols, and fruit), PUFA, and vitamin D. However, supplementing the diets of adults with asthma with antioxidants and n-3 PUFA has minimal, if any, clinical benefit. Currently there is insufficient evidence to support the use of nutrient supplements to complement conventional treatment; however, results of ongoing studies are awaited, and additional research is required, particularly in children. Interest in the potential of dietary intervention during pregnancy to reduce the likelihood of childhood asthma has increased. A small number of cohort studies have highlighted associations between childhood asthma and reduced maternal intake of some nutrients (vitamin E, vitamin D, selenium, zinc, and PUFA) during pregnancy. Although vitamin D intervention studies during pregnancy are ongoing and two intervention studies suggest that dietary PUFA manipulation during pregnancy may be advantageous, further trials are needed to establish if modification of maternal nutrient intake during pregnancy can be used as a healthy, low cost, public health measure to reduce the prevalence of childhood asthma.

Dietary folate, riboflavin, vitamin B-6, and vitamin B-12 and depressive symptoms in early adolescence: the Ryukyus Child Health Study

OBJECTIVE

To examine the association between dietary folate, riboflavin, vitamin B-6, and vitamin B-12 and depressive symptoms in a group of adolescents.

METHODS

This cross-sectional study, conducted in all public junior high schools in Naha City and Nago City, Okinawa, Japan, included 3,067 boys and 3,450 girls aged 12 years to 15 years (52.3% of eligible sample). Dietary intake was assessed using a validated, self-administered diet history questionnaire. Depressive symptoms were defined as present when participants had a Center for Epidemiologic Studies Depression Scale score of ≥16.

RESULTS

The prevalence of depressive symptoms was 22.5% for boys and 31.2% for girls. Folate intake was inversely associated with depressive symptoms in both boys (adjusted odds ratio (OR) [95% confidence interval (CI)] in the highest (compared with the lowest) quintile, 0.60 [0.45, 0.79]; p for trend = .002) and girls (OR [95% CI], 0.61 [0.48, 0.77]; p for trend = <.001). Vitamin B-6 intake was inversely associated with depressive symptoms in both boys (OR [95% CI], 0.73 [0.54, 0.98]; p for trend = .02) and girls (OR [95% CI], 0.72 [0.56, 0.92]; p for trend = .002). Riboflavin intake was inversely associated with depressive symptoms in girls (OR [95% CI], 0.85 [0.67, 1.08]; p for trend = .03), but not in boys. No clear association was seen between vitamin B-12 intake and depressive symptoms in either sex.

CONCLUSIONS

This study suggests that higher intake of dietary B vitamins, particularly folate and vitamin B-6, is independently associated with a lower prevalence of depressive symptoms in early adolescence.

The effect of prenatal and postnatal dietary exposures on childhood development of atopic disease

PURPOSE OF REVIEW

Prenatal and early life dietary factors may influence asthma and allergic disease development. We review recent studies and consensus statements regarding the effects of prenatal/early life dietary exposures on atopic disease.

RECENT FINDINGS

The American Academy of Pediatrics consensus statement highlighted the inadequacy of evidence for pregnancy antigen avoidance diets or delay of infant complementary foods beyond 4-6 months. Recent studies raise the question of whether early food introduction may promote tolerance, though controlled trials are pending. A recent meta-analysis suggested that antioxidants may protect against the development of atopy. Furthermore, some of the conflicting results on the effects of vitamin E may be related to variability in the isoforms prevalent in local diet. Recent studies of vitamin D similarly suggest that it may be protective, though this remains controversial. Finally, prenatal methyl donor exposure promoted the development of allergy in an animal model.

SUMMARY

There are conflicting data on the effects of most prenatal and early childhood dietary exposures on childhood atopic disease. Longitudinal prenatal/birth cohort studies with prospective measurements and clinical supplementation trials of promising dietary factors will be needed to make reliable recommendations in this vulnerable population of pregnant women and their infants.

Fish and n-3 polyunsaturated fatty acid intake and depressive symptoms: Ryukyus Child Health Study

BACKGROUND

Epidemiologic evidence on the role of fish and long-chain n-3 polyunsaturated fatty acid intake on depression during adolescence is sparse.

OBJECTIVE

We examined the association between fish, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) intake and depressive symptoms in a group of adolescents.

SUBJECTS AND METHOD

This cross-sectional study, conducted in all public junior high schools in Naha City and Nago City, Okinawa, Japan, included 3067 boys and 3450 girls aged 12 to 15 years (52.3% of the eligible sample). Dietary intake was assessed by using a validated, self-administered diet-history questionnaire. Depressive symptoms were defined as present when participants had a Center for Epidemiologic Studies Depression scale score of >or=16.

RESULTS

The prevalence of depressive symptoms was 22.5% for boys and 31.2% for girls. For boys, fish intake was inversely associated with depressive symptoms (adjusted odds ratio [OR] for depressive symptoms in the highest [compared with the lowest] quintile of intake: 0.73 [95% confidence interval (CI): 0.55-0.97]; P for trend=.04). EPA intake showed an inverse association with depressive symptoms (OR: 0.71 [95% CI: 0.54-0.94]; P=.04). DHA intake also showed a similar inverse, albeit nonsignificant, association (OR: 0.79 [95% CI: 0.59-1.05]; P=.11). In addition, intake of EPA plus DHA was inversely associated with depressive symptoms (OR: 0.72 [95% CI: 0.55-0.96]; P=.08). Conversely, no such associations were observed among girls.

CONCLUSIONS

Higher intake of fish, EPA, and DHA was independently associated with a lower prevalence of depressive symptoms in early male, but not female, adolescents.

Fat intake and asthma in Spanish schoolchildren

OBJECTIVES

To study the relationship between lipid, fatty acid and lipid-rich food intake and current asthma in a group of Spanish schoolchildren.

SUBJECTS/METHODS

The subjects of this cross-sectional study were 638 Spanish schoolchildren (8-13 years of age). The weight and height of all the subjects were recorded. A questionnaire, completed by the subjects' parents, was used to obtain personal and health information. Current asthma was established when the children had ever had asthma, if they had been diagnosed with asthma by a doctor and if they had been treated with medications at some time in the previous 12 months. Food intake was monitored using a 3-day food record. All foods consumed were converted into energy and nutrients.

RESULTS

The energy derived from lipids, saturated fatty acids (SFAs) and myristic and palmitic acids was independently associated with current asthma (Odds Ratio (OR) third tertile 2.85 (1.01-8.07) P=0.049, 10.00 (0.89-111.97) P=0.002, 11.21 (1.36-92.24) P=0.002, 7.58 (1.40-41.03) P=0.022, respectively), as was the intake of butter (OR third tertile 2.97 (1.01-8.68) P=0.001). No relationship was seen between this condition and the intake of any other fatty acid, the n-6/n-3 ratio, nor the consumption of margarine, milk products, fish, meat, eggs or vegetable oils.

CONCLUSIONS

Increased intakes of SFAs, myristic and palmitic acids and butter seem to be related to the risk of current asthma in children.

Developments in the field of allergy in 2008 through the eyes of Clinical & Experimental Allergy

In 2008, many thousands of articles were published on the subject of allergic disease with over 200 reviews, editorials and original papers in Clinical & Experimental Allergy alone. These represent a considerable amount of data and even the most avid reader could only hope to assimilate a small fraction of this knowledge. There is therefore a pressing need for the key messages that emerge from a journal such as Clinical & Experimental Allergy to be summarized by experts in the field in a form that highlights the significance of the developments and sets them in the context of important findings in the field published in other journals. This also has the advantage of making connections between new data in conditions such as asthma, where articles often appear in different sections of the journal. As can be seen from this review, the body of work is diverse both in terms of the disease of interest and the discipline that has been used to investigate it. However, taken as a whole, we hope that the reader will gain a flavour of where the field is mature, where there remain controversies and where the cutting edge is leading.

What's new in alternative therapies for asthmatic children?

Nurses require current information about popular complementary and alternative medicine for pediatric asthma. This integrative review searched scientific literature in PubMed and WEB of Science from 2004 to 2009 via key terms: asthma complementary medicine, nursing complementary pediatric asthma, asthma herbal, and herbal pediatric asthma. Nine journal articles met the inclusion criteria of containing data collection and analysis for biologically based therapies for pediatric asthma. Evidenced-based research on this focus topic is still in its initial stages. Two themes of maximizing the diet and augmenting conventional therapy with Traditional Chinese Medicine may serve as conduits of patient education.

Session 1: Allergic disease: Nutrition as a potential determinant of asthma

Asthma is characterised by chronic lung airway inflammation, increased airway responsiveness and variable airflow obstruction. In Westernised countries asthma is a public health concern because of its prevalence, associated ill health and high societal and healthcare costs. In recent decades there has been a marked increase in asthma prevalence, particularly in Westernised countries. It has been proposed that changing diet has contributed to the increase in asthma. Several dietary hypotheses exist; the first relates the increase in asthma to declining dietary antioxidant intake, the second to decreased intake of long-chain n-3 PUFA and increasing intake of n-6 PUFA. Vitamin D supplementation and deficiency have also been hypothesised to have contributed to the increase in asthma. Observational studies have reported associations between asthma and dietary antioxidants (vitamin E, vitamin C, carotenoids, Se, flavonoids, fruit), lipids (PUFA, butter, margarine, fish) and vitamin D. However, supplementing the diets of adults with asthma with antioxidants and lipids has minimal, if any, clinical benefit. There is growing interest in the possibility that childhood asthma is influenced by maternal diet during pregnancy, with studies highlighting associations between childhood asthma and maternal intake of some nutrients (vitamin E, vitamin D, Se, PUFA) during pregnancy. It has been suggested that maternal diet during pregnancy influences fetal airway and/or immune development. Further intervention studies are needed to establish whether modification of maternal nutrient intake during pregnancy can be used as a healthy low-cost public health measure to reduce the prevalence of childhood asthma.

Diet and asthma--can you change what you or your children are by changing what you eat?

In this review we focus on dietary fat content and subsequent effects on asthma. According to the World Health Organisation over 300 million people currently have asthma. The majority of asthma cases are 'extrinsic' and result from inappropriate 'allergic' immune responses to inhaled environmental substances. Whilst some individuals are allergic to particular food components it is becoming clear that the content of the diet can more generally affect the health of the immune system. Components of maternal and early life diets have been reported to influence offspring immune function and asthma. There has been speculation that different types of dietary fat have pro- and anti-inflammatory effects but the results of various studies are contradictory. Asthma and obesity are two conditions that have almost simultaneously reached epidemic levels in some societies. There is evidence that diet-induced obesity alters immune function and there is little doubt that consumption of a high caloric diet with high fat content leads to obesity. However, there is conflicting information over whether and how obesity is linked to asthma in children and adults. Whilst obesity is to be avoided there is accumulating evidence that dietary fat per se does not necessarily predispose towards allergic symptoms.