The relationship of dietary fish intake to level of pulmonary function in the first National Health and Nutrition Survey (NHANES I)

Nutriepigenomics and chronic obstructive pulmonary disease: potential role of dietary and epigenetics factors in disease development and management

Over recent decades, a number of studies have revealed the possible role of different types of diets, as well as the nutritional elements they are made up of, in the pathogenesis of chronic obstructive pulmonary disease (COPD). To date, dietary factors have been identified to play a role in the prevention of COPD, with evidence from antioxidant nutrients, vitamins, and fiber intake. Additionally, certain dietary patterns such as the Mediterranean diet, together with other Western diets, provide evidence of the influence on COPD development, promoting lung health through nutritional approaches, and giving us an opportunity for intervention. The effect of diet on COPD is conveyed by 3 mechanisms: regulation of inflammation, oxidative stress, and carbon dioxide produced/oxygen intake. Current advances have begun to highlight the possible role of diet in modifying gene expression in certain individuals that predisposes them to COPD through epigenetic modifications. The relation between dietary intake and epigenetic factors has therefore outlined nutriepigenomics as a possible missing link in the relation between environmental exposure to smoke and the appearance of a subsequent chronic bronchial obstruction. This review summarizes the evidence regarding the influence of dietary patterns and nutrients and epigenetic regulatory mechanisms on COPD development and prevention with the aim of encouraging clinical research on the impact of dietary modifications on COPD-related clinical outcomes. This review highlights the importance of proposing and carrying out future studies focused on the modulating effects of certain nutrients on epigenetic changes in patients with specific COPD phenotypes (bronchiectasis, emphysema, asthma/COPD, chronic bronchitis), and their individual responses to cigarette smoking, environmental pollution, or other noxious particles. The objectives of these future studies must be directed to the development of novel therapeutic approaches and personalized management of COPD.

Nutrition as a modifiable factor in the onset and progression of pulmonary function impairment in COPD: a systematic review

CONTEXT

Chronic obstructive lung disease (COPD) is a progressive lung disease characterized by persistent airflow limitation. An increasing amount of evidence suggests an effect of dietary quality on the risk of COPD in the general population and pulmonary function decline in patients with COPD.

OBJECTIVE

The association of dietary intake and nutrient status with COPD risk and onset, as well as pulmonary function decline (change in forced expiratory volume in 1 second, forced vital capacity, or the ratio of the former to the latter) in patients with COPD was investigated in this systematic review.

DATA SOURCES

The PubMed database was searched by combining terms of pulmonary function or COPD with diet, nutrient status, or nutritional supplementation.

DATA EXTRACTION

Original studies and systematic reviews and meta-analyses were included. Articles obtained were independently screened for relevance on the bases of title and abstract by 2 researchers. Eventually, 89 articles were included in the analysis.

RESULTS

The unhealthy Western-style diet is associated with an increased risk of COPD and an accelerated decline of pulmonary function. Intake of fruit, vegetables, dietary fibers, vitamins C and E, polyphenols, and β-carotene were individually associated with lower COPD risk, whereas consumption of processed meat was associated with higher COPD risk. Data on the effect of dietary quality on pulmonary function decline in patients with COPD are limited and inconsistent. Strong evidence for beneficial effects on pulmonary function decline was found only for vitamin D supplementation.

CONCLUSION

Considering the increasing burden of COPD, more attention should be given to dietary quality as a modifiable factor in disease development and progression in patients with COPD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021240183.

Serum selenium levels and asthma among seafood processing workers in Greenland

Selenium levels in the Inuit population of Greenland have been declining during the last decades. The association between Selenium and asthma has been investigated previously, but with conflicting results. The objective was to measure human serum Se (s-Se) in Greenlandic seafood processing workers, to compare with levels recorded in previous decades and to establish if s-Se is associated with asthma or lung function. Data, including questionnaire answers, spirometry, skin-prick test and s-Se from 324 seafood processing workers in Greenland were collected during 2016-2017. Mean s-Se values were compared by t-test and one-way ANOVA. Associations between s-Se and asthma, symptoms from the lower airways at work and lung function were assessed using linear regression. The mean s-Se was 96.2 µg/L. S-Se was higher among non-smokers and workers living in settlements. Workers with asthma did not have s-Se levels significantly different from those of non-asthmatics. We found a positive association between s-Se levels and FEV₁ values. Selenium levels appear to continue declining in Greenland, presumably because of a more Westernised lifestyle. The health effects of declining Selenium levels remain unclear. We did not establish an association between s-Se and asthma, but we did record a positive association between s-Se and FEV₁.

Relationship between dietary patterns and COPD: a systematic review and meta-analysis

Background

Findings from previous studies reporting on the associations between chronic obstructive pulmonary disease (COPD) and various dietary patterns have been inconsistent. This review aims to summarise the evidence on the strength of the association between dietary patterns and the prevalence and incidence of COPD.

Methods

We conducted a comprehensive search of seven databases between 1 January 1980 and 30 November 2019. Two reviewers independently reviewed each manuscript through the screening, selection, data extraction and quality assessment stages. Data from eight observational studies that met the inclusion criteria were extracted and random-effects meta-analysis was subsequently conducted.

Results

Eight observational studies (all eight reporting on healthy dietary patterns and three on unhealthy dietary patterns) met the inclusion criteria and data were extracted to include in the meta-analysis. Consumption of a healthy dietary pattern was associated with a lower risk of COPD (pooled OR 0.88, 95% CI 0.82–0.94). Consumption of unhealthy dietary patterns was associated with a higher risk of COPD (OR 1.22, 95% CI 0.84–1.76); however, the results were not statistically significant and had high heterogeneity (I²=91%).

Conclusion

Our results suggests that healthy dietary patterns are associated with a lower prevalence of COPD, while unhealthy dietary patterns are not. More studies, particularly adequately powered longitudinal studies, are needed to further elucidate the effects of healthy and unhealthy dietary patterns on risk of COPD.

This review suggests that individuals with healthy dietary pattern have lower risk of chronic obstructive pulmonary diseasehttp://bit.ly/331PVJ1

Lipid mediators and asthma: Scope of therapeutics

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

Are Dietary Factors Associated with Lung Function in Canadian Adults?

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

Activation of Resolution Pathways to Prevent and Fight Chronic Inflammation: Lessons From Asthma and Inflammatory Bowel Disease

Formerly considered as a passive process, the resolution of acute inflammation is now recognized as an active host response, with a cascade of coordinated cellular and molecular events that promotes termination of the inflammatory response and initiates tissue repair and healing. In a state of immune fitness, the resolution of inflammation is contained in time and space enabling the restoration of tissue homeostasis. There is increasing evidence that poor and/or inappropriate resolution of inflammation participates in the pathogenesis of chronic inflammatory diseases, extending in time the actions of pro-inflammatory mechanisms, and responsible in the long run for excessive tissue damage and pathology. In this review, we will focus on how resolution can be the target for therapy in "Th1/Th17 cell-driven" immune diseases and "Th2 cell-driven" immune diseases, with inflammatory bowel diseases (IBD) and asthma, as relevant examples. We describe the main cells and mediators stimulating the resolution of inflammation and discuss how pharmacological and dietary interventions but also life style factors, physical and psychological conditions, might influence the resolution phase. A better understanding of the impact of endogenous and exogenous factors on the resolution of inflammation might open a whole area in the development of personalized therapies in non-resolving chronic inflammatory diseases.

Dietary Patterns and Prevalence of Post-bronchodilator Airway Obstruction in Dairy Farmers Exposed to Organic Dusts

Exposure to organic dusts is an independent causative factor of chronic obstructive pulmonary disease (COPD). Unhealthy dietary patterns have been associated with poor lung function in smokers. This study investigated whether dietary patterns were associated with post-bronchodilator airway obstruction, a hallmark of COPD, in dairy farmers exposed to organic dusts. All subjects were identified by screening programs and patients with airflow obstruction were matched with subjects with normal spirometry. Six groups were compared, defined by their exposures (non-smoking dairy farmers, smokers ≥ 10 pack-years with no occupational exposure, and smoking dairy farmers) and the presence or absence of post-bronchodilator airflow obstruction, resulting in 321 study subjects. The Alternative Healthy Eating Index (AHEI) score was calculated based on an adapted food frequency questionnaire. Mean total AHEI scores were similar in all groups. Comparison between smokers with post-bronchodilator airway obstruction and subjects with post-bronchodilator airway obstruction related to occupational exposure found minimal differences in dietary patterns: dairy farmers had lower scores for the ratio of white to red meat and higher scores for cereal fiber consumption. As in previous studies, smokers with post-bronchodilator airway obstruction exhibited higher lipid intakes and lower carbohydrate intakes than their counterparts with normal spirometry. No evidence of any meaningful difference in dietary patterns was found between subjects with post-bronchodilator airway obstruction detected by screening and healthy controls, either in dairy farmers or in smokers with no occupational exposure.

Role of Diet in Chronic Obstructive Pulmonary Disease Prevention and Treatment

Chronic obstructive pulmonary disease is one of the leading causes of morbidity and mortality worldwide and a growing healthcare problem. Identification of modifiable risk factors for prevention and treatment of COPD is urgent, and the scientific community has begun to pay close attention to diet as an integral part of COPD management, from prevention to treatment. This review summarizes the evidence from observational and clinical studies regarding the impact of nutrients and dietary patterns on lung function and COPD development, progression, and outcomes, with highlights on potential mechanisms of action. Several dietary options can be considered in terms of COPD prevention and/or progression. Although definitive data are lacking, the available scientific evidence indicates that some foods and nutrients, especially those nutraceuticals endowed with antioxidant and anti-inflammatory properties and when consumed in combinations in the form of balanced dietary patterns, are associated with better pulmonary function, less lung function decline, and reduced risk of COPD. Knowledge of dietary influences on COPD may provide health professionals with an evidence-based lifestyle approach to better counsel patients toward improved pulmonary health.

Saturated Fat Intake Is Associated with Lung Function in Individuals with Airflow Obstruction: Results from NHANES 2007⁻2012

Nutritional status is a well-recognized prognostic indicator in chronic obstructive pulmonary disease (COPD); however, very little is known about the relationship between lung function and saturated fat intake. We used data from the cross-sectional National Health and Nutrition Examination Surveys (NHANES) to assess the relationship between saturated fatty acid (SFA) intake and lung function in the general US adult population. Adults in NHANES (2007⁻2012) with pre-bronchodilator spirometry measurements and dietary SFA intake were included. Primary outcomes were lung function including forced expiratory volume in one second (FEV₁)_, FEV₁, forced vital capacity (FVC), FEV₁/FVC ratio, percent predicted FEV₁ and percent predicted FVC. Multivariable regression models in the general population as well as those with spirometry-defined airflow obstruction were used to assess the relationship between lung function measurements and dietary SFA intake after adjustment for confounders. 11,180 eligible participants were included in this study. Univariate analysis revealed a statistically significant positive association between total SFA intake and lung function outcomes; however, these relationships were attenuated after adjustment for covariates. A secondary analysis of individuals with spirometry-defined airflow obstruction (FEV₁/FVC < 0.7) revealed that a lower intake of SFA was associated with reduced FEV₁ (β = -126.4, p = 0.04 for quartile 1 vs. quartile 4), FVC (β = -165.8. p = 0.01 for quartile 1 vs. quartile 4), and percent predicted FVC (β = -3.3. p = 0.04 for quartile 1 vs. quartile 4), after adjustment for relevant confounders. No associations were observed for the FEV₁/FVC ratio and percent predicted FEV₁. It is possible that characteristics such as food source and fatty acid chain length may influence associations between saturated fatty acid intake and health outcomes.

Dietary intake of fatty acids and its relationship with FEV1/FVC in patients with chronic obstructive pulmonary disease

BACKGROUND & AIMS

The deterioration of pulmonary function has been associated with increased levels of systemic inflammation that can be stimulated by consumption of saturated fatty acids and trans fats. We hypothesized that fatty acids intake impact on pulmonary function. However, evidence about the impact of different types of fatty acids on pulmonary function in patients with chronic obstructive pulmonary disease (COPD) is limited and heterogeneous. The aim of this study was to evaluate the association between intake of fatty acids and pulmonary function in patients with COPD.

METHODS

Cross sectional study of patients diagnosed with COPD. The relationship between consumption of fatty acids and the FEV₁/FVC ratio obtained by spirometry was assessed. Patients with exacerbations during the prior 2 months, diagnosis of asthma or administration of a dietary supplement were excluded.

RESULTS

A simple linear regression showed that for each gram of carbohydrates and total l fatty acids intake, the FEV₁/FVC ratio decreased -0.03 ml (β: -0.03, 95% CI -0.06 to -0.01, p = 0.008) and -0.009 ml (β: -0.00, 95% CI -0.02 to 0.00, p = 0.031) respectively. Pentadecanoic acid (C15:0) was associated with an increase of 0.47 ml in the FEV₁/FVC ratio for each milligram intake (β: 0.47, 95% CI 0.04 to 0.91, p = 0.031). Subsequently, when adjusted for calories intake, an increase of 0.53 ml was observed in the FEV₁/FVC for each milligram of C15:0 fatty acid intake (β:0.53, 95% CI 0.09 to 0.97, p = 0.018).

CONCLUSION

A positive association was observed between pentadecanoic acid and the FEV₁/FVC ratio with a beneficial effect on patients with COPD.

Favorable association of polyphenol-rich diets with lung function: Cross-sectional findings from the Moli-sani study

BACKGROUND

The association of the polyphenol content of human diet with pulmonary function is not yet fully understood. This study aims at evaluating the association of polyphenol consumption with lung function in a novel holistic approach.

METHODS

A cross-sectional analysis of 4551 women and 5108 men (age ≥35 years) from the Moli-sani study was performed. Participants were randomly recruited from the general population. The EPIC-FFQ was used for the dietary assessment. Polyphenol intakes were calculated using Eurofir-eBASIS, and a polyphenol antioxidant content (PAC) score was constructed to assess the total content of the diet in these nutrients. Pulmonary function maneuvers were performed, and the forced vital capacity (FVC) and forced expiratory volume in the first second (FEV₁) were measured; FVC% predicted and FEV₁% predicted were computed using the European Community of Coal and Steel prediction equations that included height and age.

RESULTS

In both genders, in age, height, and energy intake adjusted models, the majority of classes of polyphenols (mg/day) showed a positive association with FEV₁, FVC, FEV₁% predicted, and FVC% predicted (β-coef >0, P < .05). Associations remained significant after adjustment for confounding factors in most cases (β-coef >0, P < .05). The PAC score was associated in both genders with an increase in pulmonary function parameters (β-coef >0, P < .05). The inclusion of white blood cell (WBC) counts in the multivariate model reduced the association in men but not in women. .

CONCLUSIONS

A higher overall polyphenol content of human diet was associated with better pulmonary function in a general population. The association might be partially mediated by WBC in men.

The effect of dietary components on inflammatory lung diseases - a literature review

Anti-inflammatory treatment in chronic inflammatory lung diseases usually involves glucocorticosteroids. With patients suffering from serious side effects or becoming resistant, specific nutrients, that are suggested to positively influence disease progression, can be considered as new treatment options. The dietary inflammatory index is used to calculate effects of dietary components on inflammation and lung function to identify most potent dietary components, based on 162 articles. The positive effects of n-3 PUFAs and vitamin E on lung function can at least partially be explained by their anti-inflammatory effect. Many other dietary components showed only small or no effects on inflammation and/or lung function, although the number of weighted studies was often too small for a reliable assessment. Optimal beneficial dietary elements might reduce the required amounts of anti-inflammatory treatments, thereby decreasing both side effects and development of resistance as to improve quality of life of patients suffering from chronic inflammatory lung diseases.

Effects of a dietary intervention with conjugated linoleic acid on immunological and metabolic parameters in children and adolescents with allergic asthma--a placebo-controlled pilot trial

Background

Circumstantial evidence suggests that conjugated linoleic acid (CLA) beneficially modulates immune function in allergic subjects. C9,t11-CLA, naturally occurring in ruminant fats, is suggested to be the effective isomer. In contrast, for the t10,c12-CLA isomer, which is naturally found only in traces but usually constitutes a relevant part in commercial CLA mixtures, adverse effects have been reported. Aim of this study was to assess putative immunomodulatory effects of highly enriched c9,t11-CLA in allergic subjects. To our best knowledge, our study is the first in that a CLA preparation was used for such purpose which was free of t10,c12-CLA.

Design

Twenty-nine asthmatic children and adolescents (age 6–18 y) with diagnosed allergic sensitization against grass pollen, house dust mite, or cat hair/epithelia consumed daily a portion of yoghurt containing either 3 g CLA (75 % c9,t11-CLA, 87 % purity) or placebo (safflower oil) over a period of 12 weeks. At study start and end, lung function parameters, specific IgE, in vitro allergen-induced cytokine production in peripheral blood mononuclear cells (PBMC), plasma ECP, urinary 8-oxodG as marker of oxidation, fatty acid profiles of erythrocytes, and routine haematological parameters were determined. Prior to blood samplings, 3-days dietary records were requested. Throughout the study, the participants documented daily their peak expiratory flow and kept protocol about their allergy symptoms and usage of demand medication.

Results

In contrast to the CLA group, PBMC-produced IFN-γ and IL-4 increased significantly and by trend, respectively, in the placebo group. Moreover, plasma ECP tended to increase in the placebo group. In the pollen subgroup, FEV1 improved upon both CLA and placebo oil supplementation. In both intervention groups, the n-6/n-3 PUFA ratio in red blood cells decreased, mainly due to an increase in n-3 PUFA. Moreover, 8-oxodG excretion increased in both groups. No changes occurred regarding specific IgE concentrations, allergy symptoms, and volume parameters.

Conclusion

Our results indicate that CLA modestly dampens the inflammatory response on the cellular level. A clinically relevant amelioration of the symptoms could not be proved in atopic manifest patients.

Trial registration

NCT01026506.

Innate immunity is a key factor for the resolution of inflammation in asthma

The resolution of inflammation is an integral and natural part of the physiological response to tissue injury, infection and allergens or other noxious stimuli. Resolution is now recognised as an active process with highly regulated cellular and biochemical events. Recent discoveries have highlighted that innate inflammatory cells have bimodal effector functions during the inflammatory response, including active roles during the resolution process. Several mediators displaying potent pro-resolving actions have recently been uncovered. Lipoxin A4, the lead member of this new class of pro-resolving mediators, has anti-inflammatory actions on type 2 innate lymphoid cells and pro-resolving actions through natural killer cells in asthma immunobiology. Eosinophils are also able to control crucial aspects of resolution through the generation of pro-resolving mediators. Uncontrolled asthma has been associated with a defect in the generation of specialised pro-resolving mediators, including lipoxin A4 and protectin D1. Thus, bioactive stable analogue mimetics of these mediators that can harness endogenous resolution mechanisms for inflammation may offer new therapeutic strategies for asthma and airway inflammation associated diseases.

Natural history of COPD: Focusing on change in FEV1

The natural history of chronic obstructive pulmonary disease (COPD) is usually described with a focus on change in forced expiratory volume in 1 s (FEV1 ) over time as this allows for exploration of risk factors for an accelerated decline-and thus of developing COPD. From epidemiological studies we have recognized important risk factors such as smoking, exposure to biomass and occupational exposures, but we have also learnt about features such as chronic bronchitis, airway hyper-responsiveness and asthma that seem to accelerate decline in FEV1 independent of exposures. In addition we are gradually beginning to better link early life events to subsequent risk of disease in adulthood. Although more complicated, our current understanding of COPD has come a long way from being a simple image of smoking leading to poor lungs.

Fish intake and risk of chronic obstructive pulmonary disease in 2 large US cohorts

BACKGROUND

Despite mechanistic data that linked fish and omega-3 (n-3) PUFAs with lower risk of chronic obstructive pulmonary disease (COPD), epidemiologic data remain scarce. Fish and n-3 PUFAs are an important component of the prudent dietary pattern that is thought to be protective in the onset of COPD.

OBJECTIVE

We examined the role of fish and PUFA intakes on risk of developing COPD while taking into account the overall dietary pattern.

DESIGN

We investigated the objective in 120,175 women and men from the Nurses' Health Study and Health Professionals Follow-Up Study. Over the study period (1984-2000), there were 889 cases of newly diagnosed COPD. Cumulative average intakes of fish, eicosapentaenoic acid, docosahexaenoic acid, n-3 PUFAs, n-6 PUFAs, and the n-3:n-6 ratio were calculated from repeated food-frequency questionnaires. Because fish is a food group included in the prudent pattern, we derived a new prudent pattern without the contribution from fish, and we termed this pattern the "modified prudent" pattern. We performed multivariable Cox proportional hazards models.

RESULTS

Before the dietary pattern was taken into account, and with 14 factors controlled for, we showed that more-frequent fish intake (≥4 servings/wk) was inversely associated with risk of COPD [adjusted pooled HR for the highest intake compared with the lowest intake (<1 serving/wk): 0.71; 95% CI: 0.54, 0.94]. After additional adjustment for the dietary pattern (modified prudent and Western patterns), the association was NS (0.84; 95% CI: 0.63, 1.13). No significant associations were shown between PUFA intakes and risk of COPD.

CONCLUSION

Although COPD-prevention efforts should continue to focus on smoking cessation, these prospective findings support the importance of promoting a healthy diet in multi-interventional programs to prevent COPD instead of focusing on changes in an isolated food or nutrient.

Dietary and supplemental antioxidant and anti-inflammatory nutrient intakes and pulmonary function

OBJECTIVE

A limited but growing body of evidence supports a significant role of antioxidant and anti-inflammatory micronutrients in pulmonary health. We investigated the associations of dietary and supplemental intakes of vitamins A, C, E and D, Se and n-3 PUFA with pulmonary function in a population-based study.

DESIGN

Population-based, cross-sectional study and data analysis of fruits and vegetables, dairy products and fish, vitamins A, C, E and D, Se and n-3 PUFA supplemental intakes, pulmonary risk factors and spirometry.

SUBJECTS

Chinese older adults (n 2478) aged 55 years and above in the Singapore Longitudinal Ageing Studies.

RESULTS

In multiple regression models that controlled simultaneously for gender, age, height, smoking, occupational exposure and history of asthma/chronic obstructive pulmonary disease, BMI, physical activity, and in the presence of other nutrient variables, daily supplementary vitamins A/C/E (b = 0·044, SE = 0·022, P = 0·04), dietary fish intake at least thrice weekly (b = 0·058, SE = 0·016, P < 0·0001) and daily supplementary n-3 PUFA (b = 0·068, SE = 0·032, P = 0·034) were individually associated with forced expiratory volume in the first second. Supplemental n-3 PUFA was also positively associated with forced vital capacity (b = 0·091, SE = 0·045, P = 0·045). No significant association with daily dairy product intake, vitamin D or Se supplements was observed.

CONCLUSIONS

The findings support the roles of antioxidant vitamins and n-3 PUFA in the pulmonary health of older persons.

The Association Between Dietary Intake and Phenotypical Characteristics of COPD in the ECLIPSE Cohort

Background: Diet is a potentially modifiable risk factor in the development and progression of many diseases, and there is evidence that diet plays a role in COPD. Objective: Evaluate the relationship between dietary intake and clinical characteristics of COPD in a large and well-characterized population of COPD patients and controls who were part of the ECLIPSE study. Methods: Limited diet records were available from 2,167 participants at 8 time points over a 3-year period. Participants reported the amount they had consumed over the last 24 hours for 8 food categories. Intake of each food group was handled as a dichotomous variable (Yes/last 24 hours at any of the 8 follow-up points vs. No at all 8 points). These 2 groups were then compared using clinical outcome measures at the last available follow-up that included lung function, emphysema, 6-minute walk, St. George's Respiratory Questionaire (SGRQ) scores, the change in these scores over a 3-year period, and inflammatory biomarkers. Multivariate models for each food group and each outcome measure were run to adjust for confounding factors of age, sex, body mass index (BMI), and smoking. Results: Participants who demonstrated recent consumption of foods associated with a healthful diet, including fish, fruit, tea, and dairy products, had greater lung function measures and less decline over time, less emphysema and emphysema progression, greater 6-minute walk and SGRQ scores, and lower levels of certain inflammatory markers. Increasing the number of diet record time points that were included in the analysis improved ability to detect significant associations. Conclusion: Diet as a possible modifiable risk factor in COPD continues to warrant investigation.

Obesity and asthma: physiological perspective

Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC). Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma.

Lipoxins, resolvins and protectins: new leads for the treatment of asthma

BACKGROUND

The pathobiology of asthma is characterized by the production of pro-inflammatory eicosanoids that play important roles in regulating airway responses. Recognition of the biosynthetic pathways and sites of action for 5-lipoxygenase-derived leukotrienes has led to the successful development of two different classes of asthma therapeutics.

OBJECTIVES

In this review, we describe structurally distinct lipid mediators derived from arachidonic acid and ω-3 fatty acids that have anti-inflammatory and pro-resolving actions. These counter-regulatory lipid mediators are generated in the airway during asthma and defects in their production are associated with disease severity.

CONCLUSION

These natural small molecules are rapidly inactivated, but serve as rationale templates for the design of stable analogues with protective actions that could serve as new therapeutic leads for asthma.

Curcumins-rich curry diet and pulmonary function in Asian older adults

Background

Research on the effects of dietary nutrients on respiratory health in human populations have not investigated curcumin, a potent anti-oxidant and anti-inflammatory compound present principally in turmeric used in large amounts in Asian curry meals.

Objectives

To examine the association of curry intake with pulmonary function among smokers and non-smokers.

Design

The frequency of curry intake, respiratory risk factors and spirometry were measured in a population-based study of 2,478 Chinese older adults aged 55 and above in the Singapore Longitudinal Ageing Studies.

Results

Curry intake (at least once monthly) was significantly associated with better FEV₁ (b = 0.045±0.018, p = 0.011) and FEV₁/FVC (b = 1.14±0.52, p = 0.029) in multivariate analyses that controlled simultaneously for gender, age, height, height-squared, smoking, occupational exposure and asthma/COPD history and other dietary or supplementary intakes. Increasing levels of curry intake (‘never or rarely’, ‘occasional’, ‘often’, ‘very often’) were associated with higher mean adjusted FEV₁ (p for linear trend = 0.001) and FEV₁/FVC% (p for linear trend = 0.048). Significant effect modifications were observed for FEV₁ (curry* smoking interaction, p = 0.028) and FEV₁/FVC% (curry*smoking interaction, p = 0.05). There were significantly larger differences in FEV₁ and FEV₁/FVC% between curry intake and non-curry intake especially among current and past smokers. The mean adjusted FEV₁ associated with curry intake was 9.2% higher among current smokers, 10.3% higher among past smokers, and 1.5% higher among non-smokers.

Conclusion

The possible role of curcumins in protecting the pulmonary function of smokers should be investigated in further clinical studies.

Resolution of inflammation in asthma

The resolution of inflammation in healthy airways is an active process, with specialized mediators and cellular mechanisms enlisted to restore tissue homeostasis. This article focuses on recent discoveries of natural mediators derived from essential fatty acids, including ω-3 fatty acids, with anti-inflammatory and pro-resolving. These pro-resolving mediators serve as agonists at specific receptors. Asthma is an incurable disease of chronic, nonresolving inflammation of the airways. While the biosynthesis of pro-resolving mediators occurs during asthma, defects in their production are associated with disease severity, suggesting that the pathobiology of asthma may result in part from impaired resolution of airway inflammation.

Resolvin D1 and aspirin-triggered resolvin D1 promote resolution of allergic airways responses

Asthma is a disease of airway inflammation that in most cases fails to resolve. The resolution of inflammation is an active process governed by specific chemical mediators, including D-series resolvins. In this study, we determined the impact of resolvin D1 (RvD1) and aspirin-triggered RvD1 (AT-RvD1) on the development of allergic airway responses and their resolution. Mice were allergen sensitized, and RvD1, AT-RvD1 (1, 10, or 100 ng), or vehicle was administered at select intervals before or after aerosol allergen challenge. RvD1 markedly decreased airway eosinophilia and mucus metaplasia, in part by decreasing IL-5 and IκBα degradation. For the resolution of established allergic airway responses, AT-RvD1 was even more efficacious than RvD1, leading to a marked decrease in the resolution interval for lung eosinophilia, decrements in select inflammatory peptide and lipid mediators, and more rapid resolution of airway hyperreactivity to methacholine. Relative to RvD1, AT-RvD1 resisted metabolic inactivation by macrophages, and AT-RvD1 significantly enhanced macrophage phagocytosis of IgG-OVA-coated beads in vitro and in vivo, a new proresolving mechanism for the clearance of allergen from the airways. In conclusion, RvD1 and AT-RvD1 can serve as important modulators of allergic airway responses by decreasing eosinophils and proinflammatory mediators and promoting macrophage clearance of allergen. Together, these findings identify D-series resolvins as potential proresolving therapeutic agents for allergic responses.

Total dietary antioxidant capacity and lung function in an Italian population: a favorable role in premenopausal/never smoker women

BACKGROUND/OBJECTIVES

Antioxidant-rich foods may favorably influence lung function. We examined possible associations between the total dietary antioxidant capacity (TAC) and pulmonary function in a healthy Italian population.

SUBJECTS/METHODS

Until May 2009, 22,300 persons were randomly recruited from the general population in the Moli-sani project. A sample only including healthy women (5824) and men (5848) was analyzed. TAC was measured in foods by three different assays and the ferric reducing-antioxidant power (FRAP) assay was selected as the better indicator of dietary TAC. The European Investigation into Cancer and Nutrition Food Frequency Questionnaire was used for dietary assessment. The association between quintiles of dietary FRAP and pulmonary indexes was assessed using analysis of variance separately for men and women.

RESULTS

After adjustment for confounders, women in the highest quintile of FRAP intake had +39 ml forced expiratory volume in the first second (FEV(1)) and +54 ml forced vital capacity, compared with those in the lowest quintile (P for trend ≤0.006). Stratified analysis showed that this relationship only occurred in women who were premenopausal/never smokers. In this subgroup, the observed effect of higher FRAP intake on FEV(1) was equivalent to an improvement in pulmonary age of 3.3 years. In men, all significant associations between pulmonary function and TAC were lost after adjustment for confounding.

CONCLUSIONS

Dietary TAC may have a favorable role in respiratory health, particularly in premenopausal/never smoker women.

Fat-1 transgenic mice with elevated omega-3 fatty acids are protected from allergic airway responses

Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been implicated in the alleviation of asthma. Recent studies have demonstrated that the n-3 PUFA derived lipid mediators, protectin D1 and resolvin E1, may act as potent resolution agonists in airway inflammation. The effects of the n-3 PUFA tissue status itself on asthma pathogenesis remains to be further investigated. In this study allergic airway inflammation induced by allergen sensitization and aerosol challenge in Fat-1 and wild-type mice was investigated. Fat-1 transgenic mice displayed increased endogenous lung n-3 PUFA. When allergen-sensitized and aerosol-challenged, these animals had decreased airway inflammation with decreased leukocyte accumulation in bronchoalveolar lavage fluid and lung parenchyma. The Fat-1 mice had a shift to the right in the dose-response relationship for methacholine induced bronchoconstriction with a significant increase in the log ED200. The Fat-1 mice had lower BALF concentrations of the pro-inflammatory cytokines IL-1α, IL-2, IL-5, IL-9, IL-13, G-CSF, KC and RANTES. Furthermore, increased lung tissue amounts of the counter-regulatory mediators protectin D1 and resolvin E1 were found in Fat-1 mice after bronchoprovocative challenge. These results therefore demonstrate a direct protective role for lung n-3 PUFA in allergic airway responses and an increased generation of protectin D1 and resolvin E1 in this context.

Lifestyle and the Respiratory Health of Children

This article offers a review of the potential influences of personal lifestyle on respiratory health in children, looking at both healthy individuals and those with respiratory disorders. As with many aspects of health, regular physical activity, an appropriate diet, and avoidance of obesity and cigarette smoke all contribute to optimal development of the healthy child. An active lifestyle is associated with greater static and dynamic lung volumes, greater efficiency of the ventilatory process, and an optimization of breathing patterns. The risk of upper respiratory infections is also reduced in those maintaining a moderate level of physical activity. Maternal smoking during pregnancy, as well as active and passive smoking, all have an adverse influence on lung function in the child, the largest effects being on dynamic lung volumes. The risk of developing asthma seems reduced in children who maintain a normal body mass and are physically active. A program of graded physical activity is of therapeutic value in a number of established respiratory conditions, including asthma, cystic fibrosis, and ventilatory impairment from neuromuscular disorders. Exercise carries a slight risk of fatalities from asthma and anaphylactic reactions. In designing an optimal physical activity program, it is also important to guard against the hazards of deep oronasal breathing, including the precipitation of bronchospasm by the inhalation of cold, dry air and pollens; an increased exposure to atmospheric pollutants (reducing and oxidant smog, fine and ultra-fine particulates, and carbon monoxide); and possible long-term dangers from chlorine derivatives in the atmosphere of indoor swimming pools.

The influence of traffic-related pollution on individuals' life-style: results from the BRFSS

This paper employs the Behavioral Risk Factor Surveillance System (2001) data in conjunction with the Environmental Protection Agency's Air Quality System data to investigate how air pollution caused by motor vehicle emissions affects the likelihood of good health and the amount of health investments. Models are estimated using three different measures of overall health: a measure of self-assessed health and two health outcome indicators (asthma and blood pressure). A multivariate probit approach is used to estimate recursive systems of equations for self-assessed health, health outcomes and life-styles. The most interesting result concerns the influence of pollution on health-improving life-style choices: only if traffic pollution is in the 'satisfactory range' (AQI level at or below 100), individuals will have incentive to invest in health.

Interleukin-17 regulation: an attractive therapeutic approach for asthma

Interleukin (IL)-17 is recognized to play a critical role in numerous immune and inflammatory responses by regulating the expression of various inflammatory mediators, which include cytokines, chemokines, and adhesion molecules. There is growing evidence that IL-17 is involved in the pathogenesis of asthma. IL-17 orchestrates the neutrophilic influx into the airways and also enhances T-helper 2 (Th2) cell-mediated eosinophilic airway inflammation in asthma. Recent studies have demonstrated that not only inhibitor of IL-17 per se but also diverse regulators of IL-17 expression reduce antigen-induced airway inflammation, bronchial hyperresponsiveness, and Th2 cytokine levels in animal models of asthma. This review will summarize the role of IL-17 in the context of allergic airway inflammation and discuss the therapeutic potential of various strategies targeting IL-17 for asthma.

Assessment of dietary fat intake and innate immune activation as risk factors for impaired lung function

BACKGROUND/OBJECTIVES

Preservation of lung health with aging is an important health issue in the general population, as loss of lung function with aging can lead to the development of obstructive lung disease and is a predictor of all-cause and cardiovascular mortality. Inflammation is increasingly linked to loss of lung function and evidence suggests that consumption of dietary fat exacerbates inflammation. We aimed to determine the association between dietary fat intake and lung function in older people.

SUBJECTS/METHODS

Participants from the Hunter community study, a population-based cohort, were recruited during 2004 and 2005. Participants received a clinical assessment, including spirometry, and provided a blood sample. Diets were analyzed using food-frequency questionnaires. Plasma interleukin (IL)-6 and C-reactive protein was measured by Enzyme-Linked immunosorbent assay.

RESULTS

Using backward stepwise linear regression, %energy from dietary fat, age and plasma IL-6 were considered as negative predictors of forced expiratory volume in one second (FEV(1)) in men. Also in men, % energy intake from dietary fat, age, body mass index and IL-6 were negative predictors of %predicted forced vital capacity (FVC). Smoking and age were negative predictors of FEV(1)/FVC. In women, plasma IL-6 and age were negative predictors of %FVC, whereas obesity was positively associated with FEV(1)/FVC.

CONCLUSIONS

An increased proportion of fat in the diet is associated with the reduced lung function in older men. Dietary-fat induced innate immune activation and IL-6 release may contribute to this effect. Dietary interventions involving fat restriction should be further investigated as means of preserving lung function with aging.

Uncontrolled airway inflammation in lung disease represents a defect in counter-regulatory signaling

Counter-regulatory lipid mediators are generated during airway inflammation to promote resolution. Defects in the production of these lipid mediators have now been associated with several diseases of persistent airway inflammation. Lipoxins are the lead members of this class of anti-inflammatory and proresolving chemical mediators. Recently, several new families of fatty acid-derived counter-regulatory mediators have been discovered, including the resolvins and protectins. Diminished formation of these endogenous protective signals would interrupt the natural resolution of inflammation. Here, we review how rapidly emerging information on lipoxins, resolvins and protectins is providing new insights into the pathophysiology of chronic airway inflammation in several common illnesses, including asthma.

Dietary factors and the development of asthma

Asthma and allergies continue to be major public health problems in affluent westernized countries. Changes in dietary habits dating from before the increase in asthma prevalence may have a role in the development of asthma and allergies. Many studies have investigated the role of specific nutrients in asthma and allergies, and intervention studies with supplementation of particular nutrients have been conducted, but results have been mixed. It is likely that nutrients may exert their strongest effect early in life, when both the immune system and the lungs are not yet fully developed.

Resolvin E1 regulates interleukin 23, interferon-gamma and lipoxin A4 to promote the resolution of allergic airway inflammation

Interleukin 23 (IL-23) is integral to the pathogenesis of chronic inflammation. The resolution of acute inflammation is an active process mediated by specific signals and mediators such as resolvin E1 (RvE1). Here we provide evidence that RvE1, in nanogram quantities, promoted the resolution of inflammatory airway responses in part by directly suppressing the production of IL-23 and IL-6 in the lung. Also contributing to the pro-resolution effects of RvE1 treatment were higher concentrations of interferon-gamma in the lungs of RvE1-treated mice. Our findings indicate a pivotal function for IL-23 and IL-6, which promote the survival and differentiation of IL-17-producing T helper cells, in maintaining inflammation and also identify an RvE1-initiated resolution program for allergic airway responses.

Dietary fiber, lung function, and chronic obstructive pulmonary disease in the atherosclerosis risk in communities study

Recent data suggest beneficial effects of fiber intake on chronic respiratory symptoms in adults that are independent of antioxidant vitamin intake, but little is known about fiber consumption in relation to lung function and chronic obstructive pulmonary disease (COPD). The authors investigated the association of fiber intake with lung function and COPD in 11,897 US men and women from the Atherosclerosis Risk in Communities study (1987-1989). After control for potential confounders, positive associations were found between lung function and fiber intake from all sources as well as from cereal or fruit alone. Compared with those in the lowest quintile, participants in the highest quintile of total fiber intake had a 60.2-ml higher forced expiratory volume in 1 second (FEV(1)) (p for trend < 0.001), 55.2-ml higher forced vital capacity (FVC) (p = 0.001), 0.4% higher FEV(1)/FVC ratio (p = 0.040), 1.8% higher percent predicted FEV(1) (p < 0.001), and 1.4% higher percent predicted FVC (p = 0.001). Adjusted odds ratios of COPD for the highest versus lowest quintiles of intake were 0.85 (p = 0.044) for total fiber, 0.83 (p = 0.021) for cereal fiber, and 0.72 (p = 0.005) for fruit fiber. This study provides the first known evidence that dietary fiber is independently associated with better lung function and reduced prevalence of COPD.

The relation between dietary intake of individual fatty acids, FEV1 and respiratory disease in Dutch adults

BACKGROUND

A reduced dietary intake of n-3 fatty acids, in association with increased n-6 fatty acid intake, has been proposed as a potential aetiological factor for chronic obstructive pulmonary disease (COPD) and asthma. However, the relative importance of individual fatty acids within the n-3 and n-6 categories on this effect has not been widely investigated. We have studied the relation between individual fatty acid intakes, lung function and self-reported respiratory symptoms and diagnoses in a representative sample of more than 13,000 Dutch adults.

METHODS

Intake of individual fatty acids was estimated by a food frequency questionnaire and analysed in relation to measures of forced expiratory volume in 1 s (FEV1) and to questionnaire reported wheeze, asthma and COPD symptoms.

RESULTS

After adjusting for confounding, we found no protective association between individual n-3 fatty acid intakes and FEV1. Higher intakes of some n-6 fatty acids were associated with lower FEV1, this effect being most marked for c22:4 n-6 docosatetraenoic acid (reduction in FEV1 between the highest and lowest quintile of intake 54.5 ml (95% CI -81.6 to -27.4)). Most of the n-6 fatty acid effects interacted significantly with smoking, their effects being strongest in current smokers. Individual n-3 fatty acid intakes were generally associated with a higher risk of wheeze in the past year, but otherwise there was little or no association between fatty acid intake and wheeze, doctor diagnosed asthma or other respiratory symptoms.

CONCLUSIONS

A high intake of n-3 fatty acids does not appear to protect against COPD or asthma, but a high intake of several n-6 fatty acids is associated with a significant reduction in FEV1, particularly in smokers. These findings indicate that high dietary intake of n-6 fatty acids, rather than reduced n-3 intake, may have an adverse effect on lung health.

Association of fatty acids in serum phospholipids with lung function and bronchial hyperresponsiveness in adults

BACKGROUND

The dietary intake of certain fatty acids might have an impact on inflammatory processes in the lung and therefore contribute to the development of lung diseases like asthma or COPD.

METHODS

In this study data from a population based cross-sectional study on respiratory health including measurement of fatty acids in serum phospholipids of 593 adults between 20 and 64 years of age were analyzed.

RESULTS

Statistically significant positive associations were found between percentage predicted FEV1 (P = 0.0085) and FVC (P = 0.0267) and docosahexaenoic acid concentration in serum phospholipids in men. Dihomo-gamma-linolenic acid content in serum phospholipids was significantly negatively associated with percentage predicted FEV1 (P = 0.0003) and FVC (P = 0.0045) and transformed dose-response slopes (P = 0.0488) in men. Palmitoleic acid was negatively associated with percentage predicted FEV1 (P = 0.0037) and FVC (P = 0.0029) in men. Other fatty acids in serum phospholipids did not consistently affect lung function parameters or bronchial hyperreactivity.

CONCLUSION

A high concentration of docosahexaenoic acid in serum phospholipids may have a protective effect on lung function. Because this long-chain n-3 polyunsaturated fatty acid is almost exclusively derived from marine oils, fish might have a beneficial effect on lung diseases.

The association of diet with respiratory symptoms and asthma in schoolchildren in Taipei, Taiwan

This study aimed to evaluate the association of diet with respiratory symptoms and asthma in schoolchildren in Taipei, Taiwan. An in-class interview survey elicited experiences of asthma and respiratory symptoms and consumption frequencies of the major food categories in 2290 fifth graders. Respiratory symptoms surveyed included persistent cough, chest tightness, wheezing with cold, wheezing without cold, dyspnea-associated wheezing, and exercise-induced cough or wheezing. Results showed that the consumption of sweetened beverages had the strongest association with respiratory symptoms and was positively associated with six of the seven respiratory symptoms (all p < 0.05). The adjusted odds ratios (aOR) ranged from 1.05 (95% confidence interval (CI = 1.01-1.09) for exercise-induced cough to 1.09 (95% CI = 1.03-1.16) for wheezing without cold. Egg consumption was associated with 5 of the 7 respiratory symptoms. Consumptions of seafood, soy products, and fruits were each negatively associated with one of the seven respiratory symptoms (all p < 0.05). Consumption of seafood was negatively associated with physician-diagnosed asthma and consumptions of sweetened beverages and eggs were positively associated with suspected asthma (p < 0.05). In conclusion, the study suggests that diet is associated with the respiratory symptoms in schoolchildren in Taipei. Consumptions of sweetened beverages and eggs are associated with increased risk of respiratory symptoms and asthma whereas consumptions of soy products and fruits are associated with reduced risk of respiratory symptoms.

Relationship of fish and cod oil intake with adult asthma

BACKGROUND

A diet rich in fish or cod oil might possibly reduce the risk for asthma and atopic diseases. However, previous studies show conflicting results and no studies have assessed the potential long-term effects of childhood fish intake on adult asthma.

OBJECTIVE

To investigate whether childhood and adult fish and cod oil intake was related to adult asthma.

METHODS

In a large population-based study, Respiratory Health in Northern Europe (RHINE), 16 187 subjects aged 23-54 years answered a postal questionnaire. The relations of fish and cod oil intake with asthma symptoms and asthma were analysed using multiple logistic and Cox regression analyses, with adjustment for gender, adult hayfever, smoking, age, body mass index, household size, dwelling, parental education and centre, and for maternal smoking and family history of hayfever and asthma in a subsample (n=2459).

RESULTS

Subjects from Iceland and Norway reported much more frequent intake of fish both in childhood and adulthood as compared with subjects from Sweden, Estonia and Denmark. Current fish intake less than weekly in adults was associated with more asthma symptoms, while more frequent fish intake did not appear to decrease the risk further. No dose-response association was found between childhood fish intake and adult asthma, but those who never ate fish in childhood had an increased risk for asthma and earlier asthma onset. Adult consumption of cod oil had a u-shaped association with asthma, with the highest risks in those taking cod oil never and daily.

CONCLUSION

A minimum level of weekly fish intake in adulthood was associated with protection against asthma symptoms in this large North-European multi-centre study. Subjects who never ate fish in childhood were at an increased risk for asthma. Both indicate a possible threshold effect of fish on asthma.

Vulnerability to air pollution health effects

INTRODUCTION

Ambient air pollution can have adverse effects on the health of exposed populations, but individuals or groups are not equally vulnerable, and pollution reduction benefits are likely to be unevenly distributed within a population. While the use of total-population risks is a valid approach for public health protection, it is increasingly recognized that more attention on vulnerable groups is necessary. This paper describes population vulnerability to the health effects of air pollutants using risk analysis concepts and based on available evidence.

METHODS

Publications reporting air pollution health risks for specific sub-populations, or more conceptual discussions of vulnerability, were selected following a literature search of the PubMed database. Only studies in the context of developed countries were included. Information on population characteristics and factors that can influence risk was assessed from the perspective of the vulnerability framework, and was used to outline interactions with biological susceptibility, exposure, and social coping.

RESULTS

Population characteristics encompass several factors that interact and confer vulnerability. Age, for example, regarded as significant mostly in terms of physiology, also relates to exposure through behaviours and activities that can be more amenable to prevention. Children are recognized as a high-risk group but their vulnerability may differ by childhood stage, while pregnant women are not explicitly identified as a vulnerable group despite growing evidence for reproductive risks. Social-economic factors have received little attention, although they can affect coping capacity as well as interact with susceptibility and exposure to air pollution.

CONCLUSIONS

Evidence for vulnerability components often lies in different fields of study and has not been evaluated in an integrated manner. Better understanding of population vulnerability can improve the scientific basis to assess risks and develop policies or other health protection initiatives to reduce the impacts of air pollution.

Associations between antioxidant status, markers of oxidative stress and immune responses in allergic adults

BACKGROUND

There has been growing interest in the role of antioxidant function in controlling inflammatory disease states, such as allergy. This study investigated the relationship between antioxidant status, markers of airways inflammation [exhaled nitric oxide (eNO)], oxidative stress (F(2) isoprostanes) and immune responses in allergic adults.

METHODS

Antioxidants (vitamins C, E, beta-carotene and selenium) and total antioxidant capacity (tAC) in serum were examined in relation to eNO, plasma F(2) isoprostanes and peripheral blood mononuclear cell (PBMC) cytokine and lymphoproliferative response to house dust mite (HDM) allergen, Staphylococcus enterotoxin B (SEB), phytohaemaglutinin (PHA) and lipopolysaccharide (LPS) in 54 allergic adults.

RESULTS

Firstly, levels of specific vitamins did not correlate with tAC. Secondly, we did not see any evidence that specific vitamin levels (or tAC) were associated with either polarization or attenuation of in vitro immune responses. If anything, there were positive correlations between antioxidant (vitamin C and selenium) levels and HDM allergen responses [lymphoproliferation (selenium; r=0.35, P=0.013) and both Th2 IL13 (vitamin C; tau=0.254, P=0.028) and Th1 IFN-gamma (vitamin C; tau=0.302, P=0.009) responses]. There were also significant positive relationships between antioxidant levels and IL-10 responses to polyclonal stimulation by SEB (r=0.292, P=0.036) and LPS (r=0.34, P=0.015) (beta-carotene) and PHA (r=0.34, P=0.021) (tAC). Thirdly, although airways inflammation (eNO) was associated with both in vitro and in vivo (skin test reactivity) to HDM, we did not see any correlation between eNO and oxidative stress (F(2)-isoprostanes). Finally, there were no consistent relationships between oxidative stress and immune responses.

CONCLUSION

There was no evidence that higher antioxidant levels were associated with reduced allergen responsiveness in allergic adults. If anything, antioxidant status was associated with increased immune responsiveness. The significance of this needs to be addressed in future intervention studies.

Protectin D1 is generated in asthma and dampens airway inflammation and hyperresponsiveness

Protectins are newly identified natural chemical mediators that counter leukocyte activation to promote resolution of inflammation. In this study, we provide the first evidence for protectin D1 (PD1, 10R,17S-dihydroxy-docosa-4Z,7Z,11E,13E,15Z,19Z-hexaenoic acid) formation from docosahexaenoic acid in human asthma in vivo and PD1 counterregulatory actions in allergic airway inflammation. PD1 and 17S-hydroxy-docosahexaenoic acid were present in exhaled breath condensates from healthy subjects. Of interest, levels of PD1 were significantly lower in exhaled breath condensates from subjects with asthma exacerbations. PD1 was also present in extracts of murine lungs from both control animals and those sensitized and aerosol challenged with allergen. When PD1 was administered before aeroallergen challenge, airway eosinophil and T lymphocyte recruitment were decreased, as were airway mucus, levels of specific proinflammatory mediators, including IL-13, cysteinyl leukotrienes, and PGD(2), and airway hyperresponsiveness to inhaled methacholine. Of interest, PD1 treatment after aeroallergen challenge markedly accelerated the resolution of airway inflammation. Together, these findings provide evidence for endogenous PD1 as a pivotal counterregulatory signal in allergic airway inflammation and point to new therapeutic strategies for modulating inflammation in asthmatic lung.

Current clinical applications of omega-6 and omega-3 fatty acids

BACKGROUND

Recent years have brought a resurgence of research interest in fatty acids, with studied fields running the gamut of human disease. This movement has run in parallel with an increased interest in using nutrition modalities as therapeutic measures, as opposed to their conventional role as energy sources. The aim of this manuscript is to provide a basic review of current clinical applications of omega-6 and omega-3 fatty acids, with a particular focus on the latter.

METHODS

A selective review of the voluminous literature, including randomized controlled trials, meta-analyses, population studies, and case reports, was used to compile data and identify trends in pertinent clinical applications of fatty acid therapy.

CONCLUSIONS

There are a myriad of disorders and maladies that seem to benefit from fatty acid supplementation, specifically omega-3 fatty acids. It has clearly been shown that omega-3 fatty acid supplementation provides a protective benefit in heart disease, and in particular sudden cardiac death. Rheumatoid arthritis (RA) is another disease entity that has been proven to benefit from this nutrition intervention, with improvement in symptoms and diminished nonsteroidal antiinflammatory drug (NSAID) usage. In addition, many psychiatric disorders, particularly schizophrenia and major depressive disorder (MDD), have shown positive results when supplementation has been used as an adjunct to standard pharmacotherapy. The remainder of clinical applications for omega-3 fatty acids requires further investigation. Specifically, according to preliminary clinical evidence, parenteral administration of fatty acids warrants further study.

Fatty acids in serum cholesteryl esters in relation to asthma and lung function in children

BACKGROUND

Dietary fatty acid intake has been proposed to contribute to asthma development with n-6 polyunsaturated fatty acids (PUFA) having a detrimental and n-3 PUFA a protective effect.

OBJECTIVE

The aim of our analysis was to explore the relationship between fatty acid composition of serum cholesteryl esters as marker of dietary intake and prevalence of asthma, impaired lung function and bronchial hyper-responsiveness in children.

METHODS

The study population consisted of 242 girls and 284 boys aged 8-11 years, living in Munich, Germany. Data were collected by parental questionnaire, lung function measurement and skin prick test according to the International Study of Asthma and Allergies in Childhood phase II protocol. Confounder-adjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated for the association between quartiles of fatty acid concentration and health outcomes with the first quartile as reference.

RESULTS

n-3 PUFA: levels of eicosapentaenoic acid were not related to asthma and impaired lung function. Linolenic acid levels were positively associated with current asthma (OR for fourth quartile 3.35, 95% CI 1.29-8.66). Forced expiratory volume in 1 s (FEV(1)) values decreased with increasing levels of linolenic acid (p for trend=0.057). n-6 PUFA: there was a strong positive association between arachidonic acid levels and current asthma (OR(4th quartile) 4.54, 1.77-11.62) and a negative association with FEV(1) (P=0.036). In contrast, linoleic acid was negatively related to current asthma (OR(4th quartile) 0.34, 0.14-0.87) and FEV(1) values increased with increasing levels of linoleic acid (P=0.022). The ratio of measured n-6 to n-3 PUFA as well as levels of palmitic and oleic acid were not consistently related to asthma or lung function.

CONCLUSION

Our data do not support the hypothesis of a protective role of n-3 PUFA. Elevated arachidonic acid levels in children with asthma may be because of a disturbed balance in the metabolism of n-6 PUFA or may be secondary to inflammation in these patients.