Nutrition and allergic disease

Dairy intake in association with asthma symptoms among a large sample of children and adolescents: a cross-sectional study

Background and objective

Dairy products may be associated with an increased risk of asthma, although there is little scientific evidence to support this association. The goal of this study was to explore the association between dairy consumption and asthma symptoms.

Materials and methods

This cross-sectional study was conducted on children and adolescents aged 6-8 and 13-14 years living in central Iran. Dietary food consumption was assessed using a multiple-choice questionnaire. Logistic regression was used to obtain odds ratios for the association between milk, other dairy products, and total dairy consumption with the risk of asthma symptoms.

Results

In total, 7,667 participants (3,414 boys and 4,253 girls) were included in the current study. Milk intake and total dairy consumption were not associated with the likelihood of wheezing, asthma confirmed by a doctor, current asthma, and asthma medication use. In addition, there was no association between other dairy product intake and the odds of wheezing in the past 12 months in the crude model. However, after adjusting for several confounders, those in the top category had lower odds of wheezing in the past 12 months than those in the bottom category (OR: 0.58; 95% CI: 0.40-0.85).

Conclusion

The consumption of dairy products other than milk, including cheese and yogurt, might reduce the likelihood of wheezing in children and adolescents.

The Association between Dietary Intake, Asthma, and PCOS in Women from the Australian Longitudinal Study on Women's Health

Dietary intake potentially modifies the prevalence or severity of asthma. The prevalence of asthma is higher in women with polycystic ovary syndrome (PCOS); it is not known if diet confounds or modifies the association between asthma and PCOS. The aims of this study were: (i) To determine if the association of PCOS and asthma is independent of dietary pattern and (ii) to determine if dietary pattern modifies the association between PCOS and asthma. Women in this study were from the Australian Longitudinal Study on Women's Health (ALSWH) cohort born between 1973 to 1978 and aged 18 to 23 years (n = 7382). Logistic regression was used to assess the association between PCOS and asthma, adjusting for the following: (i) Potential confounders identified a priori and (ii) dietary patterns (z-score) identified by principle component analysis. In the adjusted analysis, women with PCOS were more likely to have asthma than the women without PCOS (OR 1.35 and 95% CI, 1.02 and 1.78). This relationship was not altered by further adjustment for dietary patterns (non-core food, meats and takeaway, or Mediterranean-style pattern). In the interaction analysis, only the women consuming less than the median intake of non-core foods (i.e., lower intake of discretionary or unhealthy foods) and with PCOS were more likely to have asthma (OR 1.91 and 95% CI, 1.29 and 2.82). Dietary intake did not confound the relationship between PCOS and asthma. Other mechanistic pathways are likely responsible for the asthma and PCOS association, and further studies assessing factors such as oral contraceptive use and sex steroid hormones warrant investigation.

Nutritional disorders resulting from food allergy in children

The elimination of food allergens that contribute essential nutrients in paediatrics may lead to the development of nutritional disorders. The most common nutritional disorders include poor growth, micronutrient deficiencies and feeding difficulties. Of the aforementioned, growth faltering has been well studied and is seen as a common presenting factor in paediatric food allergy. However, the use of different criteria and cut-off values makes it difficult to establish the overall effect. The impact of number and type of foods eliminated and comorbidities has yielded varying results, although there seems to be a trend towards worsening growth with atopic dermatitis and the avoidance of cow's milk. Low micronutrient intake is common in paediatric food allergy; however, a low intake does not necessarily translate into a deficiency as measured by biomarkers. Vitamin D and calcium have been well studied, and a long-lasting impact on bone mineral density has been found. However, other micronutrient deficiencies have also been found and should also be considered. Feeding difficulties is a common complaint in clinical practice, but limited data have been published in food allergy. Poor growth and reflux/vomiting have been shown to be associated with feeding difficulties, in particular in non-IgE-mediated food allergies. There seems to be a long-lasting effect on feeding, in particular in cow's milk allergy, which needs to be taken into account with dietary input. The interplay between growth, feeding difficulties and micronutrient deficiencies has been implied in some studies, but cause and effect is not well established and requires further research.

Pollution and respiratory disease: can diet or supplements help? A review

Pollution is known to cause and exacerbate a number of chronic respiratory diseases. The World Health Organisation has placed air pollution as the world's largest environmental health risk factor. There has been recent publicity about the role for diet and anti-oxidants in mitigating the effects of pollution, and this review assesses the evidence for alterations in diet, including vitamin supplementation in abrogating the effects of pollution on asthma and other chronic respiratory diseases. We found evidence to suggest that carotenoids, vitamin D and vitamin E help protect against pollution damage which can trigger asthma, COPD and lung cancer initiation. Vitamin C, curcumin, choline and omega-3 fatty acids may also play a role. The Mediterranean diet appears to be of benefit in patients with airways disease and there appears to be a beneficial effect in smokers however there is no direct evidence regarding protecting against air pollution. More studies investigating the effects of nutrition on rapidly rising air pollution are urgently required. However it is very difficult to design such studies due to the confounding factors of diet, obesity, co-morbid illness, medication and environmental exposure.

Effect of diet and maternal education on allergies among preschool children: A case-control study

INTRODUCTION

The prevalence of asthma and allergy has increased among children. This increase in prevalence might be related to dietary patterns.

AIMS

The present epidemiological study investigated the relationship between the consumption of fruit, vegetables, nuts, meat and fish, and the prevalence of wheeze, asthma, and eczema among preschool children.

METHODS

This nested case-control study included 1489 children aged 4-6 years and residing in Kaunas city, Lithuania. The subjects were recruited to the KANC newborn cohort study during 2007-2009. Parents' responses to questionnaires were used to collect information on allergic diseases, diet, and other variables. The association between dietary patterns and children's allergic diseases were tested by using logistic regressions, after adjustment for maternal education level, smoking during pregnancy, parental asthma, children's sex, parity, and antibiotic usage during the first year of life.

RESULTS

In this study, 83.3% of all children consumed fresh fruit and/or vegetables at least three times per week. A significantly lower adjusted odds ratio (aOR) of wheeze was found among children who ate fruit than among those who did not (aOR: 0.48; 95% CI: 0.22-0.96). The consumption of nuts was also associated with a lower 61% risk of eczema among 4-6 years old children.

CONCLUSION

The results indicated a beneficial effect of a frequent consumption of fresh fruit and nuts on the prevalence of allergies among children. These results might have important implications for children's health.

Low immune cell ARA and high plasma 12-HETE and 17-HDHA in iron-deficient South African school children with allergy

Allergy has been associated with altered fatty acid and inflammatory status. In this cross-sectional study of 321 rural iron deficient (ID) South African children (aged 6-11 years), a subsample (n=111) of children with parent-reported allergy data were divided into an allergic (n=30) and non-allergic (n=81) group and compared. PBMC arachidonic acid (ARA; P=0.010) and the PBMC ARA to dihomo-gamma-linolenic acid (DGLA) ratio (P=0.035) were lower in the allergic children. Plasma 12-hydroxyeicosatetraenoic acid and 17-hydroxydocosahexaenoic acid (17-HDHA) were higher (P=0.040 and 0.020, respectively) in the allergic group. Thus, a fatty acid composition and lipid mediator levels indicative of increased release of ARA from PBMC membranes, increased inflammation as well as the resolving thereof, were associated with parent-reported allergy symptoms. This study used baseline data of an intervention study which was registered at clinicaltrials.gov as NCT01092377.

Prenatal, perinatal, and childhood vitamin D exposure and their association with childhood allergic rhinitis and allergic sensitization

BACKGROUND

The role of early-life vitamin D in childhood allergy is controversial.

OBJECTIVE

We sought to assess vitamin D exposure in early life by multiple modalities and ascertain its association with childhood allergic rhinitis and allergic sensitization.

METHODS

One thousand two hundred forty-eight mother-child pairs from a US prebirth cohort unselected for any disease were studied. Vitamin D exposure was assessed by measures of maternal intake during the first and second trimesters of pregnancy and serum 25-hydroxyvitamin D (25[OH]D) levels in mothers during pregnancy, cord blood, and children at school age (median age, 7.7 years; interquartile range, 1.0 years). Tests for associations between vitamin D exposure with ever allergic rhinitis, serum total IgE level, and allergen sensitization at school age were conducted.

RESULTS

The correlations between maternal intake of vitamin D during pregnancy and serum 25(OH)D levels in pregnant mothers, cord blood, and children at school age were weak to moderate (r = -0.03 to 0.53). Each 100 IU/d of food-based vitamin D intake during the first and second trimesters (equivalent to the amount of vitamin D in an 8-ounce serving of milk) was associated with 21% and 20% reduced odds of ever allergic rhinitis at school age (odds ratios of 0.79 [95% CI, 0.67-0.92] and 0.80 [95% CI, 0.68-0.93]), respectively. There were no associations between maternal supplemental vitamin D intake or serum 25(OH)D levels at any time point with ever allergic rhinitis. There were no associations between any vitamin D exposure and serum total IgE level or allergen sensitization at school age.

CONCLUSIONS

Inclusion of foods containing vitamin D in maternal diets during pregnancy may have beneficial effects on childhood allergic rhinitis.

Maternal diet and its influence on the development of allergic disease

The early presentation of childhood allergies and the rise in their prevalence suggest that changes in early-life exposures may increase the predisposition. Very early-life exposures may act upon the developing foetal immune system and include infection, environmental tobacco smoke, other pollutants and nutrients provided via the mother. Three nutrients have come under close scrutiny: vitamin D, omega 3 polyunsaturated fatty acids (PUFAs) and folate (or the synthetic form, folic acid). Much of the data on these nutrients are observational although some randomised, placebo-controlled trials have been conducted with omega 3 PUFAs and one with vitamin D. Some studies with omega 3 PUFA supplements in pregnancy have demonstrated immunomodulatory effects on the neonate and a reduction in risk of early sensitisation to allergens. A few studies with omega 3 polyunsaturated fatty acid supplements in pregnancy have shown a reduction in proportion of children affected by allergic symptoms (food allergy) or in symptom severity (atopic dermatitis). Observational studies investigating the association of maternal vitamin D intake or maternal or neonatal vitamin D status have been inconsistent. One randomised, controlled trial of vitamin D supplementation during pregnancy did not show any significant effect on allergic outcome in the offspring. Studies investigating the association between maternal folic acid or folate intake or maternal or neonatal folate status and offspring risk of allergic disease have been equivocal. Further evidence is required to clarify whether increased intake of these nutrients during pregnancy influences allergic disease in the offspring. In the light of current evidence, mothers should not either increase or avoid consuming these nutrients to prevent or ameliorate allergic disease in their offspring. However, these essential nutrients each have important roles in foetal development. This is reflected in current government recommendations for intake of these nutrients by pregnant women.

A practical approach to vitamin and mineral supplementation in food allergic children

Background

The management of food allergy in children requires elimination of the offending allergens, which significantly contribute to micronutrient intake. Vitamin and mineral supplementation are commonly suggested as part of dietary management. However a targeted supplementation regime requires a complete nutritional assessment, which includes food diaries. Ideally these should be analysed using a computerised program, but are very time consuming. We therefore set out to evaluate current practice of vitamin and mineral supplementation in a cohort of children with non-Immunoglobulin E (IgE) mediated food allergies.

Methods

This prospective, observational study recruited children aged 4 weeks – 16 years, who required to follow an elimination diet for non-IgE mediated allergies. Only children that improved according to a symptom score and were on a vitamin and/or mineral supplement were included. A 3-day food diary including vitamin and mineral supplementation was recorded and analysed using Dietplan computer program. We assessed dietary adequacy with/without the supplement using the Dietary Reference Values.

Results

One hundred-and-ten children had completed food diaries and of these 29% (32/110) were taking vitamin and/or mineral supplements. Children on hypoallergenic formulas were significantly (p = 0.007) less likely to be on supplements than those on alternative over-the-counter milks. Seventy-one percent had prescribable supplements, suggested by a dietitian/physician. Sixty percent of those without a vitamin supplement had a low vitamin D intake, but low zinc, calcium and selenium was also common. Of the supplemented cohort many continued to be either under or over-supplemented.

Conclusion

This study has raised the question for the first time, whether clinicians dealing with paediatric food allergies should consider routine vitamin and/or mineral supplements in the light of deficient intake being so common in addition to being so difficult to predict.

Association between kimchi intake and asthma in Korean adults: the fourth and fifth Korea National Health and Nutrition Examination Survey (2007-2011)

This study was performed to investigate the relationship between dietary factors and asthma in a representative population-based sample of 19,659 men and women, aged 19-64 years, using data from the fourth and fifth Korean National Health and Nutrition Examination Survey (KNHANES), 2007-2011. The presence of asthma was based on self-reported physician diagnosis of asthma in the Health Interview Surveys. Food intake was estimated by trained interviewers using a 24-h recall method. The prevalence of asthma in Korean adults was 2.4%. Adults with asthma consumed fewer amounts of kimchi (P=.0444) and fish (P=.0175) but had a higher cereal intake than those without asthma (P=.0056). Multiple logistic regression analysis after controlling for confounding factors showed a significant inverse relationship between kimchi consumption and the prevalence of asthma [odds ratio (95% confidence interval) for subjects consuming 1 to <2 servings (40-79.9 g), 2 to <3 servings (80-119.9 g), and ≥3 servings (≥120 g), relative to those consuming <1 serving (<40 g): 0.726 (0.534-0.987), 0.506 (0.348-0.736), and 0.678 (0.502-0.916), respectively; P for trend=0.0131]. These results warrant future studies to explore the mechanisms responsible for the association between kimchi consumption and asthma.

Effects of antioxidant supplements and nutrients on patients with asthma and allergies

Asthma and allergic diseases have become a worldwide public health concern because of their increased prevalence. Despite decades of research on risk factors, the causes of these disorders are poorly understood. They are thought to develop through complex interactions between genetic and environmental factors. Because pulmonary and systemic oxidative stress increase inflammatory responses relevant to asthma and allergy, dietary or vitamin supplementation with antioxidants (a broad and varied category) has been proposed as an approach to reducing asthma incidence or morbidity. Meta-analyses of observational epidemiologic studies of variable methodological quality suggest associations of relatively low dietary intake of antioxidants and higher asthma and allergy prevalence. However, there have been few longitudinal studies of maternal or child dietary or vitamin/supplement antioxidant intake and asthma/allergy development. Moreover, there are no clinical trial data to support the use of dietary antioxidants or supplements to prevent asthma or allergy. A few small clinical trials suggest that specific antioxidants from diet or vitamin supplements might improve asthma control or lung function in asthmatic children or adults. Studies suggest that responses to antioxidants might be modified by life stage, genetic susceptibility, and environmental sources of oxidative stress. Large trials of antioxidant vitamin supplementation to prevent cancer suggest an increase in overall mortality with antioxidant vitamin supplementation, at least in populations with sufficient dietary antioxidant intake. This cautionary experience suggests that future trials to assess whether antioxidants reduce asthma incidence or improve asthma control should focus on supplementation of dietary sources of antioxidants. The potential benefits and risks of trials of vitamin supplements might be considered in special situations in which vulnerable populations have marked deficiency in dietary antioxidants, poor access to dietary antioxidants, and high exposure to environmental sources of oxidants.

Vitamin C prevents cigarette smoke-induced pulmonary emphysema in mice and provides pulmonary restoration

Vitamin C (VC) is a potent antioxidant and is essential for collagen synthesis. We investigated whether VC treatment prevents and cures smoke-induced emphysema in senescence marker protein-30 knockout (SMP30-KO) mice, which cannot synthesize VC. Two smoke-exposure experiments using SMP30-KO mice were conducted. In the first one (a preventive study), 4-month-old mice received minimal VC (0.0375 g/l) [VC(L)] or physiologically sufficient VC (1.5 g/l) [VC(S)] and exposed to cigarette smoke or smoke-free air for 2 months. Pulmonary evaluations followed when the mice were 6 months of age. The second study began after the establishment of smoke-induced emphysema (a treatment study). These mice no longer underwent smoke exposure but received VC(S) or VC(L) treatment for 2 months. Morphometric analysis was performed, and measurements of oxidative stress, collagen synthesis, and vascular endothelial growth factor in the lungs were evaluated. Chronic smoke exposure caused emphysema (29.6% increases of mean linear intercepts [MLI] and 106.5% increases of destructive index compared with the air-only group) in 6-month-old SMP30-KO mice, and this emphysema closely resembled human chronic obstructive pulmonary disease. Smoke-induced emphysema persisted in the VC(L) group after smoking cessation, whereas VC treatment provided pulmonary restoration (18.5% decrease of MLI and 41.3% decrease of destructive index compared with VC(L) group). VC treatment diminished oxidative stress, increased collagen synthesis, and improved vascular endothelial growth factor levels in the lungs. Our results suggest that VC not only prevents smoke-induced emphysema in SMP30-KO mice but also restores emphysematous lungs. Therefore, VC may provide a new therapeutic strategy for treating chronic obstructive pulmonary disease in humans.

Environment and asthma in adults

The present review addresses recent advances and especially challenging aspects regarding the role of environmental risk factors in adult-onset asthma, for which the causes are poorly established. In the first part of the review, we discuss aspects regarding some environmental risk factors for adult-onset asthma: air pollution, occupational exposures with a focus on an emerging risk represented by exposure to cleaning agents (both at home and in the workplace), and lifestyle and nutrition. The second part is focused on perspectives and challenges, regarding relevant topics on which research is needed to improve the understanding of the role of environmental factors in asthma. Aspects of exposure assessment, the complexity of multiple exposures, the interrelationships of the environment with behavioral characteristics and the importance of studying biological markers and gene-environment interactions to identify the role of the environment in asthma are discussed. We conclude that environmental and lifestyle exposures play an important role in asthma or related phenotypes. The changes in lifestyle and the environment in recent decades have modified the specific risk factors in asthma even for well-recognized risks such as occupational exposures. To better understand the role of the environment in asthma, the use of objective (quantitative measurement of exposures) or modern tools (bar code, GPS) and the development of multidisciplinary collaboration would be very promising. A better understanding of the complex interrelationships between socio-economic, nutritional, lifestyle and environmental conditions might help to study their joint and independent roles in asthma.

Mediterranean diet adherence during pregnancy and risk of wheeze and eczema in the first year of life: INMA (Spain) and RHEA (Greece) mother-child cohort studies

Maternal diet during pregnancy might influence the development of childhood allergic disorders. The aim of the present study was to evaluate the impact of Mediterranean diet (MD) adherence during pregnancy on wheeze and eczema in the first year of life in two population-based mother-child cohorts in Spain and Greece. We studied 1771 mother-newborn pairs from the Spanish multi-centre 'INMA' (INfancia y Medio Ambiente) study (Gipuzkoa, Sabadell and Valencia) and 745 pairs from the 'RHEA' study in Crete, Greece. The symptoms of wheeze and eczema were based on the criteria of the International Study of Asthma and Allergies in Childhood. Maternal diet during pregnancy was assessed by FFQ and MD adherence was evaluated through an a priori score. Multivariate log-binomial regression models were used to adjust for several confounders in each cohort and summary estimates were obtained by a meta-analysis. MD adherence was not associated with the risk of wheeze and eczema in any cohort, and similar results were identified in the meta-analysis approach. High meat intake (relative risk (RR) 1·22, 95 % CI 1·00, 1·49) and 'processed' meat intake (RR 1·18, 95 % CI 1·02, 1·37) during pregnancy were associated with an increased risk of wheeze in the first year of life, while a high intake of dairy products was significantly associated with a decreased risk of infantile wheeze (RR 0·83, 95 % CI 0·72, 0·96). The results of the present study show that high meat intake during pregnancy may increase the risk of wheeze in the first year of life, while a high intake of dairy products may decrease it.

Serum immunoglobulin E (IgE) levels and dietary intake of Korean infants and young children with atopic dermatitis

Atopic dermatitis (AD) has become a serious epidemic in Korean children. We aimed to investigate the association between vitamin C, E and other nutrients, and serum total IgE/specific IgE levels in children with AD. A total of 119 children (0-24 mo) diagnosed with AD were recruited for this cross-sectional study from a medical center in Seoul. A 24 h recall was used to assess dietary intakes. Serum total and six food-allergen specific IgE levels were measured by CAP-FEIA. Serum vitamin E was also measured but only in 25 out of the total 119 participants. Multiple linear regression analysis was performed to estimate the coefficients between serum IgE levels and dietary intake as well as serum vitamin E. Serum vitamin E levels showed a significantly inverse association with serum total IgE and all specific IgE levels (P < 0.05). Fat intake was inversely related with specific-IgEs for egg whites, milk, buck wheat, soy, and peanuts (P < 0.05). Positive associations were found between carbohydrate (CHO) intake and total IgE and specific IgEs to egg whites, milk, soy, and peanuts (P < 0.05). Vitamin C, E and n-3/n-6 fatty acids were not related with serum total IgE and specific IgE levels except for the association between buck wheat and vitamin E. In addition, there were no significant differences between males and females in dietary intake and serum IgE levels by student's t-test. Although dietary vitamin E showed no association with serum IgE levels, serum vitamin E drew a significant inverse relationship with serum IgE levels. The evidence seems to suggest that vitamin E may possibly lower total and specific-IgEs in children with AD, and that it is important to maintain a relatively high serum vitamin E level in children with AD.

Dietary factors associated with lifetime asthma or hayfever diagnosis in Australian middle-aged and older adults: a cross-sectional study

BACKGROUND

There is abundant research relevant to genetic and environmental influences on asthma and hayfever, but little is known about dietary risk factors in Australian adults. This study's purpose was to identify dietary factors associated with lifetime asthma (AS) and asthma or hayfever (AS/HF) diagnosis in Australian middle-aged and older adults.

METHODS

From The 45 and Up Study baseline self-report data, this study included 156,035 adult men and women. Participants were sampled from the general population of New South Wales, Australia in 2006-2009. About 12% of participants reported ever receiving an AS diagnosis (men 10%; women 14%) and 23% reported AS/HF diagnosis (men 19%; women 26%). Following principle components factor analysis, dietary items loaded onto one of four factors for men (meats/cheese; fruits/vegetables; poultry/seafood; grains/alcohol) or five factors for women (meats; fruits/vegetables; poultry/seafood; cereal/alcohol; brown bread/cheese). Logistic regression was used to analyze the associations between dietary factors and AS or AS/HF diagnosis.

RESULTS

For men, the meats/cheese factor was positively associated with AS (AOR = adjusted odds ratio for highest versus lowest quintile = 1.18, 95%CI = 1.08, 1.28; P(trend) = 0.001) and AS/HF (AOR for highest versus lowest quintile = 1.22, 95%CI = 1.14, 1.29; P(trend) < 0.001). Poultry/seafood was also associated with AS/HF in men (AOR for highest versus lowest quintile = 1.11, 95%CI = 1.04, 1.17; P(trend) = 0.002). For women, significant risk factors for AS/HF included meats (AOR for highest versus lowest quintile = 1.25, 95%CI = 1.19, 1.31; P(trend) = 0.001), poultry/seafood (AOR for highest versus lowest quintile = 1.06, 95%CI = 1.01, 1.12; P(trend) = 0.016), and fruits/vegetables (AOR for highest versus lowest quintile = 1.07, 95%CI = 1.02, 1.12; P(trend) = 0.011). In contrast, the cheese/brown bread dietary factor was protective against AS in women (AOR for highest versus lowest quintile = 0.88, 95%CI = 0.82, 0.94; P(trend) < 0.001).

CONCLUSIONS

Generally, diets marked by greater intakes of meats, poultry, and seafood were associated with diagnosed AS and AS/HF. Taken together, these findings suggest that adherence to a more meat-based diet may pose risk for AS and AS/HF in Australian adults.

Maternal plasma phosphatidylcholine fatty acids and atopy and wheeze in the offspring at age of 6 years

Variation in exposure to polyunsaturated fatty acids (PUFAs) might influence the development of atopy, asthma, and wheeze. This study aimed to determine whether differences in PUFA concentrations in maternal plasma phosphatidylcholine are associated with the risk of childhood wheeze or atopy. For 865 term-born children, we measured phosphatidylcholine fatty acid composition in maternal plasma collected at 34 weeks' gestation. Wheezing was classified using questionnaires at 6, 12, 24, and 36 months and 6 years. At age of 6 years, the children underwent skin prick testing, fractional exhaled nitric oxide (FENO) measurement, and spirometry. Maternal n-6 fatty acids and the ratio of n-3 to n-6 fatty acids were not associated with childhood wheeze. However, higher maternal eicosapentaenoic acid, docosahexaenoic acid, and total n-3 fatty acids were associated with reduced risk of non-atopic persistent/late wheeze (RR 0.57, 0.67 and 0.69, resp. P = 0.01, 0.015, and 0.021, resp.). Maternal arachidonic acid was positively associated with FENO (P = 0.024). A higher ratio of linoleic acid to its unsaturated metabolic products was associated with reduced risk of skin sensitisation (RR 0.82, P = 0.013). These associations provide some support for the hypothesis that variation in exposure to n-6 and n-3 fatty acids during pregnancy influences the risk of childhood wheeze and atopy.

A novel dietary intervention to optimize vitamin E intake of pregnant women to 15 mg/day

Associations have been reported between suboptimal maternal vitamin E intake during pregnancy and childhood asthma. This pilot study conducted in 2008/2009 investigated the feasibility and acceptability of a food-based randomized controlled trial in pregnant women to optimize dietary vitamin E intake to 15 mg/day. A food-based intervention using "food exchanges" to individually optimize dietary vitamin E intake to 15 mg/day was developed and included in an advice booklet. Forty-three pregnant women with a personal/partner history of asthma were recruited at 12 weeks gestation and randomized to food-based intervention or a control group until 20 weeks gestation. A registered dietitian assessed the vitamin E intake of 22 women and provided tailored advice on food-based exchanges to optimize their intake to 15 mg/day. The 21 control women were not given dietary advice. The food-based intervention was completed by 19 women and increased mean vitamin E intake: food diary data, 7.13 mg/day (95% confidence interval: 5.63 to 18.6) to 17.4 mg/day (95% confidence interval: 14.4 to 20.5) (P<0.001). This pilot study demonstrates the feasibility and acceptability of a food-exchange-based intervention to optimize dietary vitamin E intake during pregnancy. Additional work is required to determine whether this intervention, if sustained for the rest of pregnancy, reduces the likelihood of childhood asthma. The methodology used in the design of this novel food-based intervention could be transferred to other nutrients.

Increased intake of oily fish in pregnancy: effects on neonatal immune responses and on clinical outcomes in infants at 6 mo

BACKGROUND

Long-chain n-3 PUFAs found in oily fish may have a role in lowering the risk of allergic disease.

OBJECTIVE

The objective was to assess whether an increased intake of oily fish in pregnancy modifies neonatal immune responses and early markers of atopy.

DESIGN

Women (n = 123) were randomly assigned to continue their habitual diet, which was low in oily fish, or to consume 2 portions of salmon per week (providing 3.45 g EPA plus DHA) from 20 wk gestation until delivery. In umbilical cord blood samples (n = 101), we measured n-3 fatty acids, IgE concentrations, and immunologic responses. Infants were clinically evaluated at age 6 mo (n = 86).

RESULTS

Cord blood mononuclear cell (CBMC) production of interleukin (IL)-2, IL-4, IL-5, IL-10, and tumor necrosis factor-α in response to phytohemagglutinin (PHA) and of IL-2 in response to Dermatophagoides pteronyssinus allergen 1 (Derp1) was lower in the salmon group (all P ≤ 0.03). In the subgroup of CBMCs in which an allergic phenotype was confirmed in the mother or father, IL-10 production in response to Toll-like receptor 2, 3, and 4 agonists, ovalbumin, salmon parvalbumin, or Derp1 and prostaglandin E(2) production in response to lipopolysaccharide or PHA was lower in the salmon group (all P ≤ 0.045). Total IgE at birth and total IgE, incidence and severity of atopic dermatitis, and skin-prick-test positivity at 6 mo of age were not different between the 2 groups.

CONCLUSION

Oily fish intervention in pregnancy modifies neonatal immune responses but may not affect markers of infant atopy assessed at 6 mo of age. This trial is registered at clinicaltrials.gov as NCT00801502.

Serum micronutrient concentrations and childhood asthma: the PIAMA birth cohort study

BACKGROUND

Research suggests an influence of micronutrients on childhood asthma. So far, evidence mainly originates from cross-sectional studies using nutrient intake data, which is not an accurate measure of nutrient status. This study aimed to investigate the cross-sectional and prospective associations between serum concentrations of magnesium, vitamin D, selenium, and zinc and prevalence of (severe) asthma, atopy, and bronchial hyperresponsiveness (BHR) in childhood.

METHODS

In the Prevention and Incidence of Asthma and Mite Allergy birth cohort study, serum nutrient concentrations were available for a 4-yr-old subgroup (n = 372) and for a different 8-yr-old subgroup (n = 328). Yearly questionnaires inquired about asthma prevalence until 8 yr of age. Allergic sensitization was measured at 4 and 8 yr of age; BHR was measured at 8 yr of age. Data were analyzed with logistic regression and generalized estimating equations models.

RESULTS

There was a consistent (non-significant) inverse association between serum magnesium concentrations and asthma prevalence. Serum vitamin D concentrations measured at age 4 were inversely associated with asthma at ages 4-8 [e.g., cross-sectional association between vitamin D tertile 3 vs. 1 and severe asthma: odds ratio (OR): 0.49, 95% confidence interval (CI): 0.25-0.95], whereas vitamin D measured at age 8 was positively associated with asthma at age 8 (e.g., cross-sectional association between vitamin D tertile 3 vs. 1 and severe asthma: OR: 2.14, 95% CI: 0.67-6.82).

CONCLUSIONS

Our study contributes to the evidence that children with higher serum magnesium concentrations are less likely to have asthma. The associations between serum vitamin D concentrations and asthma were age-dependent.

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.

Nutrients and foods for the primary prevention of asthma and allergy: systematic review and meta-analysis

BACKGROUND

Epidemiologic studies suggest that deficiencies of the nutrients selenium; zinc; vitamins A, C, D, and E; and low fruit and vegetable intake may be associated with the development of asthma and allergic disorders.

OBJECTIVES

To investigate the evidence that nutrient and food intake modifies the risk of children developing allergy.

METHODS

We systematically searched 11 databases. Studies were critically appraised, and meta-analyses were undertaken.

RESULTS

We identified 62 eligible reports. There were no randomized controlled trials. Studies used cohort (n = 21), case-control (n = 15), or cross-sectional (n = 26) designs. All studies were judged to be at moderate to substantial risk of bias. Meta-analysis revealed that serum vitamin A was lower in children with asthma compared with controls (odds ratio [OR], 0.25; 95% CI, 0.10-0.40). Meta-analyses also showed that high maternal dietary vitamin D and E intakes during pregnancy were protective for the development of wheezing outcomes (OR, 0.56, 95% CI, 0.42-0.73; and OR, 0.68, 95% CI, 0.52-0.88, respectively). Adherence to a Mediterranean diet was protective for persistent wheeze (OR, 0.22; 95% CI, 0.08-0.58) and atopy (OR, 0.55; 95% CI, 0.31-0.97). Seventeen of 22 fruit and vegetable studies reported beneficial associations with asthma and allergic outcomes. Results were not supportive for other allergic outcomes for these vitamins or nutrients, or for any outcomes in relation to vitamin C and selenium.

CONCLUSION

The available epidemiologic evidence is weak but nonetheless supportive with respect to vitamins A, D, and E; zinc; fruits and vegetables; and a Mediterranean diet for the prevention of asthma. Experimental studies of these exposures are now warranted.

Maternal dietary pattern during pregnancy is not associated with recurrent wheeze in children

BACKGROUND

The rise in asthma prevalence over the last few decades may be a result of changes in prenatal or early-life environment, including maternal diet during pregnancy. Previous studies have found associations between individual foods or nutrients consumed during pregnancy and asthma or wheeze in children, but these may be confounded by overall dietary pattern.

OBJECTIVE

To determine whether overall maternal dietary pattern during pregnancy is associated with recurrent wheeze in children.

METHODS

A total of 1376 mother-infant pairs from Project Viva, a longitudinal prebirth cohort, who had responses for food frequency questionnaires in the first and second trimester and outcome data at 3 years of age were included. Multivariable logistic regression was used to look at associations between dietary pattern and the primary outcome of recurrent wheeze at 3 years. Overall dietary pattern was examined by using Mediterranean diet score, Alternate Healthy Eating Index modified for pregnancy (AHEI-P), and principal components analysis to look at Western and Prudent diets.

RESULTS

None of these dietary patterns was associated with the primary outcome of recurrent wheeze in children in either the crude or the multivariable model (multivariable model, odds ratio per 1-point increase in Mediterranean diet, 0.98 [95% CI, 0.89-1.08]; AHEI-P, 1.07 [0.87-1.30]; Prudent, 1.02 [0.83-1.26]; Western, 0.98 [0.81-1.19]).

CONCLUSION

Overall dietary pattern during pregnancy is not associated with recurrent wheeze in this cohort. Maternal intake of individual nutrients may be more important determinants of offspring wheeze-associated illness than is dietary pattern.

Complete lack of vitamin C intake generates pulmonary emphysema in senescence marker protein-30 knockout mice

Vitamin C (VC) is a potent antioxidant and plays an essential role in collagen synthesis. As we previously reported, senescence marker protein-30 (SMP30) knockout (KO) mice cannot synthesize VC due to the genetic disruption of gluconolactonase (i.e., SMP30). Here, we utilized SMP30 KO mice deprived of VC and found that VC depletion caused pulmonary emphysema due to oxidative stress and a decrease of collagen synthesis by the third month of age. We grew SMP30 KO mice and wild-type (WT) mice on VC-free chow and either VC water [VC(+)] or plain water [VC(−)] after weaning at 4 wk of age. Morphometric findings and reactive oxygen species (ROS) in the lungs were evaluated at 3 mo of age. No VC was detected in the lungs of SMP30 KO VC(−) mice, but their ROS increased 50.9% over that of the VC(+) group. Moreover, their collagen content in the lungs markedly decreased, and their collagen I mRNA decreased 82.2% compared with that of the WT VC(−) group. In the SMP30 KO VC(−) mice, emphysema developed [21.6% increase of mean linear intercepts (MLI) and 42.7% increase of destructive index compared with VC(+) groups], and the levels of sirtuin 1 (Sirt1) decreased 16.8%. However, VC intake increased the MLI 16.2% and thiobarbituric acid reactive substances 22.2% in WT mice, suggesting that an excess of VC can generate oxidative stress and may be harmful during this period of lung development. These results suggest that VC plays an important role in lung development through affecting oxidant-antioxidant balance and collagen synthesis.

Dietary patterns and adult asthma: population-based case-control study

BACKGROUND

Epidemiological studies of diet and asthma have focused on relations with intakes of individual nutrients and foods and evidence has been conflicting. Few studies have examined associations with dietary patterns.

METHODS

We carried out a population-based case-control study of asthma in adults aged between 16 and 50 in South London, UK. Information about usual diet was obtained by food frequency questionnaire and we used principal components analysis to define five dietary patterns in controls. We used logistic and linear regression, controlling for confounders, to relate these patterns to asthma, asthma severity, rhinitis and chronic bronchitis in 599 cases and 854 controls.

RESULTS

Overall, there was weak evidence that a 'vegetarian' dietary pattern was positively associated with asthma [adjusted odds ratio comparing top vs bottom quintile of pattern score 1.43 (95% CI: 0.93-2.20), P trend 0.075], and a 'traditional' pattern (meat and vegetables) was negatively associated [OR 0.68 (0.45-1.03), P trend 0.071]. These associations were stronger amongst nonsupplement users (P trend 0.030 and 0.001, respectively), and the association with the 'vegetarian' pattern was stronger amongst whites (P trend 0.008). No associations were observed with asthma severity. A 'prudent' dietary pattern (wholemeal bread, fish and vegetables) was positively associated with chronic bronchitis [OR 2.61 (1.13-6.05), P trend 0.025], especially amongst nonsupplement users (P trend 0.002).

CONCLUSIONS

Overall there were no clear relations between dietary patterns and adult asthma; associations in nonsupplement users and whites require confirmation. The finding for chronic bronchitis was unexpected and also requires replication.

[GA2LEN (Global Allergy and Asthma European Network), the perspective of the German speaking centers]

Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. GA2LEN (Global Allergy and Asthma European Network), an FP6 Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle allergy as a whole. GA2LEN benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA2LEN the world leader in the field. Besides these activities, research has been jointly made and the first papers are being published. GA2LEN achievements in general can be grouped as those for a durable infrastructure built up during the project phase those which are project-related work based on these novel infrastructures, and the development and implementations of guidelines. The major achievements of GA2LEN are reported in this paper.

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

BACKGROUND/OBJECTIVES

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

SUBJECTS/METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical practice: Breastfeeding and the prevention of allergy

The increase in allergic disease prevalence has led to heightened interest in the factors determining allergy risk, fueled by the hope that by influencing these factors one could reduce the prevalence of allergic conditions. The most important modifiable risk factors for allergy are maternal smoking behaviour and the type of feeding. A smoke-free environment for the child (to be), exclusive breastfeeding for 4-6 months and the postponement of supplementary feeding (solids) until 4 months of age are the main measures considered effective. There is no place for restricted diets during pregnancy or lactation. Although meta-analyses suggest that hypoallergenic formula after weaning from breastfeeding grants protection against the development of allergic disease, the evidence is limited and weak. Moreover, all current feeding measures aiming at allergy prevention fail to show effects on allergic manifestations later in life, such as asthma. In conclusion, the allergy preventive effect of dietary interventions in infancy is limited. Counselling of future parents on allergy prevention should pay attention to these limitations.

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.

Antioxidants and allergic disease: a case of too little or too much?

Speculation persists as to the possible role, if any, of dietary antioxidants in allergic disease. While it has been hypothesized that the recent increase in allergic disease is a consequence of declining dietary antioxidant intake, an alternative hypothesis proposes that the increase in allergic disease is due to increasing antioxidant intake. Dietary trends are conflicting; the intake of some antioxidants has declined, for others intakes are likely to have increased. Animal model studies demonstrate that antioxidant supplementation at the time of primary and subsequent allergen exposure attenuates allergic inflammatory responses. The data from human studies are less clear. Observational epidemiological studies of humans are beset by several methodological limitations associated with the assessment of diet and predominantly focus on asthma. Most observational studies report potentially beneficial associations between dietary antioxidants and allergic outcomes, but a small minority report potentially adverse associations. Human intervention studies suggest that single antioxidant supplements confer minimal, if any clinical benefit in adults with asthma, however, there is still scope for studies in children, atopic dermatitis, allergic rhinitis (AR) and of antioxidant combinations. More recently, it has been suggested that dietary antioxidants in the developmental context of fetal and infant development influence the development childhood asthma and atopic sensitization possibly by affecting the first interactions between the neonatal immune system and allergens. While a small number of birth cohort studies have reported potentially beneficial associations between maternal intake of some antioxidants during pregnancy and childhood asthma, there is very limited data suggesting associations between maternal antioxidant intake and childhood atopic dermatitis and AR. The available epidemiological, animal, molecular and immunological data suggest that there are associations between antioxidants and asthma and to a much lesser extent, atopic dermatitis and AR. However, the exact nature of the relationships and the potential for therapeutic intervention remain unclear.

[GA2LEN (Global Allergy and Asthma European Network)]

Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. GA2LEN (Global Allergy and Asthma European Network), an FP6 Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle Allergy in its globality. GA2LEN benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA2LEN the world leader in the field. Besides these activities, research has been jointly made and the first papers are being published. GA2LEN achievements in general can be grouped as those for a durable infrastructure built up during the project phase those which are project-related work based on these novel infrastructures, and the development and implementations of guidelines. The major achievements of GA2LEN are reported in this paper.

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

Objective

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

Design

Review of the literature.

Setting and results

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

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

Conclusions

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

Preventative effect of a flavonoid, enzymatically modified isoquercitrin on ocular symptoms of Japanese cedar pollinosis

BACKGROUND

Flavonoids are nutrients that exert anti-allergic effects. We investigated the preventative effect of enzymatically modified isoquercitrin (EMIQ), a flavonoid, to relieve the symptoms of Japanese cedar pollinosis.

METHODS

In a parallel-group, double-blind placebo-controlled study design, 24 subjects with Japanese cedar pollinosis took 100mg EMIQ or a placebo for 8 weeks, starting 4 weeks prior to the onset of pollen release. Subjective symptoms, ADL scores and the usage of drugs were recorded daily, and the QOL score was obtained every 4 weeks. Blood sampling was performed before and after the study to measure serum levels of IgE and flavonoids.

RESULTS

During the entire study period, ocular symptom + medication score for the EMIQ group was significantly lower (p < 0.05) than that of the placebo group. When limited to the period, ocular symptom scores (p < 0.05, weeks 5-6), and ocular congestion scores (p < 0.05, weeks 5-6) for the EMIQ group was significantly lower than that for the placebo group while other scores for the EMIQ group, such as ocular itching scores (p = 0.09, weeks 4-5), lacrimation scores (p = 0.07, weeks 5-6), and ocular congestion scores (p = 0.06, weeks 4-5), all tended to be lower. However no significant differences were found in nasal symptoms between the two groups. Serum concentrations of IgE were not significantly downregulated but the serum concentrations of quercetin and its derivatives were elevated significantly by the intake of EMIQ.

CONCLUSIONS

Intake of the quercetin glycoside EMIQ proved to be effective for the relief of ocular symptoms caused by Japanese cedar pollinosis.

GA2LEN (Global Allergy and Asthma European Network) addresses the allergy and asthma 'epidemic'

Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. The Global Allergy and Asthma European Network (GA(2)LEN), a Sixth EU Framework Program for Research and Technological Development (FP6) Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle allergy in its globality. The Global Allergy and Asthma European Network has benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA(2)LEN the world leader in the field. Besides these activities, research has also been carried out and the first papers are being published. Achievements of the Global Allergy and Asthma European Network can be grouped as follows: (i) those for a durable infrastructure built up during the project phase, (ii) those which are project-related and based on these novel infrastructures, and (iii) the development and implementation of guidelines. The major achievements of GA(2)LEN are reported in this paper.

Allergic respiratory diseases in the elderly

In industrialized countries there has been a significant increase in life expectancy, but chronic diseases are still important causes of death and disability in the elderly. Individuals over 65 years of age have a decrease in organic functions and lungs can lose more than 40% of their capacity. Although asthma and allergic rhinitis are more common in young people their prevalence in the elderly is increasing and the mortality reported in these patients is high. Asthmatic airways show an accumulation of activated eosinophils and lymphocytes determining structural changes of the bronchi. Local allergic inflammation, changes in T cell phenotypes and in apoptosis contribute to systemic inflammation. An increased risk of respiratory infections and neoplasic diseases has been recognized. These patients have increased susceptibility to atherosclerosis and cardiovascular diseases. Metabolic diseases are associated with an impairment of lung function and with systemic inflammation. Summing up older asthmatic patients have an increased risk to premature disability and death. A proper therapeutic approach to asthma can minimize this evolution. To identify the triggers is an important goal that allows reducing medication needs. Corticosteroids dampen allergic inflammation; therefore, they are the first choice in the treatment of patients with persistent asthma and rhinitis. Second-generation H1 receptor antagonists have reduced side effects and can be used if necessary. The elderly may have difficult access to health care. They should be educated about their disease and receive a written treatment plan. This information improves the quality of life, socialization and disease outcome in older people.

Diet and asthma: looking back, moving forward

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

Mediterranean diet is associated with reduced asthma and rhinitis in Mexican children

BACKGROUND

Diet during pregnancy and childhood has been suggested to play an important role in children's asthma risk. We assessed whether the adherence to a Mediterranean dietary pattern, for children in the last 12 months and their mothers during pregnancy, was associated with both childhood asthma and allergic rhinitis.

METHODS

A cross-sectional study was conducted in 2004 using a random sample of 1476 children (6- to 7-year old) from the Mexicali region, Mexico. Dietary data of children's intake in the last 12 months and their mothers' intake during pregnancy was collected, through a parental food frequency questionnaire. A Mediterranean diet score was computed [Trichopoulou et al., N Engl J Med 348 (2003), 2599]. Data on seven asthma and rhinitis-related outcomes were obtained from the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Adherence to a Mediterranean dietary pattern was inversely associated with asthma ever (OR = 0.60, 95% CI = 0.40-0.91), wheezing ever (0.64, 0.47-0.87), rhinitis ever (0.41, 0.22-0.77), sneezing ever (0.79, 0.59-1.07), current sneezing (0.71, 0.52-0.96) and current itchy-watery eyes (0.63, 0.42-0.95). No associations were found using the mothers' pregnancy diet score, except for current sneezing (0.71, 0.53-0.97).

CONCLUSIONS

Our findings suggest a protective effect of following a healthy dietary pattern on asthma and allergic rhinitis in Mexican children.

New visions in respiratory allergy (asthma and allergic rhinitis): an iPAC summary and future trends

In many aspects, respiratory allergies, i.e., allergic asthma and rhinitis, represent the hallmarks of allergy. Epidemiologic data highlight their large prevalence of most parts of the world, socioeconomic analysis reveal their large impact on global health and the large number of scientific publications in this field regularly brings to light many new aspects of these diseases. However, the current understanding of respiratory allergies, in particular in children remains scarce. How can we efficiently prevent respiratory allergies in allergy-prone infants? How can we prevent the progression of the disease? What therapeutic strategies could efficiently address efficient immunomodulation? the international Pediatric Allergy and Asthma Consortium, addressed these issues by a thorough review of the literature providing a state-of-the-art current knowledge in respiratory allergy, and identified a series of needs to be addressed in future studies.

A case-control study of the relation between plasma selenium and asthma in European populations: a GAL2EN project

BACKGROUND

There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma.

METHODS

The GA(2)LEN network has organized a multicentre case-control study in Europe to assess the relation of plasma selenium to asthma. The network compared 569 cases in 14 European centres with a diagnosis of asthma and reporting asthma symptoms in the last 12 months with 576 controls from the same centres with no diagnosis of asthma and no asthmatic symptoms in the last 12 months.

RESULTS

All cases and controls were selected from the same population defined by age and place of residence. Mean plasma selenium concentrations among the controls ranged from 116.3 microg/l in Palermo to 67.7 microg/l in Vienna and 56.1 microg/l among the children in Oslo. Random effects meta-analysis of the results from the centres showed no overall association between asthma and plasma selenium [odds ratio (OR)/10 microg/l increase in plasma selenium: 1.04; 95% confidence interval (CI): 0.89-1.21] though there was a significantly protective effect in Lodz (OR: 0.48; 95% CI: 0.29-0.78) and a marginally significant adverse effect in Amsterdam (OR: 1.68; 95% CI: 0.98-2.90) and Ghent (OR: 1.35; 95% CI: 1.03-1.77).

CONCLUSION

This study does not support a role for selenium in protection against asthma, but effect modification and confounding cannot be ruled out.

Lung function loss, smoking, vitamin C intake, and polymorphisms of the glutamate-cysteine ligase genes

RATIONALE

Smoking-induced oxidative stress contributes to chronic obstructive pulmonary disease, a lung disease characterized by low lung function and increasing mortality worldwide. The counterbalance for this effect may be provided by, for example, increased intake of the antioxidant vitamin C or endogenously acting antioxidant enzymes like glutamate-cysteine ligase (GCL), which is responsible for glutathione biosynthesis.

OBJECTIVES

To investigate associations of functional polymorphisms in GCL subunits (GCLM and GCLC) with lung function level and its longitudinal course, with vitamin C and smoking habits as potential interactive factors.

METHODS

Two independent general population samples (Doetinchem, n = 1,152, and Vlagtwedde-Vlaardingen, n = 1,390) with multiple lung function (FEV(1), VC) measurements were genotyped for three polymorphisms (C[-129]T, C[-588]T, and a trinucleotide GAG repeat [TNR]) in the subunits of GCL. Genetic effects on lung function level and decline were estimated using linear regression and linear mixed effect models adjusted for confounders. Findings were further investigated for interactions with vitamin C intake in the Doetinchem cohort.

MEASUREMENTS AND MAIN RESULTS

GCLC polymorphisms were significantly associated with lower lung function levels in interaction with pack-years smoked in both cohorts. TNR variants in GCLC were associated with accelerated FEV(1) decline in both cohorts in interaction with pack-years. All significant effects were specifically present in subjects within the lowest tertile of vitamin C intake.

CONCLUSIONS

GCLC is a novel susceptibility gene for low level of lung function in two independent populations. We provide suggestive evidence that this occurs due to an interaction between GCLC polymorphisms, smoking, and low vitamin C intake, which all contribute to the oxidative burden.

Early life nutrition and allergy

The gene/environment interactions that influence the development of allergic sensitisation and disease commence early in foetal life. The health, nutrition and environmental exposures of the mother during pregnancy have a profound effect not only on immune ontogeny but also on airway form and function. However, the influences on susceptibility to allergy may be different to those that affect manifestations of allergic disease such as asthma. A number of macro- and micro-nutrients have effects on either the risk of allergic sensitisation or allergic disease or both. Understanding the interactions will facilitate the identification of nutritional supplements which might lead to interventions which will prevent disease.

Diet, wheeze, and atopy in school children in Menorca, Spain

Epidemiological studies have shown inverse associations of asthma symptoms with fish, vegetable, and fruit intake. We evaluated the association between several dietary factors with wheeze and atopy among children in Menorca, a Spanish Mediterranean island. A cross-sectional analysis was performed on 460 children at age 6.5 yr. Parents completed a questionnaire on the child's respiratory and allergic symptoms, and a 96-item food frequency questionnaire. Children underwent skin prick tests with six common aeroallergens. The average daily intake was relatively high for fruits (177 g) and fish (54 g), and moderate for vegetables (59 g). A high consumption (>40 g/day) of fruity vegetables (tomatoes, eggplants, cucumber, green beans, zucchini) was found to have beneficial effect on current wheeze [odds ratio (OR), 0.38; 95% confidence interval (CI), 0.15-0.95, p < 0.05], and atopic wheeze with a significant decreasing trend when intake was increased (OR, 0.19; 95% CI, 0.04-0.95, p for trend = 0.04). No other fruits or vegetables were significantly associated with wheeze or atopy prevalence. An inverse association was found between a fish intake > or =60 g/day and atopy (OR, 0.43; 95% CI, 0.21-0.90, p < 0.05). The associations remained significant after adjustment for energy intake and maternal diet during pregnancy. Our results support a potential protective effect of fruity vegetables and fish intake during childhood on wheeze and atopy respectively.

Early life events in asthma--diet

It has been hypothesized that the recent increase in the prevalence of asthma may, in part, be a consequence of changing diet. There is now increasing interest in the possibility that childhood asthma may be influenced by maternal diet during pregnancy and/or diet during early childhood. A number of observational studies and a childhood fish oil supplementation study provide little support for the notion that early childhood intake of polyunsaturated fatty acids (PUFAs) influence the development of childhood asthma. Recent work however, suggests that supplementation of maternal diet with fish oil is associated with altered neonatal immune responses to allergens. Further work is required to establish whether this immunological observation is translated into clinical outcomes. Two birth cohorts have now reported reduced maternal intake of vitamin E, zinc and vitamin D during pregnancy to be associated with increased asthma and wheezing outcomes in children up to the age of 5 years. Early life diet could modulate the likelihood of childhood asthma by affecting fetal airway development and/or influencing the initial early life interactions between allergens and the immune system. In animal models, vitamin E, zinc and vitamin D have been shown to modify fetal lung development and vitamin E, zinc, vitamin D and PUFA can modulate T-cell responses. Further research, particularly, early life intervention studies need to be carried out to establish whether early life dietary intervention can be used as a public health measure to reduce the prevalence of childhood asthma.

Maternal fish intake during pregnancy and atopy and asthma in infancy

BACKGROUND

There is growing evidence that n-3 fatty acids have anti-inflammatory properties and may modulate immune response. Dietary intake of these nutrients during pregnancy could play a role in the risk of asthma and atopy in the offspring.

METHODS

Using data from a cohort of women (n=462) enrolled during pregnancy and whose offspring were followed up to 6 years, we evaluated the impact of fish consumption during pregnancy on the incidence of atopy and asthma. Dietary intake was assessed by food frequency questionnaire (42 items) applied by an interviewer.

RESULTS

Thirty-four percent of infants had a medical diagnosis of eczema at age 1 year, 14.3% of the children were atopic [based on skin prick test (SPT) at 6 years], and 5.7% had atopic wheeze at age 6 years. After adjusting for potential confounding factors, fish intake during pregnancy was protective against the risk of eczema at age 1 year, a positive SPT for house dust mite at age 6 years and atopic wheeze at age 6 years [odds ratio (OR)=0.73 95% confidence interval (CI) 0.55-0.98, OR=0.68, 95% CI 0.46-1.01 and OR=0.55, 95% CI 0.31-0.96, respectively]. For an increase in fish intake from once per week to 2.5 times per week, the risk of eczema at age 1 year decreased by 37%, and the risk of positive SPT at age 6 years by 35%. Stratification by breastfeeding showed that fish intake was significantly related to a decrease risk in persistent wheeze among non-breastfed children (P for interaction<0.05). No protective effect was observed among breastfed children.

CONCLUSION

Our data suggest a protective effect of fish intake during pregnancy on the risk of atopy-related outcomes.