Fruit and vegetable intake and risk of wheezing and asthma: a systematic review and meta-analysis

Diet and Asthma: Is It Time to Adapt Our Message?

Asthma is a chronic respiratory disorder which is associated with airway inflammation. Environmental factors, in association with genetic susceptibility, play a critical role in asthma pathophysiology. Inhaled allergens, smoke exposure, indoor and outdoor air pollution are common triggers of asthma symptoms. Although the role of diet has clearly established mechanisms in diseases such as cardiovascular disease, type 2 diabetes, and cancer, it is not commonly identified as a causal factor in asthma. However, some dietary patterns, such as the Western diet, which includes a high intake of refined grains, processed and red meats, and desserts, have pro-inflammatory effects. On the contrary, the Mediterranean diet, with high intake of fruits and vegetables has anti-inflammatory properties. The influence of food on asthma outcomes is of growing interest, but dietary habits of asthma patients are not commonly investigated in clinical practice. In this review, we focus on the impact of diet on asthma risk and asthma control. We also detail the influence of diet on obese patients with asthma.

Nutrition and Allergic Diseases

The development of IgE-mediated allergic diseases is influenced by many factors, including genetic and environmental factors such as pollution and farming, but also by nutrition. In the last decade, substantial progress has been made in our understanding of the impact that nutrition can have on allergic diseases. Many studies have addressed the effect of breastfeeding, pre-, pro- and synbiotics, vitamins and minerals, fiber, fruit and vegetables, cow's milk, and n-3 fatty acids, on the development of allergies. In addition, nutrition can also have indirect effects on allergic sensitization. This includes the diet of pregnant and breastfeeding women, which influences intrauterine development, as well as breastmilk composition. These include the diet of pregnant and breastfeeding women that influences intrauterine development as well as breastmilk composition, effects of food processing that may enhance allergenicity of foods, and effects via modulation of the intestinal microbiota and their metabolites. This editorial review provides a brief overview of recent developments related to nutrition and the development and management of allergic diseases.

Factors associated with the implementation of a vegetable and fruit program in a population of Australian elementary schools

Implementation of vegetable and fruit programs in schools is less than optimal. This study aimed to identify, using a theoretical framework, factors associated with implementation of a school vegetable and fruit program; that provides a time in class for children to consume a piece of vegetable or fruit they have brought from home. Three hundred and three randomly selected school principals across the state of New South Wales, Australia responded to a 25-min telephone survey. Principals were asked if their school had implemented a vegetable and fruit program, and which of 12 factors from Damschroder's consolidated framework for implementation research had facilitated or impeded implementation. Multiple logistic regression models examined the association between such factors and program implementation. Seventy-eight percent of schools had a vegetable and fruit program. Schools were significantly more likely to implement the program if the principal believed that: the program was effective (OR = 2.97; P < 0.02); they had sufficient resources to implement the program (OR = 4.22; P < 0.0001); the program would not be difficult to implement (OR = 10.16; P< 0.0001) and that the program was as important as other school priorities (OR = 2.45; P < 0.02). Realizing the intended benefits of vegetable and fruit programs requires widespread implementation by schools. Consideration of principal beliefs about the program effectiveness, resources, difficultly and relative importance in program implementation strategies appear key to increasing program implementation.

A Systematic Review of Technology-Based Dietary Intake Assessment Validation Studies That Include Carotenoid Biomarkers

Technological advances have allowed for the evolution of traditional dietary assessment methods. The aim of this review is to evaluate the accuracy of technology-based dietary assessment methods to determine carotenoid and/or fruit and vegetable intake when compared with carotenoid biomarkers. An online search strategy was undertaken to identify studies published in the English language up to July 2016. Inclusion criteria were adults ≥18 years, a measure of dietary intake that used information and communication technologies that specified fruit and/or vegetable intake or dietary carotenoid, a biomarker of carotenoid status and the association between the two. Sixteen articles from 13 studies were included with the majority cross-sectional in design (n = 9). Some studies used multiple dietary assessment methods with the most common: food records (n = 7), 24-h diet recalls (n = 5), food frequency questionnaires (n = 3) and diet quality assessed by dietary screener (n = 1). Two studies were directly web based, with four studies using technology that could be completed offline and data later transferred. Two studies utilised technology in the collection of dietary data, while the majority (n = 11) automated the collection in combination with nutrient analysis of the dietary data. Four studies provided correlation values between dietary carotenoids with biomarkers, ranging from r = 0.13 to 0.62 with the remaining studies comparing a measure of fruit and vegetable intake with biomarkers (r = 0.09 to 0.25). This review provides an overview of technology-based dietary assessment methods that have been used in validation studies with objectively measured carotenoids. Findings were positive with these dietary assessment measures showing mostly moderate associations with carotenoid biomarkers.

Is fruit and vegetable intake associated with asthma or chronic rhino-sinusitis in European adults? Results from the Global Allergy and Asthma Network of Excellence (GA2LEN) Survey

Background

Fruits and vegetables are rich in compounds with proposed antioxidant, anti-allergic and anti-inflammatory properties, which could contribute to reduce the prevalence of asthma and allergic diseases.

Objective

We investigated the association between asthma, and chronic rhino-sinusitis (CRS) with intake of fruits and vegetables in European adults.

Methods

A stratified random sample was drawn from the Global Allergy and Asthma Network of Excellence (GA²LEN) screening survey, in which 55,000 adults aged 15–75 answered a questionnaire on respiratory symptoms. Asthma score (derived from self-reported asthma symptoms) and CRS were the outcomes of interest. Dietary intake of 22 subgroups of fruits and vegetables was ascertained using the internationally validated GA²LEN Food Frequency Questionnaire. Adjusted associations were examined with negative binomial and multiple regressions. Simes procedure was used to control for multiple testing.

Results

A total of 3206 individuals had valid data on asthma and dietary exposures of interest. 22.8% reported having at least 1 asthma symptom (asthma score ≥1), whilst 19.5% had CRS. After adjustment for potential confounders, asthma score was negatively associated with intake of dried fruits (β-coefficient −2.34; 95% confidence interval [CI] −4.09, −0.59), whilst CRS was statistically negatively associated with total intake of fruits (OR 0.73; 95% CI 0.55, 0.97). Conversely, a positive association was observed between asthma score and alliums vegetables (adjusted β-coefficient 0.23; 95% CI 0.06, 0.40). None of these associations remained statistically significant after controlling for multiple testing.

Conclusion and clinical relevance

There was no consistent evidence for an association of asthma or CRS with fruit and vegetable intake in this representative sample of European adults.

Environmental Determinants of Bronchial Asthma among Saudi School Children in Southwestern Saudi Arabia

The aim here was to study the possible environmental and dietary determinants of asthma among school-aged children in Southwestern Saudi Arabia. In a cross-sectional study on a representative sample in Najran in Southwestern Saudi Arabia using an Arabic version of the modified ISAAC Phase III, parent-administered questionnaire data were collected. Skin prick tests (SPTs) were performed. The study included 1700 school children, out of them 468 (27.5%) were diagnosed with, cases of bronchial asthma and 20.8% (353) reported a 12-month nocturnal cough (as a proxy of severe asthma). In multivariable analysis, the study identified the following risk factors for having asthma or severe asthma: having dogs in the house, being male, being exposed to dense truck traffic on the street, using wood as a cooking fuel, conducting vigorous exercise, consuming eggs, consuming vegetables, having an allergic sensitization to dog hair, and being exposed to Cladosporium, pigweed, and Bermuda grass. On the other hand, the following food stuffs were found to be protective: seafood, fruit, and dairy products. Comprehensive school educational programs for both children and their parents should be adopted to prevent the use of wood in cooking and heating, to ensure that house pets are properly cared for, and to encourage proper dietary habits. Physicians should be informed of the patterns of allergens in order to improve asthma diagnosis and management.

Folate Deficiency, Atopy, and Severe Asthma Exacerbations in Puerto Rican Children

BACKGROUND

Little is known about folate and atopy or severe asthma exacerbations. We examined whether folate deficiency is associated with number of positive skin tests to allergens or severe asthma exacerbations in a high-risk population and further assessed whether such association is explained or modified by vitamin D status.

METHODS

Cross-sectional study of 582 children aged 6 to 14 years with (n = 304) and without (n = 278) asthma in San Juan, Puerto Rico. Folate deficiency was defined as plasma folate less than or equal to 20 ng/ml. Our outcomes were the number of positive skin tests to allergens (range, 0-15) in all children and (in children with asthma) one or more severe exacerbations in the previous year. Logistic and negative binomial regression models were used for the multivariate analysis. All multivariate models were adjusted for age, sex, household income, residential proximity to a major road, and (for atopy) case/control status; those for severe exacerbations were also adjusted for use of inhaled corticosteroids and vitamin D insufficiency (a plasma 25[OH]D < 30 ng/ml).

MEASUREMENTS AND MAIN RESULTS

In a multivariate analysis, folate deficiency was significantly associated with an increased degree of atopy and 2.2 times increased odds of at least one severe asthma exacerbation (95% confidence interval for odds ratio, 1.1-4.6). Compared with children who had normal levels of both folate and vitamin D, those with both folate deficiency and vitamin D insufficiency had nearly eightfold increased odds of one or more severe asthma exacerbation (95% confidence interval for adjusted odds ratio, 2.7-21.6).

CONCLUSIONS

Folate deficiency is associated with increased degree of atopy and severe asthma exacerbations in school-aged Puerto Ricans. Vitamin D insufficiency may further increase detrimental effects of folate deficiency on severe asthma exacerbations.

Frequency of food group consumption and risk of allergic disease and sensitization in schoolchildren in urban and rural China

BACKGROUND

Diet is a potential determinant of allergic diseases.

OBJECTIVE

To examine in schoolchildren the association between food intake and allergic diseases and determine whether there is effect of environment - rural vs. urban.

METHODS

A questionnaire survey was performed in 11 473 children aged 7-12 years in 20 schools from urban Guangzhou and rural Shaoguan, China. A nested case-control group, 402 from Guangzhou and 349 from Shaoguan, was recruited. Food ingestion frequency data were collected. Serum-specific IgE to 34 food and airborne allergens was determined. Associations between food ingestion frequency and clinical outcomes were sought by logistic analyses.

RESULTS

The prevalence of self-reported asthma (6.6% vs. 2.5%), rhinitis (23.2% vs. 5.3%) and eczema (34.1% vs. 25.9%) was significantly higher in Guangzhou subjects compared to Shaoguan, whereas prevalence of food hypersensitivity (9.7% vs. 9.2%) and food allergy (4.0% vs. 3.5%) was not significantly different. In this case-control study, seafood and fruits were two major food groups causing food hypersensitivity. Urban children consumed more milk, egg, chocolate, fruits, vegetable and cereals compared to rural children. Significantly higher percentage of Guangzhou children was sensitized to egg and milk, whereas more Shaoguan children were sensitized to seafood, nuts and seeds, fruit, vegetables, legumes and cereals. High consumption of milk (OR 2.604, 95 CI% 1.569-4.322, P < 0.001) and vegetables (OR 0.382, 95% CI 0.180-0.809, P = 0.012) were positively and reversely associated with asthma, respectively.

CONCLUSION

Difference in prevalence of asthma but not food allergy was observed. Diets of schoolchildren are affected by disease-related modification and country's urbanization. High vegetable intake and low milk intake might protect against asthma.

Barriers and Facilitators to Improve Fruit and Vegetable Intake Among WIC-Eligible Pregnant Latinas: An Application of the Health Action Process Approach Framework

OBJECTIVE

Identify barriers and facilitators to improve prenatal fruit and vegetable (F&V) intake among Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)-eligible Latinas using the Health Action Process Approach framework.

DESIGN

Qualitative data were collected via audiotaped in-depth interviews as part of a larger study to design an intervention to increase prenatal F&V intake.

SETTING

Hartford, Connecticut.

PARTICIPANTS

Forty-five WIC-eligible Latinas completed the study. Included women were: ≥ 18 years old; in 2nd or 3rd trimester; having a singleton pregnancy; overweight or obese (ie, pregravid body mass index ≥ 25); not on a restricted diet; nonsmokers.

PHENOMENON OF INTEREST

Prenatal factors that promote and hinder F&V intake.

ANALYSIS

Transcripts were independently read and coded, and a consensus was reached about emerging themes.

RESULTS

Ten factors influenced prenatal F&V intake: social support, family structure, F&V access, F&V preferences, F&V knowledge, F&V health outcome expectations, self-efficacy, intentions, F&V action/coping planning strategies, and maternal health status.

CONCLUSIONS AND IMPLICATIONS

Social support from family/friends emerged as the primary distal factor driving prenatal F&V intake. Interventions designed to empower pregnant Latinas to gain the access, confidence, knowledge, and strategies necessary to consume more F&Vs must consider strengthening support to achieve the desired outcome.

Risk and Protective Factors for Childhood Asthma: What Is the Evidence?

To summarize the principal findings on risk and protective factors for childhood asthma, we retrieved systematic reviews on these topics in children (aged 1 to 18 years), up to January 2016, through MEDLINE, EMBASE, CINAHL, SCOPUS, and CDSR. A total of 227 studies were searched from databases. Among those, 41 systematic reviews (SRs) were included: 9 focused on prenatal factors, 5 on perinatal factors, and 27 on postnatal factors. Of these 41 SRs, 83% had good methodological quality, as determined by the Assess Systematic Reviews tool. After reviewing all evidence, parental asthma, prenatal environmental tobacco smoke, and prematurity (particularly very preterm birth) are well-established risk factors for childhood asthma. Current findings do suggest mild-to-moderate causal effects of certain modifiable behaviors or exposures during pregnancy (maternal weight gain or obesity, maternal use of antibiotics or paracetamol, and maternal stress), the perinatal period (birth by Caesarean delivery), or postnatal life (severe respiratory syncytial virus infection, overweight or obesity, indoor exposure to mold or fungi, and outdoor air pollution) on childhood asthma, but this suggestive evidence must be confirmed in interventional studies or (if interventions are not feasible) well-designed prospective studies.

Maternal nutrition during pregnancy and risk of asthma, wheeze, and atopic diseases during childhood: a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies suggest a relationship between maternal nutrition during pregnancy and the occurrence of asthma and atopic conditions during childhood. However, individual study results are conflicting. The objective of this meta-analysis was to critically examine the current evidence for an association between nutrition (dietary patterns, food groups, vitamins, or oligo-elements) ingestion during pregnancy and asthma, wheeze, or atopic conditions in childhood.

METHODS

The inclusion criteria were as follows: (i) systematic recording of diet during the gestational period and (ii) documentation of asthma, wheezing, eczema, or other atopic disease in the offspring. The primary outcomes were prevalence of asthma or wheeze among the offspring during childhood; and secondary outcomes were prevalence of eczema, allergic rhinitis, or other atopic conditions.

RESULTS

We found 120 titles, abstracts, and citations, and 32 studies (29 cohorts) were included in this analysis. Data on vitamins, oligo-elements, food groups, and dietary patterns during pregnancy were collected. A meta-analysis revealed that higher maternal intake of vitamin D [odds ratio (OR) = 0.58, 95% confidence interval (CI) = 0.38-0.88], vitamin E (OR = 0.6, 95% CI = 0.46-0.78), and zinc (OR = 0.62, 95% CI = 0.40-0.97) was associated with lower odds of wheeze during childhood. However, none of these or other nutrients was consistently associated with asthma per se or other atopic conditions.

CONCLUSIONS

Current evidence suggests a protective effect of maternal intake of each of three vitamins or nutrients (vitamin D, vitamin E, and zinc) against childhood wheeze but is inconclusive for an effect on asthma or other atopic conditions.

Sulforaphane improves the bronchoprotective response in asthmatics through Nrf2-mediated gene pathways

Background

It is widely recognized that deep inspiration (DI), either before methacholine (MCh) challenge (Bronchoprotection, BP) or after MCh challenge (Bronchodilation, BD) protects against this challenge in healthy individuals, but not in asthmatics. Sulforaphane, a dietary antioxidant and antiinflammatory phytochemical derived from broccoli, may affect the pulmonary bronchoconstrictor responses to MCh and the responses to DI in asthmatic patients.

Methods

Forty-five moderate asthmatics were administered sulforaphane (100 μmol daily for 14 days), BP, BD, lung volumes by body-plethsmography, and airway morphology by computed tomography (CT) were measured pre- and post sulforaphane consumption.

Results

Sulforaphane ameliorated the bronchoconstrictor effects of MCh on FEV₁ significantly (on average by 21 %; p = 0.01) in 60 % of these asthmatics. Interestingly, in 20 % of the asthmatics, sulforaphane aggravated the bronchoconstrictor effects of MCh and in a similar number was without effect, documenting the great heterogeneity of the responsiveness of these individuals to sulforaphane. Moreover, in individuals in whom the FEV₁ response to MCh challenge decreased after sulforaphane administration, i.e., sulforaphane was protective, the activities of Nrf2-regulated antioxidant and anti-inflammatory genes decreased. In contrast, individuals in whom sulforaphane treatment enhanced the FEV₁ response to MCh, had increased expression of the activities of these genes. High resolution CT scans disclosed that in asthmatics sulforaphane treatment resulted in a significant reduction in specific airway resistance and also increased small airway luminal area and airway trapping modestly but significantly.

Conclusion

These findings suggest the potential value of blocking the bronchoconstrictor hyperresponsiveness in some types of asthmatics by phytochemicals such as sulforaphane.

Diet and asthma: an update

PURPOSE OF REVIEW

Our objective was to provide an overview and discussion of recent experimental studies, epidemiologic studies, and clinical trials of diet and asthma. We focus on dietary sources and vitamins with antioxidant properties [vitamins (A, C, and E), folate, and omega-3 and omega-6 polyunsaturated fatty acids (n-3 and n-6 PUFAs)].

RECENT FINDINGS

Current evidence does not support the use of vitamin A, vitamin C, vitamin E, or PUFAs for the prevention or treatment of asthma or allergies. Current guidelines for prenatal use of folate to prevent neural tube defects should be followed, as there is no evidence of major effects of this practice on asthma or allergies. Consumption of a balanced diet that is rich in sources of antioxidants (e.g. fruits and vegetables) may be beneficial in the primary prevention of asthma.

SUMMARY

None of the vitamins or nutrients examined is consistently associated with asthma or allergies. In some cases, further studies of the effects of a vitamin or nutrient on specific asthma phenotypes (e.g. vitamin C to prevent viral-induced exacerbations) are warranted. Clinical trials of 'whole diet' interventions to prevent asthma are advisable on the basis of existing evidence.

Asthma control in pregnancy is associated with pre-conception dietary patterns

OBJECTIVE

To examine pre-conception dietary patterns in pregnant asthmatic women and to identify associations between maternal diet and asthma control during pregnancy.

DESIGN

Cross-sectional study. Pre-conception food frequency data were collected retrospectively. Asthma control was assessed using the Global Initiative for Asthma guidelines. Dietary patterns were derived using factor analysis. Binary logistic regression analyses were used to test the association between uncontrolled asthma and each dietary pattern (Z-score), with values presented as odds ratio and 95 % confidence interval.

SETTING

Antenatal clinic in a tertiary hospital, Adelaide, Australia, May 2009-July 2013.

SUBJECTS

One hundred and fifty-eight asthmatic pregnant women.

RESULTS

Three dietary patterns were identified: (i) 'high protein/fruit' (strong food group loadings for fish, meat, chicken, fruit); (ii) 'high fat/sugar/takeaway' (takeaway foods, crisps, refined grains); and (iii) 'vegetarian-type' (vegetables, fruit, soya milk, whole grains). A 1 sd increase in score on the high fat/sugar/takeaway pattern was associated with increased likelihood of uncontrolled asthma (adjusted OR=1·54; 95 % CI 1·07, 2·23; P=0·022). Women with uncontrolled asthma (n 115) had higher energy-adjusted intakes of saturated fat, monounsaturated fat, carbohydrate, sugar and fibre compared with women with controlled asthma (n 43, all P≤0·05).

CONCLUSIONS

Pre-pregnancy dietary patterns may influence maternal asthma control. Our work highlights the importance of achieving a healthy diet before pregnancy that is low in saturated fat, sugar and takeaway foods, and therefore higher in lean meats, poultry and fish, as well as fruits, vegetables and whole grains. A healthy dietary pattern should be encouraged in all asthmatic women who are of childbearing age, and should additionally be promoted before pregnancy and beyond.

Nutrition and respiratory health--feature review

Diet and nutrition may be important modifiable risk factors for the development, progression and management of obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). This review examines the relationship between dietary patterns, nutrient intake and weight status in obstructive lung diseases, at different life stages, from in-utero influences through childhood and into adulthood. In vitro and animal studies suggest important roles for various nutrients, some of which are supported by epidemiological studies. However, few well-designed human intervention trials are available to definitively assess the efficacy of different approaches to nutritional management of respiratory diseases. Evidence for the impact of higher intakes of fruit and vegetables is amongst the strongest, yet other dietary nutrients and dietary patterns require evidence from human clinical studies before conclusions can be made about their effectiveness.

Effects of the flavanone combination hesperetin-naringenin, and orange and grapefruit juices, on airway inflammation and remodeling in a murine asthma model

We investigated whether flavanones, hesperetin-naringenin, orange, and grapefruit juices reduce airway inflammation and remodeling in murine chronic asthma model. To establish chronic asthma, mice received house dust mite (HDM) for 3 days in 2 weeks, followed by twice per week for 4 weeks. Concurrently, during the last 4 weeks, mice received hesperetin plus naringenin (HN), orange plus grapefruit juice (OGJ), orange juice (OJ), or grapefruit juice (GJ); whereas the asthmatic control (AC) group and non-asthmatic control (NC) group consumed water ad libitum. In histopathological examination, no goblet cells metaplasia was observed in the HN, OJ, and GJ groups; also, intra-alveolar macrophages decreased compared with those of the AC group. Hesperetin plus naringenin significantly decreased subepithelial fibrosis, smooth muscle hypertrophy in airways, and lung atelectasis compared with the AC group. Also, there was a reduction of subepithelial fibrosis in airways in OJ and GJ groups compared with AC group, but it was not noticed in OGJ group. In bronchoalveolar lavage fluid, macrophages numbers decreased in OJ and OGJ groups, whereas eosinophil numbers were increased in OJ group compared with NC group. Our finding revealed that hesperetin plus naringenin ameliorate airway structural remodeling more than orange juice and grapefruit juice in murine model of HDM-induced asthma.

Personalising nutritional guidance for more effective behaviour change

Improving diet and other lifestyle behaviours has considerable potential for reducing the global burden of non-communicable diseases, promoting better health across the life-course and increasing wellbeing. However, realising this potential will require the development, testing and implementation of much more effective behaviour change interventions than are used conventionally. Evidence-based, personalised (or stratified) interventions which incorporate effective behaviour change techniques (BCT) and which are delivered digitally are likely to be an important route to scalable and sustainable interventions. Progress in developing such interventions will depend on the outcomes of research on: (i) the best bases for personalisation of dietary advice; (ii) identification of BCT which are proven to enhance intervention efficacy; (iii) suitable platforms (digital-based tools) for collection of relevant participant characteristics (e.g. socioeconomic information, current diet and lifestyle and dietary preferences) linked with intelligent systems which use those characteristics to offer tailored feedback and advice in a cost-effective and acceptable manner. Future research should focus on such interventions aiming to reduce health inequalities and to improve overall public health.

Factors associated with asthma in adolescents in the city of Fortaleza, Brazil

OBJECTIVE

Asthma is a chronic inflammatory airway disease. In Brazil, little is known about factors associated with this disease. This study aimed to identify factors associated with asthma in 13- to 14-year-old adolescents in Fortaleza, Ceará, Brazil.

METHODS

It is a cross-sectional population-based study, with a probability sample of 3015 students in 2006-2007. We used the questionnaires about asthma, rhinitis and socio-demographic/environmental factors from the International Study for Asthma and Allergies in Childhood (ISAAC) protocol. Current asthma was defined as physician-diagnosed asthma and wheezing in the previous 12 months. Bivariate analysis was performed between asthma and factors included in the study, using prevalence ratio and Chi-square test. Confidence intervals (95%) and odds ratio (OR) were also calculated. Factors associated with asthma in bivariate analysis were then assessed using logistic regression.

RESULTS

Final sample was composed by 694 adolescents, 179 with asthma. Rhinoconjunctivitis and consumption of stuffed biscuits and fried snacks three or more times per week were independently and positively associated with asthma; consumption of fruits three or more times per week was negatively associated with asthma.

CONCLUSIONS

Dietary factors were the most associated with asthma in this study. Besides rhinoconjunctivitis, consumption of stuffed biscuits and fried snacks (foods with high content of saturated fat) three or more times per week were independently associated with asthma as aggravating factors, while the consumption of fruits three or more times per week was associated with asthma as protective factor. Interventions acting on these factors may decrease the occurrence of asthma in this population.