Parental Education and the Association between Fruit and Vegetable Consumption and Asthma in Adolescents: The Greek Global Asthma Network (GAN) Study

Greater fruit and vegetables consumption, and adherence to a Mediterranean type of diet reduces the risk for asthma in children; a systematic review and meta-analysis

The objective of this study was to explore the relationship between the consumption of fruits, vegetables and adherence to the Mediterranean diet with childhood asthma development and severity. A systematic literature search and synthesis of the results was performed throughout the last two decades. A total of 45 studies were analysed and 392,797 children were included. Greater adherence to a Mediterranean type of diet was inversely associated with asthmatic outcomes (OR:0.71,95% CI:0.54,0.88). Regarding fruits, vegetables consumption, a significant inverse association between increased fruits or vegetable intake and asthma was found (OR:0.82,95% CI:0.77,0.86; 0.84,95% CI:0.77,0.91, respectively). Fruits and vegetables consumption combined was also inversely related to all asthmatic outcomes (OR:0.65,95% CI:0.49,0.78). The level of heterogeneity was moderate-to-high (30%-97%). The present review and meta-analysis show a trend to an inverse association between adherence to the Mediterranean diet or a healthy diet rich in fruits and vegetables and the occurrence of childhood asthma but with a low level of certainty.

The Effects of a Healthy Diet on Asthma and Wheezing in Children and Adolescents: A Systematic Review and Meta-Analysis

Background

Asthma is a public health problem requiring focused attention. This study aimed to systematically evaluate the association between dietary structure and asthma or wheezing in children.

Methods

The study protocol of this meta-analysis has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) with the registration code CRD42023390191. A total of 8397 articles were retrieved, searching PubMed, Medline, Embase, Web of Science, and Scopus databases as of November 21, 2022. Two independent authors were responsible for independently conducting the literature screening process. Effect-size estimates were expressed as odds ratio (OR) in cross-sectional studies and risk ratio (RR) in cohort studies with a 95% confidence interval (CI). Summary effect estimates were evaluated with random-effect models. Meanwhile, subgroup and sensitivity analyses were performed to assess the potential sources of heterogeneity and the robustness of the pooled estimation.

Results

A total of 65 studies, including 567,426 subjects had been analyzed. Overall analyses of cross-sectional studies revealed that a healthy diet was protective against asthma (adjusted OR=0.85, 95% CI: 0.80-0.89, P <0.001, I2=69.8%, Tau2=0.026) and wheezing (adjusted OR=0.85, 95% CI: 0.81-0.89, P <0.001, I2=66.8%, Tau2=0.015) in children and adolescents. Conversely, unhealthy diets can exacerbate asthma (adjusted OR=1.28, 95% CI: 1.20-1.36, P <0.001, I2=64.9%, Tau2=0.019) and wheeze (adjusted OR=1.09, 95% CI: 1.02-1.16, P =0.006, I2=75.2%, Tau2=0.023) in children and adolescents. The same trend was found in cohort studies (adjusted RR=0.72, 95% CI: 0.58-0.90, P =0.003, I2=83.5%, Tau2=0.105). A clear trend was observed between high-frequency healthy diets (OR=0.80; 95% CI: 0.71-0.89; P <0.001) is more protective against asthma than low-frequency healthy diets (OR=0.81; 95% CI: 0.70-0.94; P =0.007).

Conclusion

Our findings highlight the protective effects of a healthy diet on asthma and wheezing in children, including fruit, seafood, cereals, and the Mediterranean diet.

Dietary Factors May Delay Tolerance Acquisition in Food Protein-Induced Allergic Proctocolitis

BACKGROUND

Dietary and environmental factors may influence tolerance acquisition in food protein-induced allergic proctocolitis (FPIAP). This retrospective observational study explored the role of maternal diet during pregnancy and breastfeeding in tolerance acquisition in infantile FPIAP.

METHODS

Breastfed infants with FPIAP from six diverse regions in Greece were divided into two groups, based on development of tolerance to the trigger food: Group A (n = 43), before, and Group B (n = 53), after, the 6th month of age. Maternal diet during pregnancy and breastfeeding was elicited using the Mediterranean Diet Score Questionnaire and the Mediterranean Oriented Culture Specific Semi-Quantitative Food Frequency Questionnaire.

RESULTS

Mean age at diagnosis of FPIAP (1.5 months) and weaning (5.5 months) were the same in both groups. The main trigger was cow's milk. Group A received infant milk formula earlier than Group B. Group B had a higher incidence of asthma/wheeze, siblings with milk allergy, maternal smoking and rural residence. On multivariate analysis, earlier resolution of FPIAP was associated with higher maternal education and with salt intake and consumption of goat/sheep cheese during pregnancy and olive oil during breastfeeding. Consumption of multivitamins during pregnancy and meat, winter fruits, green vegetables, butter, salt, "ready-to-eat" meals and pastries during breastfeeding were correlated with longer duration of symptoms.

CONCLUSIONS

Mothers of children with FPIAP to cow's milk protein can be advised to eat more yogurt, cheese and olive oil during subsequent pregnancies, and avoid multivitamins, grilled food, "ready-to-eat" meals, pastries, meat and alcohol during breastfeeding, to reduce the duration of FPIAP presenting in future infants.

Advances in Research on Nutrition and Childhood Obesity

Obesity is a complex, multifactorial problem affecting children and adolescents around the world [...].

Food Protein-Induced Allergic Proctocolitis: The Effect of Maternal Diet During Pregnancy and Breastfeeding in a Mediterranean Population

Background

The aim of the current investigation was to explore the association of food protein-induced allergic proctocolitis (FPIAP) with the maternal diet during pregnancy and breastfeeding in Greek infants.

Methods

A multicenter retrospective case-control study was conducted in 6 regions in Greece, with 96 mothers of infants with and 141 mothers of infants without a history of FPIAP. Maternal dietary habits during pregnancy and breastfeeding were evaluated with the following validated questionnaires: (a) The Mediterranean Diet Score and (b) The Mediterranean Oriented Culture-Specific Semi-Quantitative Food Frequency Questionnaire.

Results

FPIAP was associated with cow's milk (83.6%), egg (7.3%), wheat (6.4%), and beef (6.4%) in the maternal diet. Adherence to Mediterranean Diet was similar among the mothers. Mothers of FPIAP infants consumed more vegetables. Elastic net prediction models showed that, in this Mediterranean population, increased consumption during pregnancy and lactation of common allergens, whole grain products, homemade food, fish and shellfish, and fruits was associated with a decreased risk of FPIAP. Conversely, a high intake of vegetables, sugar and total fat, and non-stick/grilled cooking, were associated with increased risk of FPIAP, as was a high intake of salt and white flour during lactation only.

Conclusions

Components of a maternal Mediterranean Diet may protect against FPIAP when traditional cooking methods are adopted and fish, fruit, and whole wheat products are consumed frequently during pregnancy and breastfeeding.

Parental education moderates the association between indoor moisture environment and asthma in adolescents: the Greek Global Asthma Network (GAN) cross-sectional study

Objective

Asthma is a major contributor to childhood morbidity. Several environmental and socioeconomic status (SES) factors have been implicated in its etiopathogeneses such as indoor moisture and parental education level. Our study examined the association between exposure to indoor dampness and/or mould (IDM) with adolescent asthma and how parental education could modify or mediate this relationship.

Method

A total of 1934 adolescents (boys: 47.5%, mean age (standard variation): 12.7(0.6) years) and their parents were voluntarily enrolled and completed a validated questionnaire on adolescents’ asthma status, parental educational level, and adolescents’ indoor exposure to IDM during three different lifetime periods, i.e., pregnancy, the first year of life and the current time.

Results

There was a significant modification effect of parental education only for the current exposure; higher parental education lowered almost 50% the odds of IDM and asthma (adjusted odds ratio (aOR): 1.96, 95% Confidence Intervals (CI): (1.05–3.68) and aOR:1.55, 95% CI (1.04–2.32), for primary/secondary and tertiary parental education, respectively).

Conclusion

Adolescents whose parents had a higher education level had lesser odds to have asthma, even if they were exposed to a moisture home environment. This could be attributed to the increased knowledge about asthma risk factors and the improved measures for the amelioration of moisture-home environment that highly educated parents are more likely to take. Further research is needed in order to elucidate the interweaved role of family SES in the aforementioned relation.

Exploring the Relation between Atopic Diseases and Lifestyle Patterns among Adolescents Living in Greece: Evidence from the Greek Global Asthma Network (GAN) Cross-Sectional Study

Introduction: Diet and physical activity might be associated with the risk of allergic diseases in childhood. However, evidence in literature is sparse and diverse. We aim to examine the associations between four healthy dietary consumption pattern drinks, plus the adherence to a physically active lifestyle with atopic diseases (asthma, allergic rhinitis and eczema) in adolescence and their relative importance. Methods: A total of 1934 adolescents (921 boys, 47.5%) and their parents completed a validated questionnaire assessing atopic diseases’ symptoms prevalence in the past 12 months, as well as nutritional and physical activity information. Four healthy dietary and one physical active lifestyle patterns were identified and logistic regression was applied to assess their relation with allergic diseases. Results: A high weekly consumption of fruits, vegetables and pulses and low consumption of unhealthy foods was negatively associated with all atopic symptoms while adherence to a physical active lifestyle was inversely associated with asthma and allergic rhinitis symptoms and dairy products with asthma and eczema symptoms in the past 12 months after adjustment for several confounders (all p < 0.05). Fruits, vegetables and pulses consumption per week emerged as the most important lifestyle pattern negatively associated for all atopic diseases, after the adjustment for all the remaining lifestyle patterns and confounders (all p < 0.05) Conclusions: Our findings suggest that a high fruit, vegetable and pulse intake should be the first lifestyle intervention every clinician and public health care worker evolving in the management of atopic adolescents should encourage and promote.