Background: Associations between maternal vitamin E, vitamin D and zinc intakes during pregnancy and asthma, wheeze and eczema in 5-year-old children have previously been reported. A study was undertaken to investigate whether maternal intake of specific foods during pregnancy is associated with asthma and allergic outcomes in the same children. Methods: A longitudinal birth cohort study was conducted in 1924 children born to women recruited during pregnancy. Maternal diet during pregnancy was assessed by food frequency questionnaire (FFQ). Cohort children were followed up at 5 years by symptom questionnaire and FFQ. Food groups of interest were fruit, vegetables, fruit juice, whole grain products, fish, dairy products and fat spreads. Trends across outcome groups defined by level of food intake are presented. Results: 1253 children participated at 5 years and maternal FFQ data were available for 1212. No consistent associations were found between childhood outcomes and maternal intake of the analysed foods except for apples and fish. Maternal apple intake was beneficially associated with ever wheeze (OR highest vs lowest tertile 0.63, 95% CI 0.42 to 0.95), ever asthma (OR 0.54, 95% CI 0.32 to 0.92) and doctorconfirmed asthma (OR 0.47, 95% CI 0.27 to 0.82) in the children. Maternal fish consumption was beneficially associated with doctor-confirmed eczema (OR >1/week vs never 0.57, 95% CI 0.35 to 0.92). Conclusion: There was no evidence for associations between maternal intake of most foods during pregnancy and asthma, respiratory and allergic outcomes in 5-year-old children, except for apples and fish. Consumption of apples and fish during pregnancy may have a protective effect against the development of childhood asthma and allergic disease.

Results of this study indicate an increased risk of daily versus rare consumption of nut products during pregnancy on childhood asthma outcomes. These findings need to be replicated by other studies before dietary advice can be given to pregnant women.

Summary The prevalence of asthma and allergic diseases has increased dramatically over the past few decades with the highest incidence occurring in children. Most asthma and related atopic disorders have their origins in early life. Thus, it is imperative to understand the early life origins of the disease in order to identify targets for prevention and early intervention. Although atopic diseases have genetic determinants, the increased incidence of these diseases has occurred far too rapidly for genetic changes to explain the increase. This, most likely, results from changes in environmental influences acting on a pre‐existent genetic susceptibility. One of the environmental changes over the last 20–40 years that could have contributed to the recent increase in atopic diseases is diet. Food allergy is often one of the earliest manifestations of atopy, and sensitization to food is a risk factor for the subsequent appearance of respiratory allergy and asthma. However, studies investigating the effects of dietary restrictions on the prevention of allergy have been disappointing. On the other hand, current data suggests that exclusive breastfeeding should be encouraged for at least 4–6 months in infants at both high and low risk of atopy. Increased risk of asthma has also been observed in low birth weight infants, suggesting that under‐nutrition can detrimentally alter foetal development. Epidemiological and immunological studies also suggest that dietary modification or supplementation in the foetal and early life could reduce the development of atopic diseases. The current dietary hypotheses relate to antioxidants, lipids, electrolytes and probiotics. The aims of this report are: (i) to assess the best methods to analyse nutrient intake and nutrient status; (ii) to review the existing epidemiological evidence for an association between dietary intake (nutrients and food) and allergic diseases; and (iii) to define the windows of opportunity for nutritional supplementation to be used as a preventative strategy for asthma and allergy.

Diet may affect the development of asthma. We investigated whether asthma or atopy outcomes at 8 yrs of age were associated with long-term dietary exposure, and whether associations were different for consumption at early or later age.The Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort enrolled 4,146 participants at baseline, who were followed up to 8 yrs of age. Dietary intakes of interest were fruit, vegetables, brown/wholemeal bread, fish, milk, butter and margarine. Associations between food intake at early (2-3 yrs) and later (7-8 yrs) age, and long-term intake, asthma and atopy at 8 yrs of age were calculated by logistic regression.Complete longitudinal dietary data for at least one of the food groups were available for 2,870 children. Fruit consumption at early age was associated with reduced asthma symptoms (OR per 1 consumption day per week increase 0.93, 95% CI 0.85-1.00). Long-term fruit intake was inversely associated with asthma symptoms (OR 0.90, 95% CI 0.82-0.99) and sensitisation to inhaled allergens (OR 0.90, 95% CI 0.82-0.99). We found no consistent associations between diet and outcomes for other foods.This study indicates no consistent effects of increased early or late consumption, or long-term intake of certain foods on asthma and atopy in 8-yr-olds, with a possible exception for fruit.

Studies of the impact of long-term exposure to outdoor air pollution on the prevalence of respiratory symptoms and lung function in children have yielded mixed results, partly related to differences in study design, exposure assessment, confounder selection and data analysis.We assembled respiratory health and exposure data for .45,000 children from comparable crosssectional studies in 12 countries. 11 respiratory symptoms were selected, for which comparable questions were asked. Spirometry was performed in about half of the children. Exposure to air pollution was mainly characterised by annual average concentrations of particulate matter with a 50% cut-off aerodynamic diameter of 10 mm (PM10) measured at fixed sites within the study areas.Positive associations were found between the average PM10 concentration and the prevalence of phlegm (OR per 10 mg?m -3 1.15, 95% CI 1.02-1.30), hay fever (OR 1.20, 95% CI 0.99-1.46), bronchitis (OR 1.08, 95% CI 0.98-1.19), morning cough (OR 1.15, 95% CI 1.02-1.29) and nocturnal cough (OR 1.13, 95% CI 0.98-1.29). There were no associations with diagnosed asthma or asthma symptoms. PM10 was not associated with lung function across all studies combined. Our study adds to the evidence that long-term exposure to outdoor air pollution, characterised by the concentration of PM10, is associated with increased respiratory symptoms.