The effects of increasing fruit and vegetable intake in children with asthma: A randomized controlled trial

Abstract

Background A high fruit and vegetable (F&V) diet reduces asthma exacerbations in adults; this has not been examined in children to date. Objective To investigate the effect of a 6‐month, high F&V diet on the time to first asthma exacerbation in children with asthma, in a parallel‐group, randomized, controlled trial. Methods Children (aged 3–11 years) with asthma, history of exacerbations and usual low F&V intake (≤3 serves/day) were randomized to the intervention (high F&V diet) or control group (usual diet) for 6 months. The primary outcome was time to first exacerbation requiring medical intervention. Secondary outcomes included exacerbation rate, lung function, plasma TNF‐α, CRP, and IL‐6, faecal microbiota and peripheral blood mononuclear cell (PBMC) histone deacetylase (HDAC) activity and G‐protein coupled receptor (GPR) 41/43 and HDAC (1–11) expression. Results 67 children were randomized between September 2015 and July 2018. F&V intake (difference in change (∆): 3.5 serves/day, 95% CI: [2.6, 4.4] p < 0.001) and plasma total carotenoids (∆: 0.44 µg/ml [0.19, 0.70] p = 0.001) increased after 6 months (intervention vs control). Time to first exacerbation (HR: 0.81, 95% CI: [0.38, 1.69], p = 0.569; control vs. intervention) and exacerbation rate (IRR: 0.84, [0.47, 1.49], p = 0.553; control vs. intervention) were similar between groups. In per‐protocol analysis, airway reactance z‐scores increased in the intervention versus control group (X5 ∆: 0.76 [0.04, 1.48] p = 0.038, X20 ∆: 0.93 [0.23, 1.64] p = 0.009) and changes in faecal microbiota were observed though there was no difference between groups in systemic inflammation or molecular mechanisms. In the control group, CRP and HDAC enzyme activity increased, while GPR41 expression decreased. No adverse events attributable to the interventions were observed. Conclusion & Clinical Relevance A high F&V diet did not affect asthma exacerbations over the 6‐month intervention, though warrants further investigation as a strategy for improving lung function and protecting against systemic inflammation in children with asthma.

The Effects of Increasing Fruit and Vegetable Intake in Children with Asthma on the Modulation of Innate Immune Responses

“…The complete study design and methodology have been described previously [ 26 ]. Participants were recruited via attendance to the emergency department or admission to the John Hunter Children’s Hospital, Newcastle, Australia, and Maitland Hospital, Newcastle, Australia, following an asthma exacerbation, from September 2015 to July 2018.…”

“…This study reports secondary findings from an RCT that delivered a 6-month dietary intervention to increase F&V intake in children with asthma [ 26 ]. We have previously demonstrated that high F&V diet for 6 months did not prevent exacerbations, though it was associated with improvements in lung function [ 26 ].…”

“…This study reports secondary findings from an RCT that delivered a 6-month dietary intervention to increase F&V intake in children with asthma [ 26 ]. We have previously demonstrated that high F&V diet for 6 months did not prevent exacerbations, though it was associated with improvements in lung function [ 26 ]. In this study, we aimed to extend our previous findings, hypothesising that a high F&V diet would protect children with asthma from exacerbations via enhancing innate immune responses.…”

Early origins of allergic disease

“…However, other approaches to infant skincare do not seem to impact allergic disease development 5 . We also know that there is no causal association between serum vitamin D levels and risk of rhinitis or allergic sensitization, at least in a European‐ancestry population 6 and that while dietary antioxidants may promote improved lung function and respiratory health, 7 the first randomized controlled trial of increasing fruit and vegetable intake in asthmatic children did not impact asthma exacerbations over a 6‐month period 8 . In this issue of the journal, we publish several articles which make important contributions to our understanding of the early‐life origins of allergic conditions.…”

The association of pure fruit juice, sugar-sweetened beverages and fruit consumption with asthma prevalence in adolescents growing up from 11 to 20 years: The PIAMA birth cohort study

“…From this perspective, pure fruit juice may be more comparable with whole fruit in its association with asthma. Available evidence is weak but supportive for the hypothesis that fruit consumption is associated with lower prevalence of asthma and asthma symptoms ( Berthon et al, 2021 , Hosseini et al, 2017 , Garcia-Larsen et al, 2016 , Nurmatov et al, 2011 ). Pure fruit juice can be both fresh juice and bottled juice from concentrate and never contains added sugars, artificial sweeteners or components as artificial colors and preservatives.…”