Efficacy of a Mediterranean diet supplemented with fatty fish in ameliorating inflammation in paediatric asthma: a randomised controlled trial.

BACKGROUND: Childhood asthma is the most common respiratory disorder worldwide, being associated with increased morbidity and a decreased quality of life. Omega-3 fatty acids have anti-inflammatory and immunomodulating properties; however, their efficacy in asthma is controversial. The present study aimed to examine the efficacy of a Mediterranean diet supplemented with a high omega-3 'fatty' fish intake in Greek asthmatic children. METHODS: A single-centred, 6-month, parallel randomised controlled trial compared the consumption of a Mediterranean diet supplemented with two meals of 150 g of cooked fatty fish weekly (intervention) with the usual diet (control) with respect to pulmonary function in children (aged 5-12 years) with mild asthma. Pulmonary function was assessed using spirometry and bronchial inflammation by fractional exhaled nitric oxide analysis. RESULTS: Sixty-four children (52% male, 48% female) successfully completed the trial. Fatty fish intake increased in the intervention group from 17 g day-1 at baseline to 46 g day-1 at 6 months (P < 0.001). In the unadjusted analysis, the effect of the intervention was of borderline significance (P = 0.06, ß = -11.93; 95% confidence interval = -24.32 to 0.46). However, after adjusting for age, sex, body mass index and regular physical activity, a significant effect was observed (P = 0.04, ß = -14.15 ppb; 95% confidence interval = -27.39 to -0.91). No difference was observed for spirometry, asthma control and quality of life scores. CONCLUSIONS: A Mediterranean diet supplemented with two fatty fish meals per week might be a potential strategy for reducing airway inflammation in childhood asthma. Future robust clinical trials are warranted to replicate and corroborate these findings.

The role of fish intake on asthma in children: A meta-analysis of observational studies.

BACKGROUND: The evidence is mixed on the use of long chain Omega-3 fatty acids in the prevention and management of childhood asthma. METHODS: We conducted a systematic search and meta-analysis investigating the role of fish intake, the main dietary source of long chain omega-3 fatty acids, on asthma in children. RESULTS: A total of 1119 publications were identified. Twenty-three studies on fish intake in association with childhood asthma were included in the final review. In 15 of 23 studies, early introduction of fish (6-9 months) and regular consumption (at least once a week) improved asthma symptoms and reduced risk in children 0-14 years as compared to no fish consumption; 6 of 23 showed no effect and 2 of 23 studies suggest adverse effects. Meta-analysis revealed an overall "beneficial effect" for "all fish" intake on "current asthma" [OR: 0.75; 95%CI: 0.60-0.95] and "current wheeze" [OR: 0.62; 95%CI: 0.48-0.80] in children up to 4.5 years old. An overall protective effect of "fatty fish" intake as compared to "no fish" intake in children 8-14 years old was also observed [OR: 0.35; 95%CI: 0.18-0.67]. CONCLUSION: This meta-analysis suggests that introduction of fish early in life (6-9 months) and regular consumption of all fish (at least once a week) reduces asthma and wheeze in children up to 4.5 years old, while fatty fish intake may be beneficial in older children. Future well-designed clinical trials are recommended to confirm the promising findings documented in this literature analysis.