ObjectiveTo synthesize evidence from fruit and vegetable intervention studies investigating mental and/or cognitive health outcomes in children ≤10 years. Our aim was to understand the efficacy of such interventions in improving measures of cognitive performance or mental health, and to identify successful intervention elements to inform future research. Research MethodsWe conducted a systematic search of Cochrane, Embase, PubMed, and CINAHL databases for articles published before August 2022 (PROSPERO registration: CRD42022356571). A narrative synthesis was conducted according to SWiM (Synthesis without Meta-Analysis) guidelines. ResultsFrom 4686 articles identified, only 7 of the 17 full texts screened were included in the final review. No studies investigated the efficacy of interventions using ‘whole’ fruits or vegetables. Six studies examined the effects of blueberries using drinks made from fresh (1 cup) or freeze-dried (30g) blueberries, and one study evaluated a mulberry powder-based drink. Sample sizes ranged from 14-54, and most studies were acute interventions with outcomes measured in a 2–3-hour window (n=6). Through a narrative synthesis of direction of responses, measures of executive function appeared sensitive to intervention effects in both acute and longer-term settings. Some concerns with risk of bias were evident according to the ROB2 tool, related to incomplete reporting of methodological aspects. ConclusionsThe studies identified through this systematic review could not directly address the planned research question, resulting in a poor certainty of evidence. Future research with whole fruit and vegetable interventions could better inform population health strategies for improved mental and cognitive health outcomes in children.
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