DOES FRUIT AND VEGETABLE CONSUMPTION IMPACT MENTAL HEALTH? SYSTEMATIC REVIEW AND META-ANALYSES OF PUBLISHED CONTROLLED INTERVENTION STUDIES.

Associations between fruit and vegetable (FV) consumption and mental health are suggested, largely from observational studies. This systematic review aimed to identify and summarize all published controlled intervention studies investigating the effects of FV consumption on mental health in adults. Four academic databases (Medline, PsychInfo, Pubmed, Web of Science) were searched on 16.09.22, over all years, for studies that: used an intervention design; included fruit and/or vegetable consumption; included an appropriate non-FV-consumption control; used a validated measure of mental health; and were conducted in healthy adults or adults with solely a depressive or anxiety-related condition. Study details were tabulated and combined using meta-analyses. Risk of bias was assessed using the domains of the Cochrane Collaboration. Six studies, enrolling 691 healthy adults, and reporting on one or more mental health outcomes were found. Meta-analyses found small and imprecise effects of FV consumption: Psychological Well-being (4 studies, 289 participants) SMD=0.07 (95% confidence intervals (95%CI) -0.17, 0.30), p=0.58, I 2 =0%; Depressive Symptomology (3 studies, 271 participants) SMD=-0.15 (95%CI -0.40, 0.10), p=0.23, I 2 =46%; Anxiety-related Symptomology (4 studies, 298 participants) SMD=-0.15 (95%CI -0.39, 0.08), p=0.20, I 2 =69%. Some benefit for Psychological Well-being was found in change-from-baseline data: SMD=0.28 (95%CI 0.04, 0.52), p=0.02, I 2 =0%). Risk of bias was high in many studies. Limitations include the consideration only of published studies, and stem from the studies found. Given the few, limited studies available and the small size of effects, stronger evidence is needed before recommending FV consumption for mental health.