Association of dietary fiber and depression symptom: A systematic review and meta-analysis of observational studies
Somaye Fatahi, Shakiba Shoaei Matin, Mohammad Hassan Sohouli, Mihnea‐Alexandru Găman, Pourya Raee, Beheshteh Olang, Vaani Kathirgamathamby, Heitor O. Santos, Nathália Sernizon Guimarães, Farzad Shidfar
Abstract
A potential relationship between depression and the intake of dietary fiber has been hypothesized in several studies. However, no meta-analysis has been conducted so far to explore the association between these two variables. Hence, we designed the present meta-analysis to elucidate the relationship between the intake of dietary fiber and depression. A comprehensive search was performed using the PubMed/Medline, Scopus, Web of Science and Google Scholar databases to identify any relevant studies published from inception to October 2019. Observational studies (cross-sectional and case-control) were included in the analysis. Pooled analysis from the random-effects model of four case-control studies revealed that the consumption of dietary fiber in patients with depression was significantly lower versus healthy controls (WMD: -1.41 mg/dl, 95 % CI: −2.32, −0.51, P = 0.002). No significant heterogeneity was demonstrated among the analyzed studies (I2 = 4.0 %, P = 0.37). By pooling 5 effect sizes of cross-sectional studies (with a total of 97,023 subjects), we demonstrated that a higher dietary consumption of fiber was associated with significantly lower odds of depression (OR = 0.76; 95 % CI: 0.64, 0.90; P = 0.010), with a low heterogeneity seen among the retrieved studies (I2 = 43.9 %; P = 0.12). An increased intake of total dietary fiber is associated with lower odds of depression. Further studies are needed to evaluate the relationship between the different types of dietary fiber and depression.