How effective are dietary interventions for perinatal depression, anxiety?

Dietary interventions, such as polyunsaturated fatty acids (PUFAs) and iron intake, are not useful in reducing perinatal depression, reveals a study. However, supplementation with vitamin D in 1,800 to 3,500 IU per day appears promising.

A systematic review and meta-analysis was carried out to explore the effectiveness of dietary interventions for the treatment of perinatal depression or anxiety. The investigators searched the Medline, Embase, PsycINFO, Cinahl, and Web of Science from inception to 2 November 2022 for studies in English that examined the use of these interventions in a randomized controlled trial.

A total of 4,246 articles had been identified, but only 36 were included; 28 were eligible for meta-analysis. Random-effects meta-analyses were conducted.

PUFAs did not improve symptoms of perinatal depression when compared to control conditions (standardized mean difference [SMD], ‒0.11, 95 percent confidence interval [CI], ‒0.26 to 0.04). These findings persisted when examined during pregnancy or the postpartum period separately and did not change according to the fatty acid (FA) ratio.

Elemental metals such as iron, zinc, and magnesium were also ineffective relative to placebo (SMD, ‒0.42, 95 percent CI, ‒1.05 to 0.21). However, vitamin D produced a small to medium effect size improvement (SMD, ‒0.52, 95 percent CI, ‒0.84 to ‒0.20) in postpartum depression.

Notably, iron intake remains beneficial in women with confirmed iron deficiency.

“Narrative synthesis was performed for studies ineligible for meta-analyses.,” the authors said. “Additional high-quality, large-scale randomized controlled trials are needed to determine the true effectiveness of dietary interventions on perinatal depression and/or anxiety.”