From planetary health diet (PHD) to mental health: Higher PHD index protects against depression among the U.S. population

Abstract

Background

Depression is a growing public health concern, and the modest efficacy of current treatments has led to efforts to identify modifiable risk factors. Many nutritional and dietary patterns are linked to depression. The Planetary Health Diet Index (PHDI) measures adherence to sustainable dietary guidelines by the EAT-Lancet Commission. However, the relationship between PHDI and depression has not been studied. This study evaluates this relationship using data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018.

Methods

Multivariate logistic regression and weighted quantile sum (WQS) regressions examined the relationship between PHDI, single nutrients, and depression. A generalized additive model with a smoothing plot analyzed the dose-response relationship.

Results

Among 30,446 participants, the highest quartile of PHDI was linked to a reduced risk of depression. WQS analyses showed consistent associations (OR = 0.71, 95%CI: 0.66, 0.76), with Vitamin C, Fiber, and Selenium significant factors. The dose-response curve indicated a linear association between PHDI and depression, with higher PHDI associated with lower depression risk.

Conclusions

The results of this study show a strong negative correlation between PHDI and depression.