There is not much to mediate [yet] when it comes to diet and depression

Association between healthy eating and depression symptoms among Chinese older adults: A cross-sectional study based on the Chinese Longitudinal Healthy Longevity survey

Introduction

This study aimed to assess the relationship between the healthy eating index (HEI) and depression symptoms in an older adult population using the Chinese Longevity Health Survey.

Methods

The HEI was constructed based on the frequency of intake of 13 dietary variables, with higher scores indicating better diet quality. Depression symptoms was assessed by the Center for Epidemiologic Studies Depression-10 scale. We used multivariate binary logistic regression to explore the association between the HEI and depression symptoms and reported as odds ratio (OR) and 95 % confidence interval (95 % CI).

Results

A total of 12,078 older adults were included. The average HEI for this group of older adults was 26.4 ± 7.1. After adjusting for covariates, compared with participants in the lowest quartile of a healthy eating index, those in the second to the fourth quartile group had a 0.93- (95 % CI: 0.83 to 1.03), 0.84- (95 % CI: 0.75 to 0.95) and 0.69- (95 % CI: 0.62 to 0.77) fold risk of depression symptoms, respectively. Restricted cubic spline curves showed that the risk of depression symptoms decreased with increasing HEI, especially above 26, and for each unit increase in the HEI, the risk of depression symptoms in older adults decreased by 3 % (OR = 0.97; 95 % CI: 0.96 to 0.99).

Conclusions

This study found an association between higher levels of the HEI and reduced risk of depression symptoms in older Chinese adults. This result emphasizes the need to focus on dietary diversity in older adults to promote healthy aging.

Polyphenols as novel interventions for depression: exploring the efficacy, mechanisms of action, and implications for future research

Numerous animal and human studies have assessed the relationship between polyphenols and outcomes related to depression. However, no comprehensive synthesis of the main findings has been conducted. The aim of this manuscript was to systematically review the available evidence from animal and human studies on the association and the effects of dietary polyphenols on depression and provide recommendations for future research. We based our review on 163 preclinical animal, 16 observational and 44 intervention articles assessing the relationship between polyphenols and outcomes related to depression. Most animal studies demonstrated that exposure to polyphenols alleviated behaviours reported to be associated with depression. However, human studies are less clear, with some studies reporting and inverse relationship between the intake of some polyphenols, and polyphenol rich foods and depression risk and symptoms, while others reporting no association or effect. Hence, while there has been extensive research conducted in animals and there is some supporting evidence in humans, further human studies are required, particularly in younger and clinical populations.