The associations between frequency of each vegetable consumption and depressive symptoms in Japanese workers: a cross-sectional study

概要

Background: Vegetable intake is an important part of everyday diet and is related to many positive health outcomes. Some previous studies investigated the association between vegetable consumption and depressive symptoms. However, most of these studies examined the association between total vegetable consumption and depressive symptoms. Few studies investigated the association between different types of vegetable and depressive symptoms, and these studies focused on specific population such as teenagers and elderly people, but not a working population who may be prone to depressive symptoms. Therefore, the present study investigated whether the frequency of consumption of a specific vegetable type was associated with the prevalence of depressive symptoms in Japanese adult workers.

Methods: A cross-sectional study was conducted. The final study participants were 1,724 Japanese adults. The frequency of vegetable consumption and depressive symptoms were evaluated using the brief-type self-administered diet history questionnaire and Zung Self-rating Depression Scale (SDS), respectively. The association between the variables was examined using Poisson regression analysis. Age-stratified analysis was performed, and SDS cut-off values of 45 and 50 were used to perform a sensitivity analysis.

Results: After adjustment for covariates including age, body mass index, sociodemographic and lifestyle-related variables, health condition, C-reactive protein, and other dietary variables, an inverse association was found between tomato product and green leafy vegetable consumption and the prevalence of depressive symptoms among men (P for trend < 0.01), but no significant association was found for other vegetable types. For women, the frequency of consumption of none of the vegetable types was associated with the prevalence of depressive symptoms. The results were confirmed by the age-stratified analysis for both sexes.

Conclusions: This study revealed that not all types of vegetables were associated with the prevalence of depressive symptoms. The frequency of tomato product consumption was inversely associated with the prevalence of depressive symptoms in Japanese male workers. Based on present findings, consumption of tomato products may help alleviate depressive symptoms regardless of differences in dietary culture among males. Further studies are required to confirm these finding to clarify causality. Further studies are required to confirm these findings to clarify causality.