Plant-based dietary quality and depressive symptoms in Australian vegans and vegetarians: a cross-sectional study.

Megan Frances Lee, Ryan Eather, Talitha Best

Journal: BMJ nutrition, prevention & health 2021;4(2):479-486

PMID: 35028517

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Plain Language Summary

Poor diet and mood disorders are known leading causes of morbidity and mortality. Some studies suggest that plant-based diets are associated with improved mood and mental health. The aim of this study was to explore the association between vegan and vegetarian dietary patterns and depressive symptoms in adults by exploring the overall dietary quality of these patterns. This study is an online cross-sectional study which invited vegan and vegetarian adults aged between 18 and 44 years who live in Australia to complete an online survey through social media platforms. Results show that high plant-based diets quality was associated with decreased risk of depressive symptoms. However, this study also shows that following a plant-based diet does not necessarily mean the individual consumes a ‘healthy’ dietary pattern. Authors conclude that further studies are needed which should focus on the specific quality of vegan and vegetarian diets in relation to depression and mental well-being.

Abstract

Plant-based dietary patterns (vegan and vegetarian) are often considered 'healthy' and have been associated with broad health benefits, including decreased risk of obesity and ill health (cardiovascular disease, blood glucose and type II diabetes). However, the association between plant-based diets and mood disorders such as depression remains largely equivocal. This cross-sectional study of 219 adults aged 18-44 (M=31.22, SD=7.40) explored the associations between an estimate of overall plant-based diet quality and depression in vegans (n=165) and vegetarians (n=54). Overall plant-based diet quality was associated with depressive symptoms in vegans and vegetarians F(1, 215)=13.71, p<0.001 accounting for 6% of the variation in depressive symptoms. For those without depression, higher diet quality was protective against depressive symptoms F(1, 125)=6.49, p=0.012. Conversely, for those with depression no association with diet quality was found F(1, 89)=0.01, p=0.963. These findings suggest that a high-quality plant-based diet may be protective against depressive symptoms in vegans and vegetarians. In line with emerging research between food and mental health, higher-quality dietary patterns are associated with a reduced risk of depressive symptoms. Given the rapidly increasing rate of vegan and vegetarian food products within Australia, understanding the potential mechanisms of effects through which a plant-based diet may influence depressive symptoms is required.

Address: Faculty of Society and Design, Bond University, Robina, Queensland, Australia.; School of Health, Medical and Applied Sciences, NeuroHealth Lab, Appleton Institute, Central Queensland University, Brisbane, Queensland, Australia.

DOI: 10.1136/bmjnph-2021-000332