Fruit and vegetables and mental health: an emerging research topic with multiple pathways
The World Health Organization (WHO) defines mental health as a “state of mental well-being that enables people to cope with the stresses of life, realize their abilities, learn well and work well, and contribute to their community ».
Mental wellbeing is more than the absence of mental disorder. It implies ‘feeling good’ and ‘functioning well’ and includes aspects such as optimism, happiness, self-esteem, resilience, agency autonomy and good relationships with others (WHO, 2022). Mental disorders are currently considered as a public health concern worldwide, as the number of individuals affected has significantly risen in recent years. Approximately, 970 million people were suffering from mental disorders (GBD 2019 Mental Disorders Collaborators, 2022). Promoting mental health is therefore one of the United Nations’ Sustainable Development Goals (United Nations).
A growing number of studies are exploring the relationships between eating behaviours, movement behaviours and our mental health. These relationships are modulated by multiple potential pathways: targeting core markers of ageing, influencing the composition and diversity of gut microbiota, modifying brain structure, etc. The Global Fruit and Veg Newsletter of this month presents three articles that dive into these links.
The first article explores how different health behaviours or lifestyle factors affect mental health and the core markers of ageing (i.e., telomer length and mitochondrial DNA content). A positive association was reported between a healthy lifestyle and both biological ageing and different dimensions of mental health and well-being, which indicate that a healthy lifestyle contributes to more favourable biological ageing.
The second article summarizes the relationships between gut microbiota and mental disorders and explores the impacts of dietary components on mental health by regulating the gut microbiome. The authors concluded that the composition and abundance of gut microbiota, especially Firmicutes and Bacteroidetes, were associated with several mental disorders, such as anxiety, depression, bipolar disorder, autism spectrum disorder, and schizophrenia. Specific dietary components such as probiotics, prebiotics, dairy products, fruits, vegetables, species could prevent and manage mental disorders by increasing beneficial gut microbiota and reducing harmful ones.
The third article focuses on the effect of fruit and vegetable consumption on brain structure, particularly on grey matter (GM) and white matter (WM) volumes, regional GM volumes and subcortical volumes. According to this work using data from UK Biobank cohort, fruit and vegetable consumption seems to specifically modulate brain volumes. In particular, higher fresh fruit intake is associated with larger grey matter volumes in areas involved in dementia and depression, such as hippocampus.
These three studies confirm that there is a clear association between our health behaviours and brain and mental health via several ways: improving biological ageing, regulating the gut microbiota, and modulating brain structures.
The research of Dr Catherine Féart, PhD in Food Sciences and Nutrition, has focused for many years on the relationship between lifestyle behaviours, especially nutritional habits, and brain ageing, thanks to longitudinal cohorts of older adults. For instance, she observed that a higher adherence to the Mediterranean Diet was associated with slower cognitive decline. Currently, she developed her research on mental health, and already reported the potential benefits of some polyphenols and carotenoids on the prevention of the risk of depressive symptomatology among older adults.