Mental disorders affect 10% of the world population and represent 30% of non-fatal global burden of disease. Depression is a leading cause of disability worldwide and is projected to rank among the three leading causes of global disease burden by 2030. Depression in later life is associated with increased morbidity and mortality, and decreased physical, cognitive and social functioning.
Evidence suggests a link between diet and mental health, such as depression. Several large cross-sectional studies have shown that greater consumption of fruit and vegetables has been associated with better mental health, including lower odds of depression and psychological distress, in the general population. Higher consumption of fruit and/or vegetables has been associated with lower odds of incident depression in middle-aged Australian women followed over 6 years.
Fruit and vegetable consumption may help reduce the prevalence of psychological distress among middle-aged and older adults. Fruit and vegetables are rich in micronutrients (vitamins and minerals) and phytochemicals that may help reduce oxidative stress and inflammation. Oxidative stress and inflammation can have detrimental effects on mental health. Nutrients can reduce oxidative stress and inflammation. For example, antioxidants such as vitamins C, E and polyphenols may help reduce oxidative stress while magnesium has been associated with lower levels of C reactive protein, a marker of low-grade inflammation. Deficiencies in B vitamins (e.g. vitamin B12 and folic acid) have been associated with depression.
This study found that fruit and vegetables were more protective for women than men, suggesting that women may be more responsive to the health effects of fruit and vegetables.
Nguyen B, Ding D, Mihrshahi S. Fruit and vegetable consumption and psychological distress: cross-sectional and longitudinal analyses based on a large Australian sample. BMJ Open. 2017 Mar 15;7(3):e014201.