Published in the British Medical Journal Open, the longitudinal study of more than 60,000 Australians aged 45 years and above measured participants fruit and vegetable consumption, lifestyle factors and psychological distress at two time points over four years.
Psychological distress was measured using the Kessler Psychological Distress Scale, a 10-item questionnaire measuring general anxiety and depression. Usual fruit and vegetable consumption was assessed using short validated questions.
The study found people who ate three to four daily servings of vegetables had a 12% lower risk of stress than those who ate none to one servings a day.
Furthermore, people who ate five to seven daily servings of fruit and vegetables had a 14% lower risk of stress than those who ate none to four servings daily.
Crucially, the study found that fruit and vegetables were more protective for women than men.
“This study is among the first to report associations between fruit and vegetable consumption and psychological well-being separately for men and women,” said the study.
“When considered separately in each sex, the association of fruit and vegetable consumption with either the prevalence or incidence of psychological distress was stronger in women, with no clear associations with the incidence of psychological distress in men.”
“It is possible that there may be a true physiological difference between men and women, although a mechanism that could explain this difference remains unclear, or perhaps women more accurately report consumption of fruit and vegetables than men."
Fruit consumption alone
Women who ate three to four daily servings of vegetables had an 18% lower risk of stress than women who ate none to one servings daily, while women who ate five to seven daily servings had a 23% lower risk of stress than women who ate none to one servings.
The study also found that fruit consumption alone had no significant association with a lower incidence of stress, while there was no significant association between higher intake of both fruit and vegetables (greater than seven daily servings) and stress.
“This study shows that moderate daily fruit and vegetable consumption is associated with lower rates of psychological stress,” said Dr Melody Ding of the University of Sydney’s School of Public Health.
“It also reveals that moderate daily vegetable intake alone is linked to a lower incidence of psychological stress. Moderate fruit intake alone appears to confer no significant benefit on people’s psychological stress.”
These new findings are consistent with numerous cross sectional and longitudinal studies showing that fruit and vegetables, together and separately, are linked with a lower risk of depression and higher levels of well-being assessed by several measures of mental health.
This research was based on data from the Sax Institute’s 45 and Up Study.
Source: BMJ Open
“Fruit and vegetable consumption and psychological distress: cross-sectional and longitudinal analyses based on a large Australian sample”.
Authors: Binh Nguyen, et al.