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Daily fruit, vegetable consumption linked with reduced psychological distress

Lower rates of psychological distress were associated with moderate daily intake of fruits and vegetables in middle-aged and older adults, according to research published in BMJ Open.

“There has been considerable interest in the relationship between psychological well-being and lifestyle factors, with growing evidence for a link between mental health and diet,” Binh Nguyen, PhD student at the University of Sydney’s School of Public Health, and colleagues wrote.

To investigate the role of fruit and vegetables in the prevalence and incidence of psychological distress, Nguyen and colleagues performed a cross-sectional, prospective study of 60,404 adults (aged 45 years or older) from Australia using logistic regression models. Participants completed questionnaires on sociodemographic characteristics, personal and medical history, and lifestyle risk factors at baseline between 2006 and 2008 and at follow-up in 2010 (mean, 2.7 years). The researchers used the validated Kessler Psychological Distress Scale (K10) to measure general anxiety and depression at baseline and follow-up. They defined psychological distress as a K10 score of at least 22, indicating high to very high levels of distress. Participants reported their usual fruit and vegetable consumption habits by indicating approximately how many servings of fruit and vegetables they consumed every day. One medium piece or two small pieces of fresh fruit or 1 cup of diced or canned fruit pieces was defined as 1 serving of fruit and 0.5 cup of cooked vegetables or 1 cup of raw vegetables was defined as 1 serving of vegetables.

Psychological distress was reported in 5.6% of participants at baseline. Distress at follow-up was reported by 4% of participants who did not report distress at baseline. A lower prevalence of psychological distress was linked to baseline fruit and vegetable consumption. This association was observed both separately and combined, and even after the researchers adjusted for sociodemographic characteristics and lifestyle risk. A lower incidence of psychological distress was also linked to baseline fruit and vegetable consumption in minimally adjusted models and when considered separately or combined.

Compared with participants who consumed 0 to 1 servings of vegetables per day, those who consumed 3 to 4 servings per day were 12% less likely to experience stress. Furthermore, participants who consumed 5 to 7 servings of vegetables per day were 14% less likely to experience stress than those who consumed 0 to 4 servings per day.

Overall, fruit and vegetable consumption was more protective for women than men, according to the researchers. Women who consumed 3 to 4 daily servings of vegetables, 2 daily servings of fruit and 5 to 7 daily servings of fruits and vegetables combined had an 18%, 16% and 23% lower risk of stress than women who consumed 0 to 1 daily servings, respectively.

Consuming higher levels of fruit and vegetables (more than 7 daily servings) and fruit consumption alone were not significantly associated with a lower incidence of stress, Nguyen and colleagues noted.

“Fruit and vegetable consumption may help reduce the prevalence of psychological distress among middle-aged and older adults,” they concluded. “However, the association between fruit and vegetable consumption and the incidence of psychological distress requires further investigation and possibly, a longer follow-up time.” – by Alaina Tedesco

Disclosure: The researchers report funding from Cardiovascular Research Network of New South Wales.