Researchers formed the finding by analyzing online survey results about mental health, fruit and vegetable intake and preparation, mental health symptoms, and other factors from 422 people aged 18-25 from the United States and New Zealand.
After controlling for factors such as socioeconomic status, sleep, and physical activity, researchers found consumption of raw fruits and vegetables predicted lower depressive symptoms and higher positive mood, life satisfaction, and flourishing in participants.
Consumption of cooked or canned fruits and vegetables, however, predicted higher positive mood only.
"When tested side-by-side, the consumption of raw fruits and vegetables significantly outperformed more processed forms of fruit and vegetable intake in the prediction of mental health,” wrote lead author Kate Brookie, a PhD student at the University of Otago, Dunedin, New Zealand, and colleagues.
“While we did not test the mechanisms that may explain the stronger link between raw fruit and vegetable intake and mental health, a likely factor is that raw fruits and vegetables deliver a greater amount of nutrients than cooked or canned fruits and vegetables.”
Interventions designed to increase the consumption of raw fruits and vegetables may help improve mental health in young adults, a population at high risk of mental disorders yet typically with diets lower in fruits and vegetables, researchers noted.
“This research is increasingly vital, as lifestyle approaches such as dietary change may provide an accessible, safe, and adjuvant approach to improving mental health,” said coauthor Tamlin Conner, PhD, senior lecturer in psychology.