New research has suggested that if you want to boost your mental health, eating raw fruit and vegetables could be more beneficial than cooked, canned and processed options.

Carried out by the University of Otago, New Zealand, the study set out to see if how we ate our fruit and vegetables could be just as important, if not more so, as how many we ate. 

Although many public health campaigns have pushed the idea of aiming for five portions of fruit and vegetables a day in any form, the new findings suggest it could also be important to consider in what way produce was prepared and consumed, especially for mental health benefits.

For the study, the team looked at 422 participants aged 18 to 25 and living in New Zealand and the United States.

They chose to focus on this age group as young adults typically have the lowest consumption of fruit and vegetables and are at a high risk for mental health disorders.

Participants were surveyed on their consumption of raw, cooked, and processed fruits and vegetables, as well as their negative and positive mental health, and lifestyle and demographic factors which could affect mental health such as exercise, sleep, unhealthy diet, chronic health conditions, socioeconomic status, ethnicity, and gender.

The team found that eating raw fruit and vegetables was associated with fewer depressive symptoms, higher positive mood, higher life satisfaction, and higher flourishing, which is a feeling of being engaged in your work and daily life and having a sense of purpose.

These mental health benefits were significantly reduced for cooked, canned, and processed fruits and vegetables, with eating processed fruit and vegetables associated only with a higher positive mood.

Lead author Dr. Tamlin Conner believes raw food could be more beneficial for mental health as cooking and processing fruit and vegetables can diminish nutrient levels.

"This likely limits the delivery of nutrients that are essential for optimal emotional functioning," she explains, adding that, "This research is increasingly vital as lifestyle approaches such as dietary change may provide an accessible, safe, and adjuvant approach to improving mental health."

The top 10 raw foods related to better mental health were carrots, bananas, apples, dark leafy greens such as spinach, grapefruit, lettuce, citrus fruits, fresh berries, cucumber, and kiwifruit.

The results can be found published online in the journal Frontiers in Psychology.