For the study, researchers in New Zealand analysed almost 400 participants' eating habits.
Researchers found people who chose to consume raw food also had improved their mood and had a better outlook on life.
While health campaigns have constantly urged people to incorporate fresh vegetables and fruits to their diet, the team have found that the way it is prepared is more important.
"Our research has highlighted the consumption of fruit and veg in their 'unmodified' state is more strongly associated with better mental health," lead author of the study Dr Tamlin Conner, from the University of Otago, told the Daily Mail.
Adding, "This research is increasingly vital as lifestyle approaches such as dietary change may provide an accessible, safe, and adjuvant approach to improving mental health."
According to the report, these foods are what you need to eat raw and have been proven to be most beneficial.
* Citrus fruits
* Dark leafy greens such as spinach
* Fresh berries