Researchers have discovered that raw fruit and vegetables may be better for your mental health than cooked, canned and processed fruit and vegetables.Dr Tamlin Conner, Psychology Senior Lecturer and lead author, said public health campaigns have historically focused on aspects of quantity for the consumption of fruit and vegetables.However, the study published in the journal, ‘Frontiers in Psychology,’ found that for mental health, in particular, it may also be important to consider the way in which produce was prepared and consumed.”Our research has highlighted that the consumption of fruit and vegetables in their ‘unmodified’ state is more strongly associated with better mental health compared to cooked/ canned/processed fruit and vegetables,” said Dr Tamlin Conner.
She believed this could be because the cooking and processing of fruit and vegetables have the potential to diminish nutrient levels.For the study, more than 400 young adults from New Zealand and the United States aged 18 to 25 were surveyed. This age group was chosen as young adults typically have the lowest fruit and vegetable consumption of all age groups and are at high risk for mental health disorders.The group’s typical consumption of raw versus cooked and processed fruits and vegetables were assessed, alongside their negative and positive mental health, and lifestyle and demographic variables that could affect the association between fruit and vegetable intake and mental health (such as exercise, sleep, unhealthy diet, chronic health conditions, socioeconomic status, ethnicity, and gender).” Controlling for the covariates, raw fruit and vegetable consumption predicted lower levels of mental illness symptomology, such as depression, and improved levels of psychological wellbeing including positive mood, life satisfaction and flourishing. These mental health benefits were significantly reduced for cooked, canned, and processed fruits and vegetables,” Dr Conner said.Our analysis showed that increases in the consumption of fruit and vegetables are linked to increases in self-reported mental wellbeing and life satisfaction in data that spans a five-year period, even after accounting for other determinants of mental wellbeing such as physical health, income and consumption of other foods.The benefits of physical activity for mental health are well established. The estimates from our work suggest that adding one portion to your diet per day could be as beneficial to mental wellbeing as going for a walk on an extra seven to eight days a month. One portion is equal to one cup of raw vegetables (the size of a fist), half a cup of cooked vegetables or chopped fruit, or one piece of whole fruit. This result is encouraging as it means that one possible way to improve your mental health could be something as simple as eating an extra piece of fruit every day or having a salad with a meal.It is important to stress that our findings alone cannot reveal a causal link from fruit and vegetable consumption to increased psychological wellbeing. And we can’t rule out so-called ‘substitution effects’. People can only eat so much in a day, so someone who eats more fruits and vegetables might just have less room in their diet for unhealthy foods. Although we accounted for bread and dairy in our study, ideally, future research should track all other foods consumed to rule out alternative explanations.”This research is increasingly vital as lifestyle approaches such as dietary change may provide an accessible, safe, and adjuvant approach to improving mental health,” she continued.
