By Savannah Meacham in Brisbane

Eat your five serves of fruit and vegetables a day. That’s the message from scientists to help reduce rates of depression, anxiety and stress.

A study by Queensland University of Technology (QUT) has found people who consume less than one serve of vegetables a day, or half a cup or less, have 1.6 times the odds of suffering psychological distress.

That’s compared with people who eat the recommended five or more serves a day.

The study of 45,000 people also found the benefit of vegetables peaks for men around three to four serves, while for women, the more the better.

“Women appear to go on benefiting from vegetables in their diet up to five or more serves per day,” the lead author of the study from QUT’s School of Clinical Sciences, Dr Kerri Gillespie, said.

Women also benefit from consuming fruit each day, which reduces the occurrence of psychological stress, but only up to two servings a day.

“Correlation is never causation, and we have to be careful about that,” said the last author of the study, Professor Selena Bartlett from the School of Clinical Sciences.

“I think, intuitively, most people know that they should be eating more vegetables but rarely do we really think deeply about how it affects your psychological health.”

A second study based on an online survey by QUT of 129 people also uncovered a link between sugary soft drinks and depression.

Having seven or more cups of soft drinks a week increased the odds of depression almost five times.

On the other hand, there may be a relationship between a high-fibre diet and lowered anxiety, with the survey raising questions for further study.

“This can show patterns that we would then look for in a larger sample,” Dr Gillespie said.

The first study has been published in the International Journal of Environmental Research and Public Health and the second in Frontiers in Nutrition.