According to a new study, young men who had a bad diet noticed a substantial improvement in their depressive symptoms when they transitioned to a healthy Mediterranean diet.
Depression is a widespread mental health problem that affects about 1 million Australians each year. It is a major risk factor for suicide, which is the largest cause of mortality in young people. The 12-week randomised control experiment was just published in the peer-reviewed American Journal of Clinical Nutrition by experts from the University of Technology Sydney.
The study was the first randomised clinical trial to investigate the influence of a Mediterranean diet on depressive symptoms in young males, according to lead researcher Jessica Bayes, a PhD candidate in the UTS Faculty of Health (aged 18-25).
“We were surprised by how willing the young men were to take on a new diet,” Bayes said. “Those assigned to the Mediterranean diet were able to significantly change their original diets, under the guidance of a nutritionist, over a short time frame.”
“It suggests that medical doctors and psychologists should consider referring depressed young men to a nutritionist or dietitian as an important component of treating clinical depression,” she said.
The research contributes to the developing subject of nutritional psychiatry, which seeks to investigate the impact of specific nutrients, foods, and dietary patterns on mental health. The study’s diet included a variety of colourful vegetables, legumes and wholegrains, oily salmon, olive oil, and raw, unsalted almonds.
“The primary focus was on increasing diet quality with fresh wholefoods while reducing the intake of ‘fast’ foods, sugar and processed red meat,” Bayes said.
“There are lots of reasons why scientifically we think food affects mood. For example, around 90 per cent of serotonin, a chemical that helps us feel happy, is made in our gut by our gut microbes. There is emerging evidence that these microbes can communicate to the brain via the vagus nerve, in what is called the gut-brain axis.
“To have beneficial microbes, we need to feed them fibre, which is found in legumes, fruits and vegetables,” she said.
Approximately 30% of depressed individuals may not react satisfactorily to traditional therapies for major depressive disorder, such as cognitive behaviour therapy and antidepressant drugs.
“Nearly all our participants stayed with the program, and many were keen to continue the diet once the study ended, which shows how effective, tolerable and worthwhile they found the intervention.”
