In a study, published in the journal Psychosomatic Medicine, researchers from Deakin University and the University of Bergen analysed data collected from over 5700 middle-aged and older adults from western Norway.
“We found that the higher the dietary quality of these men and women, the less likely they were to be depressed,” said Dr Felice Jacka from Deakin University’s Barwon Psychiatric Research Unit based at Barwon Health, who led the study.
“Increased dietary quality was also associated with less anxiety in women, while those people eating more junk and processed foods were more likely to be anxious. Even after taking into account other demographic and lifestyle factors, these findings persisted.”
Dr Jacka said that similar associations have been shown in Australian women, but not before in Norwegians.
“We are starting to see a very consistent pattern here,” she said.
“We have now assessed dietary quality in a number of different ways, in different countries, with different measures of mental health. In each of these studies, the results look very similar. This lends weight to the contention that diet plays a role in depression and anxiety.”
The researchers observed that despite the high disease burden of depression and anxiety, psychiatry lacks an evidence-based message to help people reduce their risk for mental illness.
However, Dr Jacka said this information may contribute to reducing the burden of illness in the community and improve outcomes for people suffering from these illnesses.
“It is important to recognise that the same healthy diets that help reduce risk for heart and other medical diseases may reduce the risk for depression and anxiety,” Dr Jacka said.
For the current study, participants filled in detailed questionnaires regarding their normal diets, as well as completing additional questionnaires regarding their mood symptoms. Diet quality was assessed by determining how much and often the participants ate foods such as vegetables, fruits, wholegrain foods, low fat dairy, fish and non-processed red meats.
Other factors which may be associated with both diet quality and depression, such as income and education, as well as physical activity, smoking, and alcohol consumption, were also taken into account.
Read previous media releases on Dr Jacka’s research:
Active kids less likely to develop depression as adults