When we're sitting down to eat a meal, most of us don't think about how food could affect our mental health. But more research is showing the connection between what we eat and depression, and new research has validated this.
Using a first-of-its-kind 'Risk Index for Depression' to assess how different behaviours affect the risk of depression, the research found that our diet is the most important contributor to mental health, followed by other factors like sleep and exercise.
The research, predominantly done through IMPACT SRC at Deakin University in collaboration with Swinburne University, confirms that depression is not caused by one simple factor or event, but rather various factors which, if identified for each young person, could help clinicians recognise the early signs of depression. In other words, the Risk Index for Depression is about prevention.
Considering depression is a global health concern -- with one in six people to experience depression at some point in their life which will affect their wellbeing, personal relationships, work life and productivity -- the Risk Index for Depression shows promise as a tool to add (or remove) direct or indirect risks.
To understand more about the risk determinants for depression, HuffPost Australia spoke to the Risk Index for Depression (RID) developer and Swinburne lecturer in the Department of Statistics, Data Science and Epidemiology, Joanna Dipnall.
"We utilised a large database from the U.S. which has a huge amount of information about people's diet, lifestyle and self-reported medical symptoms," Dipnall said.
"We spent time compartmentalising each of the risk determinants for depression, which include diet, lifestyle, environs, biomarkers and somatic symptoms, and for each of those we put into a probability of depression and built this into a structural model of the RID to see if we could determine an overall risk of depression and isolate the important elements.
"What we found confirms that depression is not a simple condition -- it is complicated and multifaceted. It confirms that diet is one of the most important to asses the risk of depression. Diet has a direct path."
In the research, under each main risk determinant there are predicted probabilities of depression. Lifestyle included sleep, weight and exercise; demographics included gender, rage and age; biomarkers included red cell distribution risk; somatic symptoms included pain, bowels and thyroid; and diet included fruit, vegetable and whole grain intake.
A key finding from the research is that a person is more likely to become depressed if their diet is poor, their lifestyle is erratic and they do not exercise.
"Interestingly, in somatic symptoms (which included symptoms of pain, liver and hearing) what dominated was the bowels. This also ties into diet," Dipnall told HuffPost Australia.
"The team at Deakin University in the Food and Mood Centre are looking even further into this in isolation and have already found dietary fibre being central to gut health. My research is further confirming this."
So, what's comes next?
"This is the first stage. The RID is modular so we want to build on this model to include the important aspects of factors such as 'stressful life event'," Dipnall said.
"It's not yet ready and needs more research, but ultimately the RID is about a predisposition to depression. What we want to do is be able to look at younger people and intervene based on their Risk Index with the best targeted intervention."
Essentially, in the future clinicians may be able to use this tool to work out a young person's predisposition for depression and identify their various individual determinants.
"Adolescents would go to their clinician and work out their Risk Index and where it's most affecting their risk -- is it their diet, lifestyle, stressful event?" Dipnall explained.
"A lot of people talk about depression and say, 'You've got to do this to help your mood', but nobody has really tried to bring it together to say, 'Yes there's diet, yes there's lifestyle, and yes you have these somatic symptoms'."