Before you thoughtlessly scoff your next burger and fries, pause to think about how it might affect your mood. Studies led by Deakin University Associate Professor Felice Jacka show that people consuming food and drinks high in sugar and sodium are more likely to develop mental health conditions such as depression. But, by choosing a healthy diet, it may be possible to boost mood and increase your chances of warding off depression.
How are diet and depression linked?
According to Prof. Jacka almost half of all Australians will experience a mental health problem at some stage in their lives. She’s worked with her team at Deakin’s Centre for Innovation in Mental and Physical Health and Clinical Treatment to conduct studies of different countries and age groups.
‘We have brand new data from the ABS telling us that nearly all Australians are failing to meet the basic dietary guidelines, particularly as they relate to the recommended five to six serves of vegetables a day,’ Prof Jacka says. ‘This has large implications for our physical health, but our research now tells us that this is very important for brain and mental health as well.’
In a recent study, Prof. Jacka examined data from MRI scans of approximately 250 older Australians, then studied their diets to see if the quality of their diets was linked to the size of their hippocampus – a region of the brain thought to be central to learning, memory and mood. Those people who had a diet higher in fruit, vegetables and fish had larger hippocampi, while those whose diets were high in processed and takeaway foods had smaller hippocampi. These dietary patterns were also linked to the participants’ risk for depression over time.
'We’re increasingly understanding that the gut is really the driver of health, including mental health, so keeping fibre intake high is very important.'
Associate Professor Felice Jacka,
School of Medicine, Deakin University
Who is at risk?
According to Prof. Jacka, diet is central to brain health as we age and brain power throughout life. She says it’s particularly important for children and adolescents given recent data that shows an overwhelming number of Australians aren’t eating according to the dietary guidelines. In addition, the diets of mothers during pregnancy can impact the mental health of their offspring.
‘We examined more than 23,000 mothers and their children in Norway and found that children of mothers who had unhealthier diets during pregnancy had higher levels of behaviours linked to mental health problems in their first years of life,’ she says.
Eat these things to boost your mood
Through her research, Prof. Jacka has found that mood-boosting foods include: fruit, vegetables, legumes, wholegrain cereals, nuts and seeds and foods with omega-3, such as fish, polyunsaturated fatty acids.
‘Whole (unprocessed) diets higher in plant foods, healthy forms of protein and fats are consistently associated with better mental health outcomes,’ Prof. Jacka explains. That’s because these foods are the foundation of health and contain the many thousands of nutrients needed for the optimal functioning of the body and brain. ‘These diets are also high in fibre, which is essential for gut microbiota. We’re increasingly understanding that the gut is really the driver of health, including mental health, so keeping fibre intake high through the consumption of plant foods is very important.’
Invest in nutrition
There is a misconception that nutritious foods are expensive and therefore rates of poor diets are higher in low socio-economic households, but Prof. Jacka says that her team’s modelling has shown that this is not necessarily the case. However, she says there is a higher concentration of fast food outlets in these locations, which makes unhealthy food choices too easy to make. ‘Big business has made highly processed food products so readily available and heavily marketed that people everywhere have fundamentally changed their diets for the worse,’ she says.
‘Governments must act immediately to limit the availability and marketing of these food products, but also we must relearn the art of smart shopping and home cooking for the sake of our physical and mental health,’ Prof. Jacka cautions. Ultimately, people can choose to improve their well being by modifying their diets without spending a fortune. Fruits, vegetables, grains, beans, tinned fish and inexpensive meats provide a better alternative to take-away.