Eat Yourself Happy
If you are struggling with anxiety or depression – or know someone who is – here’s some good news. Simply changing what you eat can help lift your mood.
“What we put in our mouths influences not just our physical health, but also our mental health,” explains Felice Jacka. “Depression is not just something that happens in the brain. It’s a whole-body disorder and diet is a key predictor for, and influencer of, many of the systems involved including the immune system.
“We now have a very comprehensive consistent body of evidence – across countries, across cultures, across age spans – linking the quality of people’s diets to the risk for the common mental disorders, depression and anxiety.”
Researchers have been charting the surprising links between the gut and the brain. “This nexus is a central part of the human stress response,” Professor Jacka says. “Your gut and its resident microbiota are involved in mediating the stress response in humans. Additionally, 70 per cent of the body’s immune system function is dependent on the gut. These systems are both closely related to depression.”
Professor Jacka, director of the Food & Mood Centre at Deakin University and the author of Brain Changer: Good Mental Health Diet and the children’s book There’s a Zoo in My Poo, has been behind landmark studies including the SMILES Trial, the first intervention study that tested dietary improvement as a treatment for depression.
“We looked at patients with moderate to severe symptoms of clinical depression and we found that dietary improvement had a significant impact on their depression. The degree to which they changed their diet correlated closely with the degree to which their depression improved. That’s been confirmed by more studies since then,” Professor Jacka says.
Advances in technology allow Professor Jacka and her colleagues to map how a change in diet can physically change the brain. In one study, MRI scans revealed that people who have diets high in fruit, vegetables and fish have larger hippocampi, the hippocampus being the region of the brain involved in learning, memory and mood. Several other studies have since confirmed this link.
“We’re all used to hearing that if you eat this or that, one day you might have a heart attack,” Professor Jacka says. “But when you tell people that what you eat today can affect your ability to remember things or how you feel in a short timeframe, that cuts through.”
Professor Jacka became interested in the field through personal experience. “I was studying psychology but, as someone who had experienced anxiety and depression, I quickly realised that I didn’t want to be a counselling psychologist. I became interested in neuroscience and I’d always had a strong interest in food as an underpinning of health, so that was where I started researching.”
While more research is being done into a variety of conditions – “we are extending studies to examine the role of diet in many other psychiatric disorders, including schizophrenia, anorexia and multiple sclerosis” – Professor Jacka says that some basic principles have become clear. Chief among them is the fact that a brain-healthy diet should be based around vegetables, fruit, legumes, wholegrain cereals, nuts and seeds, as well as foods rich in omega-3, such as fish, and monounsaturated fatty acids.
“We’re not saying you need to go out and buy organic,” Professor Jacka says. “A healthy diet is what I would call a peasant diet, with beans, fish and vegetables. You can use dried beans or tinned beans or tinned fish or frozen vegetables.”
Our growing reliance on processed food may be a factor in the apparent rise in mental health disorders. “The big industrialised food industry has a vested interest in keeping people confused about what is healthy,” Professor Jacka says. “People who don’t know how to prepare food will head straight for the most available, most heavily marketed food, which is processed food.”
Until now, much of the messaging around eating healthy foods has been linked to weight issues, something that Professor Jacka would like to see change. “The quality of your diet really matters to overall health, quite apart from body weight,” she says. “Eat better and you see improvements in learning and memory and mood before any changes in weight appear.”
If this article has raised any issues contact: Beyond Blue (beyondblue.org.au 1300 22 46 36) or Lifeline (lifeline.org.au 13 11 14).
Words_ Ute Junker
Photo_ Raul Angel/UnSplash