Does Diet Quality Affect Your Mental Health?

Diet and Mental HealthIt used to be the case that the biggest killers of humans were the infectious diseases such as HIV and malaria. Now, in the 21st Century, non-infectious diseases that are a product of our dietary choices and other lifestyle behaviours (exercise levels and whether or not we smoke) are the main causes of death across the world. Unhealthy lifestyles contribute substantially to conditions such as heart disease; type 2 diabetes; stroke; obesity; and many forms of cancer. The World Health Organisation has told us that these diseases will cost the global community more than US$30 trillion dollars over the next 20 years, and that there are NO countries in the world that can afford these costs. These largely preventable lifestyle-related diseases are already placing a massive burden on our health system and it is only going to get worse. In Australia, poor diet now accounts for more illness than even the tobacco industry.

However, what we haven’t known until relatively recently is that these dietary changes are a problem for mental health as well as physical health. Since the end of 2009, there have been many studies from a multitude of different countries, in age groups ranging from very young children to adults in their 90s, showing that what people eat on a regular basis is related to their risk for depression, anxiety and dementia. Most recently, we have shown that maternal diet is also related to the mental health of offspring.

These studies suggest that two aspects of diet are related to an increased risk for these illnesses: not getting enough healthy food (that is – a variety of different vegetables, fruit, good quality meat and fish, wholegrains and the like) and/or having too much of the unhealthy foods (we all know what these look like – soft drinks, sugary foods, highly processed foods, food chain hamburgers and chicken etc.).

While these findings have important implications, given the huge public health burden of mental disorders, the research is so recent that there are, as yet, no data on the impact of improving diet on the symptoms of individuals who are already suffering from depression. However, we are now conducting the first randomised, controlled trial of dietary improvement as a treatment strategy in major depression.

Diet-depression Randomised Controlled Trial

In this RCT, currently being conducted at both Barwon Health in Geelong and St Vincent’s in Collingwood, Melbourne, participants are randomised to receive either a ‘befriending’ protocol (social support, one-on-one with a practitioner) or a dietary intervention over a three-month period. The dietary intervention comprises weekly, then fortnightly, visits with a clinical dietitian and is designed to facilitate healthy dietary change; participants receive detailed dietary assessments, feedback, education, instructions, menus etc. for the duration of the trial.

We are urgently seeking referrals to the trial. Participants should be: over 18yrs; currently suffering from a major depressive episode (we will confirm); willing to commit to a three-month intervention; with no concurrent psychotic illness, bipolar disorder or personality disorder; and with no unstable medical condition or other factors that may prevent adherence to a dietary regime. Current medication or psychotherapy is not an exclusion criterion; participants can continue with their current treatment as long as it is stable.

Please contact or refer to: or Mel on (03) 4215 3325

For further information for clinicans and researchers, email:

This article is written by A/Prof Felice Jacka. Professor Jacka’s primary goal is to develop a coherent public health message and effective, best-practice strategies for the universal primary prevention of the common mental disorder.

1.O’Neil A, Berk M, Itsiopoulos C, Castle D, Opie, R Pizzinga J, Brazionis L, Hodge A, Mihalopoulos C, Chatterton M, Dean O and Jacka F. A randomised, controlled trial of a dietary intervention for adults with major depression (the SMILES trial): study protocol BMC Psychiatry 2013 doi:10.1186/1471-244X-13-114

2. Jacka FN, Pasco JA, Mykletun A, Williams LJ, Hodge A, O’Reilly SL, Kotowicz MA, Nicholson GC, Berk M. Association of Western and Traditional Diets With Depression and Anxiety in Women American Journal Psychiatry 2010 March;167(3):305-311

3. Jacka FN, Ystrom E, Brantsaeter AL, Karevold E, Roth C, Haugen M, Meltzer HM, Schjolberg S, Berk M. Maternal and Early Postnatal Nutrition and Mental Health of Offspring by Age 5 Years: A Prospective Cohort Study JAACAP Oct;52(10):1038-47 DOI: 10.1016/j.jaac.2013.07.002

4. Berk M, Sarris J, Coulson C, Jacka FN. Lifestyle Management of Depression. Acta Psychiatr Scand 2013: 127 (Suppl. 443): 38–54

5. Jacka FN & Berk M. Depression, diet and exercise MJA Open 2012 Suppl 4: 21-23 doi: 10.5694/mjao12.10508

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