The Impact of Diet Quality on Mental Health – Prof Felice Jacka

Posted on December 31, 2016

If we are wanting to think about prevention we need to be really thinking about these early time periods

A/Prof Felice Jacka begins this section of her talk with a discussion about common mental health disorders – anxiety and depression. The average age of onset for anxiety is six years old; whereas, the average age of onset for depression is 13 years old.

There is good evidence now that suggests that the prevalence of psychological distress, particularly in young people, is actually increasing. In addition, over a similar time period, there has been a significant increase in obesity rates. The apparent increase in the prevalence of psychiatric distress in young people has tracked with the increase in obesity as well.

Between 25-30% of young people in Australia are overweight or obese and 65% of the adult population.

One of the primary drivers of systemic inflammation is adipose tissue, particularly around the gut.

Two important studies (1 &2) led by A/Prof Jacka  found that for each standard deviation increase in the unhealthy ‘Western’ dietary pattern, there was an increase in the odds ratio for the mood disorders – major depression, dysthymia and bipolar disorder; however, not with anxiety in this particular case (the results were adjusted for age, education, SEIFA (Socioeconomic indexes), PA (Physical activity), smoking, alcohol, energy intake and BMI).

The SUN cohort study (4) looked at the participants’ level of adherence to a Mediterranean-style dietary pattern (which is a very healthy way of eating), and they tracked them for about 4 ½ years, looking for the incidence of depression.

The higher the level of adherence to a Mediterranean style diet, the lower the risk for new depression over that time frame

The Whitehall II cohort study (5) found that higher scores on the Western-type dietary pattern predicted de-novo depression over the 5-year follow-up period and those on a whole foods dietary pattern had a reduced risk; not explained by reverse causality.

The SUN Project (6) which studied the role of dietary fat intake and the risk of depression reached the following conclusion-
A detrimental relationship was found between TFA (trans unsaturated fatty acids) intake and depression risk, whereas weak inverse associations were found for MUFA, PUFA and olive oil. These findings suggest that cardiovascular disease and depression may share some common nutritional determinants related to subtypes of fat intake.
Another study (7) investigating the relationship between fast food and commercial baked goods consumption showed an almost 40% increase of new depression over time.


  1. Jacka, F. N., Pasco, J. A., Mykletun, A., Williams, L. J., Hodge, A. M., O’Reilly, S. L., … & Berk, M. (2010). Association of Western and traditional diets with depression and anxiety in women. American Journal of Psychiatry, 167(3), 305-311.
  2. Jacka, F. N., Pasco, J. A., Mykletun, A., Williams, L. J., Nicholson, G. C., Kotowicz, M. A., & Berk, M. (2011). Diet quality in bipolar disorder in a population-based sample of women. Journal of affective disorders, 129(1), 332-337.
  3. Jacka, F. N., Mykletun, A., Berk, M., Bjelland, I., & Tell, G. S. (2011). The association between habitual diet quality and the common mental disorders in community-dwelling adults: the Hordaland Health study. Psychosomatic medicine, 73(6), 483-490.
  4. Sánchez-Villegas, A., Delgado-Rodríguez, M., Alonso, A., Schlatter, J., Lahortiga, F., Majem, L. S., & Martínez-González, M. A. (2009). Association of the Mediterranean dietary pattern with the incidence of depression: the Seguimiento Universidad de Navarra/University of Navarra follow-up (SUN) cohort. Archives of General Psychiatry, 66(10), 1090-1098.
  5. Akbaraly, T. N., Brunner, E. J., Ferrie, J. E., Marmot, M. G., Kivimaki, M., & Singh-Manoux, A. (2009). Dietary pattern and depressive symptoms in middle age. The British Journal of Psychiatry, 195(5), 408-413.
  6. Sánchez-Villegas, A., Verberne, L., De Irala, J., Ruíz-Canela, M., Toledo, E., Serra-Majem, L., & Martínez-González, M. A. (2011). Dietary fat intake and the risk of depression: the SUN Project. PloS one, 6(1), e16268.
  7. Sánchez-Villegas, A., Toledo, E., de Irala, J., Ruiz-Canela, M., Pla-Vidal, J., & Martínez-González, M. A. (2012). Fast-food and commercial baked goods consumption and the risk of depression. Public health nutrition, 15(03), 424-432.