Can What We Eat Affect Our Mental Health?
We have always known that what we eat can have an immediate impact on our mood, but can our diets also impact our mental health a bit further down the track?
The answer, backed up by a rapidly growing body of exciting evidence in the field of nutritional psychiatry, is yes!
In fact, there is evidence to show that a healthy diet can not only help prevent the onset of mental disorders, but also help those with existing mental disorders go into remission. (1)
Considering mental illness is currently the leading cause of disability worldwide, and diet-related disease is the leading cause of premature death in middle- to high-income countries, these findings are of great significance. (2, 3) Importantly, these results also offer some crucial alternatives for treatments to debilitating mental disorders.
The Research
Up until fairly recently, the idea that a healthy diet could improve your mental health was only ever supported by observational studies, so it was impossible to determine any real ‘cause-and-effect’ in mental health status.
But, in 2017, a groundbreaking randomised controlled study, known as The ‘SMILES’ trial, was conducted to assess the potential effect that dietary improvement could have on adults with major depressive disorders. (4)
The SMILES trial
The SMILES trial took 67 adults with clinical depression and divided them into two groups; one which would receive social support, and one which would receive a dietary intervention. After 12 weeks the individuals were assessed again. In the social support group, 8% of participants were in remission from depression, but in the dietary intervention group, a huge 32% of participants were in remission from depression! (4)
Diet used in the SMILES trial
Participants in the dietary intervention group followed a modified Mediterranean diet, known as the ModiMed. Rather than focusing on individual nutrients to support mental health, the emphasis was on following an overall dietary pattern that included a number of servings of twelve key food groups.
Whole grains (5-8 servings per day)
Vegetables (6 servings per day)
Fruit (3 servings per day)
Legumes (3-4 servings per week)
Low-fat and unsweetened dairy foods (2-3 servings per day)
Raw and unsalted nuts (1 serving per day)
Fish (at least 2 servings per week)
Lean red meats (3-4 servings per week)
Chicken (2-3 servings per week)
Eggs (Up to 6 per week)
Extra virgin olive oil (3 tablespoons a day)
‘Extra’ foods (e.g. sweets, refined cereals, fried food, fast-food, processed meats and sugary drinks) (no more than 3 servings per week). Red or white wine beyond 2 standard drinks a day was considered one of the ‘extras’.
Stay Tuned
The world of nutritional psychiatry is only young, but exciting new discoveries on the effect that our diets can have on our brain and mental health are happening all the time! The SMILES trial results are just a taste of important developments in this field, which can offer a more holistic and accessible approach to the treatment of mental illness.
References
1. Jacka FN. Nutritional psychiatry: where to next?. EBioMedicine. 2017 Mar 1;17:24-9.
2. World Health Organization. Depression and other common mental disorders: global health estimates. World Health Organization; 2017.
3. Afshin A, Sur PJ, Fay KA, Cornaby L, Ferrara G, Salama JS, Mullany EC, Abate KH, Abbafati C, Abebe Z, Afarideh M. Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. 2019 May 11;393(10184):1958-72.
4. O’Neil A, Berk M, Itsiopoulos C, Castle D, Opie R, Pizzinga J, Brazionis L, Hodge A, Mihalopoulos C, Chatterton ML, Dean OM. A randomised, controlled trial of a dietary intervention for adults with major depression (the “SMILES” trial): study protocol. BMC psychiatry. 2013 Dec;13(1):1-7.
