Lady eating vegetable-dense soup dish

The impact of dietary changes on symptoms of depression and anxiety [Commentary]

Several Australian researchers recently completed a meta-analysis of the impact of dietary changes on symptoms of depression and anxiety. The original article, “The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomised controlled trials”, can be located here.

It’s also been reported by lifestyle and health writer Sarah Berry in the Fairfax media here.

While the current “mainstream” treatments for depression and anxiety are pharmacological and psychological, this analysis suggests another possible avenue of treatment. The effects of diet on mood have been known for some time; however, the possible impact of dietary modification as a treatment intervention has not been well understood.

A meta-analysis on Randomised Controlled Trials (RCT) can often provide a better understanding of how a treatment works and increased confidence in its application. This meta-analysis ultimately reviewed 16 previously conducted RCTs with nearly 46000 subjects. While dietary interventions did not appear to significantly impact anxiety symptomatology, the effects on depressive symptomatology were marked.

Somewhat unsurprisingly, all the studies pointed to the benefits of reducing the intake of high fat, high sugar “discretionary” (read “junk”) foods and the inclusion of nutrient dense, high fibre foods, such as vegetables. While the benefits for physical health and well-being of such a dietary change are well understood, this meta-analysis represents a significant step forward in considering dietary interventions for mood disorders, in this case specifically depression.

Anyone with clinical experience working with depression will be familiar with the eating patterns which often accompany – a high fat, high sugar, highly processed and poorly planned diet. But it’s always remained unclear to me how much this is a symptom of depression and how much it contributes – likely it’s both and a self-perpetuating vicious cycle is in play for the person with symptoms of depression.

As a Psychologist who spends a lot of time working with clients with depression, I wouldn’t give up the psychotherapeutic interventions I use, and I will continue encouraging my clients to discuss pharmacological treatments with their GPs; however, this analysis adds to my confidence in prescribing dietary lifestyle interventions alongside those treatment avenues.

Whether you’re in medical or allied health practice, it’s as simple as taking some time to ask your patient or client about their diet, discussing what the dietary intervention research is suggesting and exploring with them options to reduce junk food intake and increase whole plant based food intake. Take it a step at a time – replacing one meal on one day, or including one more vegetable or fruit each day is a good place to start.

If you’d like to read more about facilitating health behaviour change, here are some tips.

This commentary has been written for the Australasian Society of Lifestyle Medicine (ASLM) by the documented original author. The views and opinions expressed in this article are solely those of the original author and do not necessarily represent the views and opinions of the ASLM or its Board.

Simon Matthews is a Registered Psychologist, Fellow of the Australasian Society of Lifestyle Medicine, and Member of the Australian Psychological Society.

Original articles from Simon: