• “We have confirmed a relationship between the quality of people’s diets and their risk for depression and anxiety disorders.” (AAP)
The proof is in the (healthy) pudding: what we eat affects our mental health, perhaps even more than we realise.
By
Megan Blandford

2 Feb 2017 - 12:10 PM  UPDATED 2 Feb 2017 - 12:11 PM

In a world-first study, researchers from Victoria’ Deakin University have shown that improvements in diet quality can treat cases of major depression.

The new study, released this week, proves a distinct link between the food we eat and our mental wellness, and finally clarifies the mystery around whether our diet and gut health influences our mood.

“This was the first randomised controlled trial to directly test whether improving diet quality can actually treat clinical depression," says Professor Felice Jacka, Director of Deakin’s Food and Mood Centre.

“...We have confirmed a relationship between the quality of people’s diets and their risk for depression and anxiety disorders." 

The research, published in the international journal BMC Medicine, shows that study participants who made improvements to their diet experienced a reduction in their depressive symptoms.

“We have confirmed a relationship between the quality of people’s diets and their risk for depression and anxiety disorders." 

The 12-week study split participants – who all had depression – into two groups: 25 received social support (with formalised conversation and activities that engaged participants), while 31 people changed their diets. Those in the diet support group were given personalised dietary advice and counselling from an Accredited Practising Dietitian.

The results were surprising: one-third of those in the dietary support group met the criteria for remission of major depression, compared to just eight per cent of those in the social support group. 

“There’s a very strong relationship between physical and mental health,” says Professor Jacka, adding that many mental and physical illnesses (including cardiovascular disease, diabetes and obesity) have the same underlying factors.

“It’s about the immune system and likely the gut microbiota … and diet is the most important factor influencing the health of the gut.”

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Good health doesn’t discriminate

The link between diet and mental health is true for people of all ages, the study states – from babies in utero who are affected by their mother’s diet, through to adolescents and into adulthood.

This fact also holds true for people across all cultures, with no differences in diet outcomes according to background.

“In any country – whether they have a Mediterranean, Norwegian, Japanese, American or Australian diet – there’s a spectrum of diet quality,” says Professor Jacka.

“We see again and again, in every country where these studies are done, that this association (between a healthy diet and mental health) exists.”

However, she says, what’s most important to mental wellbeing is that people with mental health issues receive intervention and support. The study suggests the possibility of making dietitian support available to those experiencing depression.

“It’s about the immune system and likely the gut microbiota … and diet is the most important factor influencing the health of the gut.”

The diet that’s good for mental health

Every country and culture has a different idea of what makes a healthy diet. However, according to Professor Jacka, there are a couple of common dos and don’ts.

  • Do eat whole foods. Eat more plant foods, whole grains and lean proteins for better mental health.
  • Don’t eat too much junk. The more processed food and sugary products you eat, the higher your risk of depression.

Interestingly, this research has revealed that both of those dos and don’ts work together to affect your depression risk.

“Not eating enough good food is a problem, even if you’re not having much junk food,” says Professor Jacka, “and having a lot of junk food is a problem, even if you’re also eating lots of good food.”

And, you may be asking, what is the diet that’s turning depression around? Well, it’s nothing fancy: participants in the study were put on a diet based on the Australian Dietary guidelines.

These guidelines advocate for a varied whole foods diet.

“If you’re depressed and you improve your diet, you should get a benefit to your depression,” says Professor Jacka.

Need one place to start? Eat more vegetables

If you need one place to start making dietary changes for your mental health, it should be vegetables, says Natasha Meerding, Accredited Practising Dietitian and Spokesperson for the Dietitians Association of Australia.

Meerding offers these ideas for getting more veggies into your day:

  • Think about new and creative ways to eat vegetables, to keep yourself interested
  • Aim to have plenty of vegetables in your fridge: if they’re on hand, you’re more likely to eat them
  • Tinned and frozen varieties also offer valuable nutrients and can be convenient alternatives to fresh vegetables
  • Advocate for your workplace to adopt healthy catering policies for training and meetings
  • If you have time, do a big cook on your days off and freeze extra portions of dishes packed full of vegetables

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