Posted on 07 June 2019
According to Beyond Blue, 1 in 6 Australians are currently experiencing anxiety or depression or both. That’s over 3 million Australians who are suffering right now. And while causes are known to include stress, loneliness, and isolation, research suggests the link between diet and mental health might also be crucial to understanding anxiety and depression, with the microbiome playing an important role.
First, it’s probably important to define what the hell a microbiome is, so bear with us for a moment. Your microbiome is essentially where all your bodily bacteria live. If we break down the word, micro = small, and biome = living habitat. Google tells us that the microbiome is the combined genetic material of the microorganisms in a particular environment. Basically, it’s the world in which the microbes – bacteria, fungi, protists and viruses – of our bodies live, mostly in our gut. The microbiome’s activity has previously been linked with immunological function, hormonal regulation and many other critical functions but now studies are linking its function to depression and other psychological states. In particular, two types of bacteria – Dialister and Coprococcus – were found to be lacking in those who had suffered from depression1.
So, you might be asking, what have bacteria got to do with mental health? Well, recent research tell us that your microbiome is a direct line of communication between your gut and your brain. According to one study, there is considerable evidence showing that the gut microbiome not only affects digestive, metabolic, and immune functions but also regulates sleep and mental states through the microbiome-gut-brain axis2. So, put simply, if you’re not eating well, your microbiome is telling your brain it’s not happy, essentially making you depressed.
So, when we eat processed and sugary foods, it’s not only your body that suffers. As it turns out, this type of diet can have a severe effect on your mental health too. But, what can we do about this? Deepak Chopra adopts a spiritual line, telling us to approach each meal with joy, to ask ourselves “will this experience of eating this meal be a pleasant one?” And he not only recommends a rainbow diet, one consisting of as much colour through natural and fresh ingredients but also suggests that a meal should consist of six tastes: salty, sweet, sour, bitter, pungent and astringent. This method of satisfying all the tastes allows us to hit all the food groups and nutrients and stops us from craving something else after dinner.
In 2016, a group performed a study called the SMILES trial (Supporting the Modification of lifestyle In Lowered Emotional States) to investigate if a healthy diet could have any benefits on a person suffering from depression and anxiety3. The trial split participants into two groups; one group were given social support while the other dietary support. The dietary group were given personalised dietary advice and nutritional counselling support, including motivational interviewing, goal setting and mindful eating, from a clinical dietitian.
The social support, using the same visit schedule and length as the dietary support, used a manualised ‘befriending’ protocol that consisted of trained personnel discussing neutral topics of interest like sport, news or music, or playing cards and board games, with the intention of keeping the participant engaged and positive.
The primary focus was on increasing diet quality by supporting the consumption of the following 12 key food groups:
- Whole Grains
- Low-Fat and Unsweetened Dairy Foods
- Raw and Unsalted Nuts
- Lean Red Meats
- Olive Oil
They also reduced the intake of ‘extras’ foods, such as sweets, refined cereals, fried food, fast-food, processed meats and sugary drinks to no more than 3 serves per week. Red and white wine consumption beyond 2 standard drinks per day and all other alcohol (e.g. spirits, beer) were included within the ‘extras’ food group.
The results of the SMILES trial indicated that an improvement in diet could indeed be an effective treatment for the management of depression and anxiety. The trial does suggest a larger scale study is needed to confirm the results, however, it appears the benefits of an improved diet lead to a healthy body and indeed, a healthy mind.
A final note, while addressing a poor diet could be of great benefit, if you feel like you’re suffering from depression or anxiety, please talk to someone. Battling these demons can feel like a monumental task, but there is always someone there to talk to. Your mental health is important. Remember, it’s ok to seek out help.
- Valles-Colomer, Mireia et al, ‘The neuroactive potential of the human gut microbiota in quality of life and depression’, Nature Microbiology, 4th February 2019
- Li, Yuanyuan et al, ‘The role of microbiome in insomnia, circadian disturbance and depression,’ Frontiers in Psychiatry, 5th December 2018
- Jacka, Felice et al, ‘A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial)’, BMC Medicine, 30th January 2017
By Andy Browne