The latest science is proving that a healthy diet isn’t only better for you, it’s a mood booster, too. But even the researchers are surprised with the results…
Next time you’re feeling low and you’re certain that reuniting with your favourite tub of Ben & Jerry’s is the answer to your problems, pause and think about this: while that chocolate fudge brownie ice-cream may give you momentary (although delicious) relief in the form of a dopamine hit, there’s a better mood-boosting option. It’s one that has lasting effects and has been proven to decrease depressive symptoms and even anxiety. It can work quickly, too. And it all comes down to what you’re putting on your plate every day.
Intrigued by the way your diet can affect your mental health? So is Professor Felice Jacka, director of the Food and Mood Centre at Deakin University. Her first study found that women who consumed a diet of mostly vegetables, fruit, meat, fish and wholegrain foods were 35 per cent less likely to experience major depression and 32 per cent less likely to experience anxiety disorders than women who consumed a typical Western diet (think processed or fried foods, refined grains, sugary products and alcohol).
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Since then, she’s carried out extensive research on the links between food and mood, but her most well-known finding to date comes from the 2017 SMILES trial.
“It was the first clinical trial to say: ‘If we take people who have moderate to severe clinical depression and we help them to improve their diet, will that improve their depression?’ And we found that it did,” she explains.
The results showed that the group who followed a modified Mediterranean diet for three months had reduced their depressive symptoms to the point where one-third met the criteria for remission compared to only eight per cent of the group that made no changes to their diets but were given social support. “The size of the difference [between the two groups] was really remarkable to me — and unexpected,” Prof Jacka says.
The gut-mind connection
One of the major keys to understanding the food-mood link is in the gut microbiome — the rainforest-like ecosystem in your gastrointestinal tract where good and bad bacteria reside. Research into this area is still quite new, but many studies show a link between the amount and diversity (or lack thereof) of certain bacteria and depression.
A 2019 Belgian study found that people who had been diagnosed with depression were low in two bacteria — coprococcus and dialister. Interestingly, these were found in abundance in people who reported a high quality of life.
“The thing is, researchers don’t really know how the whole journey happens from the stomach to brain,” explains dietitian Anika Rouf, from The University of Sydney’s Charles Perkins Centre. “We know that trillions of microorganisms, the bacteria that live in your gut, help this process of converting tryptophan to serotonin, [but] we don’t actually have a full understanding of the whole process yet.”
She says one of the reasons for the excitement surrounding gut health is that 95 per cent of happy-hormone serotonin is produced in this area. But while the ‘how’ is still being discovered, they do know that people can modify the make-up of their microbiome through food. Prof Jacka says not only is it very empowering, but these changes to your mood also happen very quickly.
“If we think about the way in which diet may affect mental and brain health, one of the primary things we focus on is the gut microbiota,” Prof Jacka says. “The food that you eat has a very pronounced impact on the function of the gut microbiota in a very short space of time, potentially within hours.”
Keeping it fresh
It shouldn’t come as a surprise that the foods that are best for mental health are the same ones that are great for overall health.
And, sorry to break it to you, but “there’s no one magic pill, no [singular] superfood for mental health”, says Rouf. There’s no trendy diet, either. “It’s just important to eat a balanced diet that has quite a bit of variety.”
And ‘variety’ doesn’t mean rotating through different flavours of Ben & Jerry’s. Save it for an occasional treat as, Prof Jacka says, “ultra-processed foods have a negative impact on the brain and on the gut”.
Dietitian Jessica Spendlove, from Health & Performance Collective, says: “Foods that have been shown to help improve mood include plant-based foods, such as legumes, vegetables, fruit, nuts and seeds. They’re high in antioxidants and fibre, as well as B vitamins, which your body uses for energy production.”
She says it helps to focus on fresh, seasonal produce, too. “These contain higher amounts of the nutrients required by the body, due to longer times left on the vine or root system and less transport time to your plate.”
Chloe McLeod, also an H&P Collective dietitian, adds: “Another food that has been shown to improve mood is omega-3 fatty acids in fish such as salmon. These fatty acids assist with serotonin release, which increases its efficiency in the body. Wholegrains, such as oats, brown rice, barley or buckwheat contain an amino acid called tryptophan, which the body uses to produce serotonin.” The latter is why cutting out whole food groups like carbs, isn’t great for your mood, either.
If you haven’t yet embraced fermented foods — like kimchi, kombucha and yoghurt — now is the time. “When something is fermented by bacteria it produces metabolites, and these are really important in the way they influence your immune function and your health,” Prof Jacka explains.
Small amounts of red meat — three palm-sized serves a week — are associated with good mental health, too. Prof Jacka advises those on a plant-based diet to make sure you’re getting enough zinc, iron, protein and B group vitamins. “You have to be careful not to miss out on those important nutrients.”
Like all things, the best way to know if eating for your mental health works for you is to experience it yourself. “Keep a food and mood journal,” suggests Rouf. This entails writing down what you eat and how you feel afterwards. Over time, you’ll hopefully be able to notice the links.
“I think that self-reflection can definitely help people see how the food they’re eating is making a difference in their life.”
If you or someone you know is struggling with mental health, contact Beyond Blue on 1300 22 4636 or Lifeline on 13 11 14.