Can we combat depression and anxiety by changing what we eat? JEHAN CASINADER reports.
Talking to Julia Rucklidge is a bit like opening a filing cabinet in the middle of a cyclone. Information pours out of her at a mile a minute – data, dates and details – and I’m desperately trying to grab it all before it blows away.
Rucklidge, a clinical psychology professor at the University of Canterbury, has spent a decade examining the link between food and mental health. She can’t understand why more people aren’t interested in what she has to say.
“New Zealand has a huge mental health crisis,” Rucklidge says. “At least 20 per cent of our population struggles with a mental health issue each year.
“And yet, when we talk about nutrition, we only focus on our bodies. We recognise the impact of diet on obesity, diabetes, teeth and heart health. But we never talk about how our food affects our brains. Why not?”
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Rucklidge’s question was startling, because it forced me to reflect on my own experience of depression. For a couple of years, I relied on sugar, alcohol, coffee and fast food to give me comfort and take the edge off my distress.
Back then, if someone told me to improve my eating habits, I probably would have slapped them. Most days, it was hard enough to get out of bed and go to work, let alone prepare a salad. The presence of junk food in my life seemed like the least of my problems. It never occurred to me that I was putting trash into my brain.
Was my poor diet contributing to my depression? Should my psychiatrist have asked me what was on my plate? And is it possible that some Kiwis are eating their way into depression and anxiety? On all counts, says Rucklidge, the most probable answer is: “Yes”.
Our ancestors understood that food had the power to heal. Hippocrates, the lauded Greek physician, mused: “Let food be thy medicine, and medicine be thy food”. Māori used plants and fungi to treat all manner of ailments. But our forebears could never have imagined the advent of McDonald’s, Coca-Cola and UberEats.
“In the last hundred years, we’ve had the most radical change to our diet in the whole of human history,” says Rucklidge. “New technology – like food colours, emulsifiers and preservatives – have made food taste amazing and last longer. We’re eating things that humans have never eaten before, and our bodies have had no time to adapt.”
Alongside this food revolution, there has also been a pharmaceutical revolution. Born in Canada, Rucklidge was studying neuroscience in the late 1980s when antidepressants came on to the market.
Prozac, the first antidepressant to be marketed in North America, caused a wave of excitement across the world. Drug companies convinced us that these new pills could relieve mental distress. As a young researcher, Rucklidge was captivated by this discovery.
“As clinicians, we began to focus on pharmaceutical drugs as the main treatment for psychiatric disorders,” she explains. “We put all our research money behind this idea that drugs can change the chemistry of your brain, and bingo – a psychiatric disorder can be cured.
“Unfortunately, what we have learned over the past 30 years is that drugs aren’t the miracle cures we hoped for. Yes, some people benefit from medication, but many people don’t. If drugs were so effective in treating depression and anxiety, we wouldn’t have a mental health crisis right now.”
Rucklidge, who has taught at the University of Canterbury since 2000, became curious about whether our loss of nutrition was causing a rise in mental distress. Could it be, she wondered, that our stomachs were full – but our brains were starving?
“The brain is the hungriest organ,” Rucklidge says. “In order to concentrate, to have a stable mood and to combat anxiety, we need to properly feed the organ that regulates all of our emotions. To function well, our brains need to regularly absorb about 30 different vitamins and minerals.”
For centuries, humans gained those nutrients by eating fresh fruit, vegetables and grains. The reinvention of the Western diet changed that.
“Look in your pantry. So much of our food has been stripped of its vitamins and minerals. Our ancestors didn’t have table sugar. They would have consumed sugar by eating fruit, so they would have also received all the fibre and nutrients that were in that fruit. But these days, much of what we eat has been manipulated.”
Rucklidge says the processing of food is “not necessarily a bad thing”. Freezing vegetables, canning fruit, curing meat and pasteurising milk are all forms of processing, but those products retain nutritional value.
Her beef is with “ultra-processed” food – those perfect, packaged products that have often been robbed of their vitamins and minerals. In 2019, an Auckland University study found that 69 per cent of food in New Zealand supermarkets is “ultra-processed” – packed with additives and refined substances.
She is especially critical of the Government’s five-star rating system for food. The number of stars on a packet is a stronger reflection of what isn’t in the food – like sugar, fat, salt and calories – than its nutritional value.
Even if you eat a mixture of carbohydrates, fats and proteins, your food may consist of “empty calories” – lacking in vitamins and nutrients.
“You could eat a cardboard box, if you want to,” Rucklidge laughs. “It has no sugar, no salt, no fat and no calories. But that doesn’t mean it is nourishing your brain.”
So how do we feed our brains well? I was hoping Rucklidge had a secret list of “superfoods”, but she doesn’t believe in them. Nor is she a fan of fad diets or special rules. Her recipe is simple: eat a wide range of real, whole, unprocessed foods.
“Half of your plate should be fruit and vegetables – a range of colours and varieties. Eat what is in season, to make it cheaper. Use shortcuts, like eating frozen peas or beans that come in a can. These are perfectly fine options. Choose foods that are nutrient-rich. It’s not complicated, but if it feels too tough, start with baby steps.”
Overseas research has shown that for some people, improving their diet is enough to reduce the symptoms of depression and anxiety. But Rucklidge notes that each of us has different genetics. Some people will struggle to absorb the vitamins and minerals their brain needs, even if their diet is perfect.
While a lab test may suggest you have the right amount of zinc in your blood, there’s no way of knowing how well it is being metabolised by your brain.
When dietary changes aren’t enough, there’s another option: nutrient supplements. These pills contain a full array of vitamins and minerals – a kind of “top-up for the brain”. Rucklidge and her team have spent a decade investigating whether supplements can help people to recover from mental distress.
When Christchurch was rocked by a large earthquake in September 2010, Rucklidge saw a rare opportunity to test her theory on locals – those who were already taking part in her research – while they lived through a real-life disaster.
“We discovered that the people who were already taking nutrient pills at the time of the quake were more likely to recover from the stress than people who were not taking the pills. Their brains were more likely to cope with the trauma. They had more resilience. It was amazing.”
After the deadly 6.3-magnitude quake in February 2011, Rucklidge recruited volunteers for a trial. Those who took nutrient pills had a “clinically and statistically significant” reduction in anxiety and an improvement in their mood, compared to those who received other treatments or no treatment.
After the Christchurch mosque shootings in 2019, Rucklidge gave nutrient pills to members of the Muslim community who had been affected. Of those who had probable post-traumatic stress disorder, around 78 per cent had a significant recovery after taking nutrients.
Mirwais Waziri was one of them. You may remember him as the man who stood up during the gunman’s sentencing and told him: “You are the loser, and we are the winners”. Waziri, who was shot in the neck at Al-Noor Mosque, remembers the foggy, chaotic weeks after the shooting.
“I could not sleep at all,” he says. “I was worried that someone was going to come into my house and attack my family. I felt like a zombie. I was getting angry all the time, I couldn’t eat much, I lost weight and I was spending a lot of time alone.
“I started taking the nutrients about two months after the attack. After a week, I was sleeping for six or seven hours a night. My appetite came back. I was happier and more energetic. I’m still not 100 per cent, but I am much better than I was before.”
In another study that is yet to be published, nutrient pills were given to pregnant women who were struggling with their mood.
“During my first two pregnancies, I felt low,” says Vanessa Knowles. “My mind just wouldn’t turn off. I would get frazzled and upset easily, and find it difficult to cope with day-to-day life. By the time my husband got home each night, I was exhausted.”
While expecting her third child, Knowles was accepted into Rucklidge’s blind study and began taking 12 pills a day. They were packed with 30 vitamins and minerals.
“I was a bit sceptical. I didn’t expect my mood to change dramatically. But instead, I found that I had a lot more energy. I could work an eight-hour day, come home, tackle dinner with screaming children next to me, and get everyone into bed. Some days were still hard, but I didn’t get overwhelmed and anxious.”
Rucklidge acknowledges that mental distress can be caused by many environmental factors, including poverty, trauma and stress. But she is convinced that, for some people, vitamins and minerals can relieve the symptoms of mood problems.
“Our research shows that people are in a stronger position to respond to life’s challenges – to be resilient – when their brains are healthy. That means nutrition should be at the centre of our mental health system. Sadly, it is not.”
In 2014, Rucklidge delivered a TEDx talk on nutrition and mental health. The video has been viewed 1.7 million times on YouTube, but TEDx has placed a warning on it, claiming Rucklidge “oversimplified” the research used in her presentation.
“It was really heartbreaking,” she says. “It was like having graffiti sprayed all over my house. I felt ashamed of that talk, even though so many people watched it. Everything in it was fact-checked, and I proved the TEDx people wrong. They couldn’t delete it.”
Rucklidge is a voice in the wilderness. For years, she has been lobbying health officials and MPs, demanding that they take notice of her work. Usually, she is rebuffed and told there is a “lack of evidence” that nutrition influences mental health.
She accepts that some of her studies – like those conducted in the aftermath of disasters – were not perfectly controlled, because she was responding to a real-life event, rather than designing a study in a lab. But Rucklidge believes health officials just aren’t interested in finding alternatives to psychiatric drugs.
“I feel absolutely dismissed. When I’ve applied for grants, I’ve often been turned down. I’ve had problems getting my research through ethics approval. It has been really hard to get the data published in good journals.”
Last month, Rucklidge’s earthquake and terror attack data were published in Experimental Psychology, a peer-reviewed international journal.
“When you look at the entire body of worldwide research, you can’t ignore how important nutrition is,” says Rucklidge. “The fact that our public health leaders continue to ignore it is really frustrating.”
Stuff asked the Ministry of Health whether it supports the use of nutrients in the treatment of mental distress. The ministry wouldn’t give a straight answer, but said it is watching the research “with interest”.
Pharmac funds a handful of vitamins and minerals – like Vitamin C and calcium – that doctors can prescribe individually. But it does not fund any products that provide a full spectrum of nutrients for adults.
Rucklidge cautions people against buying individual nutrient pills from health shops or websites. She recommends consulting a doctor before taking supplements or stopping any other medication. But she also wants GPs and mental health experts to educate themselves about the power of nutrition.
“We need our health professionals to ask their patients about their diets. It should be included in every single assessment. We need to increase the number of dietitians in our mental health clinics. And we need to teach people how to shop and cook better. People know how to microwave, but they don’t know how to cook.”
Despite the setbacks, Rucklidge is optimistic that our approach to mental health will evolve. One day, she hopes Kiwis will find mental health treatments in their fridge – not just in their medicine drawer.
“If people show an interest in nutrition, we can start to change the system. [Prime Minister] Jacinda [Ardern] was able to change the gun laws in just four weeks, remember? Where there’s a will, there’s a way.”