Mood food: diet and your mental health

by Carroll Du Chateau / 09 January, 2013
Some doctors are selling micronutrient supplements, claiming what you eat has an important influence on your mental health, but others remain sceptical.
In our TV-dinner, instant-noodle, cereal-bar-for-breakfast world, blaming diet for a plethora of health problems seems rather too convenient. Feeling bloated? Then give up dairy. Tired all the time? Quit those sugar binges. Down in the dumps? Have we got a supplement for you …West Auckland GP Dr William Ferguson doesn’t believe in quick fixes. And he insists he’s no peddler of snake oil. But after almost three decades of dealing with patients with all kinds of health problems, he would simply like people – including those with mental health issues – to take more notice of their diet.

Ferguson, whose practice is in Kumeu, has been researching mental health for 10 years and is convinced that a major contributor to mental health problems is the effect of the modern Western diet on the brain. His beliefs are controversial, but are supported by some academics and other doctors who are also exploring whether diet helps explain why many people are suffering from an array of problems, from mood disorders to serious psychosis.

“The research now appears to say that, at a population level, we can eat ourselves into a propensity for depression and anxiety,” he says. “However, no one can say yet that we can eat our way out of them.”

A 2006 Ministry of Health survey suggests about 47% of New Zealanders will suffer mental health or addiction problems during their lives. And the World Health Organisation predicts that by 2020, depression will be the second most common illness in the world.

“Depression and anxiety are not really a diagnosis. Underlying them is a complex array of genetic and biochemical patterns and functions, and especially so, it seems, when the illness is lifelong and runs in the family,” says Ferguson.

“What this means is that a one-shot approach, be it by medication, psychological counselling, dietary change or nutritional supplementation, will only ever successfully treat some of the people some of the time. That’s why it’s especially important to sort out people’s nutritional condition, especially those with drug-and alcohol-related illness.”

Ferguson, the 2007 ProCare GP of the year, has had to close his practice to new patients because he doesn’t have time to look after more. Formerly a GP obstetrician, he became interested in the biochemistry of mental illness when he observed the chaos caused by post-natal depression (PND). “There was nothing useful, from a psychosocial perspective, to predict who’s going to get PND and who’s not,” he says.

He also realised that the high incidence of relationship break-ups during the first post-natal year wasn’t necessarily because the woman’s partner was being cruel, unhelpful or hurtful. “It was the other way round. It was the mother’s post-natal depression that was causing all the problems. Then I worked it out: ‘Hang on, this illness is more about biochemistry than psychology.’”
Dr William Ferguson.

Dr William Ferguson.


Despite all the research into mental health, our knowledge of the science behind it is still “minuscule”, he says. “I keep seeing people with a lifetime of not getting fully well despite state-of-the-art medication and psychological treatments. The annoying thing is it’s not just their mental health that’s not doing well – their entire health suffers.”

He started researching functional medicine and biochemistry through the Australasian College of Nutritional and Environmental Medicine. He also used Chicago’s Walsh Research Institute, which, he says, “busted open” the use of diet and biomedical supplements to treat mental health conditions including depression, anorexia nervosa, attention deficit-hyperactivity disorder (ADHD), autism and schizophrenia.

As he explains, not only do we all have a unique set of genes but our genes are uniquely programmed to express themselves. In the brain especially, they need a complex and rich supply of vitamins, minerals, amino acids and other nutrients to keep the system running smoothly.

As well as prescribing drugs and referring patients to clinical psychologists, he often uses supplements. “Methionine, which is often given in the form of a mixture called s-adenosyl methionine (SAMe), and folic acid in its various forms, are very influential over brain chemistry,” he says. “Some people have lifelong imbalances. Giving exactly the right supplementation of these nutrients is key.”

When he started, it would take Ferguson about four hours to analyse a new patient’s psychological history, blood tests and urine samples to work out the combination of supplements needed to rebalance their brain chemistry. “Now I have a better feel for who needs what, it’s quicker.”

The results were transformational. Ferguson still remembers his first patient – a woman who had severe treatment-resistant depression with psychotic features. “After three months, her father rang up and said: ‘Thank you for giving us back our daughter. We felt we hadn’t seen her for 20 years.’”

Dr Shaun Holt, author of Depression: Natural Remedies That Really Work, is also enthusiastic about using SAMe to treat depression. “There’s a big section about SAMe in my book,” he says. “It’s one of the ones I recommend. “The conclusion seems to be it’s very, very safe and effective – but no one, either doctors or patients, has heard of it. It’s the one that’s really safe but we’re not using it enough.”

Holt, with his background as a pharmacist, doctor and position as professor of medicine at Victoria University, is well qualified to talk. One of his courses at Victoria deals with evidence-based natural remedies – “that is, only those ones for which there’s good, sound evidence”. His evidence for SAMe includes a meta-analysis of seven double-blind trials, which shows SAMe is dramatically more effective than a placebo in alleviating depression: 74% compared with 5%.

“I’m pushing the message about complementary therapies. Most patients prefer a natural remedy. [Also] coming off antidepressants can be tricky. It’s not the same as an addict, but they do work on brain chemicals. If you stop, your serotonin levels plummet and you feel awful.”


In the east of Auckland, psychiatrist David Codyre is also familiar with the challenges of depression. Codyre graduated from the University of Auckland School of Medicine with Ferguson, but specialised in mental health. Ten years ago he joined ProCare, which is New Zealand’s biggest primary healthcare group, leading its mental health services. Then he moved to East Tamaki Healthcare.

East Tamaki is where he is needed, he says. Although one in three people in the area has an issue with alcohol, drugs or depression, only a small percentage seek help. Men, in particular, are more likely to say they’re stressed, rather than depressed, says Codyre. Despite public campaigns led by the likes of John Kirwan, many men still believe a stigma is associated with such issues.

David Codyre David Codyre says men, in particular, are more likely to say they’re stressed, rather than depressed, photo David White.

Codyre is convinced mental health is a primary care issue. He helps train doctors and nurses to recognise mental health problems, giving them the tools to detect mental illness, effectively intervene and make sure patients get access to the right help early. “A multinational study comparing the best diet with the worst diet showed the depression risk for those eating a diet high in fatty and processed foods is double that of those eating healthily,” he says.

One study in particular, Te Rau Hinengaro New Zealand Mental Health Epidemiology Study, has some disturbing statistics: Pasifika people who came here aged 18 or over have the lowest risk of depression; those born in New Zealand have the highest risk.

“I can’t believe the research has attracted so little comment,” says Codyre. “Clearly the culture and other factors are in there, but the diet factor can’t be ignored.” He puts the excellent mental health of Pacific people growing up in their home country down, in part, to seafood. “Pacific people have a diet rich in unprocessed food, seafood, fish oil and omega-3. Here, fish is so expensive they eat much less and fill up on cheap processed food.”

He also blames stale, badly stored and badly grown crops. Modern agricultural practices deplete soil, he claims, resulting in food that is not rich enough in vitamins and minerals essential for brain health. To make serotonin, for example, the body needs zinc. “One Australian experiment uncovered oranges containing no vitamin C at all.” Depression, he believes, is caused by many factors. “It’s partly about your psychology – your ability to cope – partly how your environment influences gene expression, partly diet, partly lifestyle. We have huge biochemical vulnerability.”

Then there’s poor parenting and attachment experiences. “Many children live in a chaotic, unstable environment, experience abuse and maltreatment and never learn how to care for themselves as kids. So many describe their childhood to me as making Once Were Warriors look like a picnic.”

Codyre’s success with patients is encouraging. First comes diet, then micronutrients, then supplements. “If you can recognise people’s individual biochemical deficits and give them access to the right food, right medication and right therapies, they tend to improve.”


Many psychiatrists regard such treatment as alternative at best. The reason that so many people take drugs for mental health issues is because they work, they say. Just last month, New Scientist reported the development of a new drug that researchers believe could lift depression within hours, instead of the months it can take currently.

Rob Kydd, professor of psychology at Auckland Medical School, is more equivocal than some. “This is not my area of expertise, but there’s some evidence – though not established – that some oils and supplements including omega-3 fatty acid and folate have an effect, especially in older people,” he says.

He has read a “reasonably good recent study” examining the use of SAMe as a supplementary treatment for people who have not responded fully to standard SSRI antidepressants (such as Prozac and citalopram). “Given that treatment resistance is quite a problem, this is an interesting study. There are a number of other smaller but suggestive studies. The consensus is this is an area that’s showing some promise but needs further exploration – that is, bigger trials.”

The Prime Minister’s chief science adviser, Sir Peter Gluckman, is sceptical. “I have no knowledge of any scientific evidence that is robust with respect to micronutrients and other nutritional interventions in depression,” he says. He warns that the field is “awash with pseudo-claims and pseudo-science”.

The lack of high-quality empirical evidence is the “simple and obvious reason” most of the medical profession would not use such approaches, says Gluckman. “Modern medicine is generally expected to be based on scientific evidence – certainly in terms of treatment modalities.”


GPs selling supplements to their patients have rung alarm bells in the past, particularly those involved in multilevel marketing schemes such as Neo-Life, Nutriway and Mannatech. Concerns have been raised about GPs who persuaded patients to spend large sums on unproven treatments, then pocketed commissions.

The New Zealand Medical Association’s code of ethics doesn’t prohibit the practice but notes that doctors “should not allow their standing as medical practitioners to be used inappropriately in the endorsement of commercial products”. The Medical Council also requires doctors to be upfront in any financial dealings with patients. Ferguson says he sells supplements to his patients at cost and is not part of any multilevel marketing scheme. “We provide the supplements ourselves because of quality issues,” he says. “We import them from whoever has the best deal and the highest quality.”

 Photo Jordi Elias

Some of Ferguson’s patients simply can’t afford to pay. The way general practice is structured, the only way to make money is to give patients a prescription for Prozac and send them out the door, he says. “What we’d really love to see is mental health supplements subsidised like drugs and that people like Winz could support the work we do.”

Ferguson blames the lack of clinical studies into diet and depression on limited funding – especially from pharmaceutical companies, which have nothing to gain from such research – and treatment trends. Large randomised controlled trials also tend to underestimate the efficacy of individualised treatments, he believes.

Vania Miteva, a Bulgarian-born, New Zealand-educated clinical psychologist, believes solid research into diet and depression was ignored once the first drugs that worked on depression appeared “and quickly became the preferred, modern, treatment. “Although most of my work is in counselling, helping people take charge of their lives, I also believe the right diet plus bio-nutrients and supplements can have a quantifiable impact on mental health.” She quotes a 2007 review from the University of Calgary that examined and assessed all published work on the impact of nutrition on mental health and mood between the 1950s and now. “And they all show positive effect.”

Julia Rucklidge, an associate professor of psychology at the University of Canterbury, can also cite international research suggesting that the Western diet increases the risk of developing depression, anxiety and ADHD. She is doing her own formal investigation into the
impact of micronutrients on the brain health of children and adults suffering from those three conditions.

“Until now it’s been too easy to write off the effects of supplements as ‘the placebo effect’,” she says. But even her trial is not specific enough to satisfy her clinical goals. “No way can we say which specific nutrient is making the difference in a specific person. It’s a shotgun approach and as a scientist it makes me cringe. But the practitioner in me says, ‘Does it really matter as long as people are getting better?’”


Given that mental illness tends to run in families, psychiatrists and scientists had high hopes that the mapping of the human genome, which was completed in 2003, would provide genetic answers. Unfortunately, says Ferguson, the genetic markers for mental illness were disappointingly evasive.

However, scientists have since recognised the significance of epigenetics – the layer of markers that clip onto individual genes. As Ferguson says with genuine excitement: “It’s like a layer of software that sits on top of the genetic hardware. And that software regulates gene expression. In other words, it can turn genes up and down and, in extreme cases, turn them on and off.”

Scientists used to believe a single gene was coded for the formation of a single protein. But it is now believed that altering the epigenetic regulation of an individual gene can code about 30,000 different proteins. “It’s hard to think of a disease for which those findings may not be important,” says Ferguson. In January 2010, Nature magazine predicted that this is likely to be “the decade for psychiatric disorders”. The magazine noted that many psychiatrists’ knowledge of contemporary biology was “shallow at best”, and predicted that as biological insights develop, “the crudity of current psychiatric diagnoses will become all too clear”.

Ferguson’s belief is that environmental influences such as stress, nutritional deficiency and toxin exposure may all contribute to the regulation of gene expression through epigenetic mechanisms. “Somewhere therein lies the key to the dramatic increase in cases of depression, which are becoming epidemic.”

What’s more, he believes these regulators appear to programme our health outcomes when we’re still in the womb and in our first year of life. “I like to tell women to pay extreme attention to the quality of their diet in pregnancy: get all the plastic out of their food chain, go off the oral contraceptive pill well before they want to get pregnant. An awful lot of things come back to nutritional status in pregnancy. I cannot emphasise that enough.”


Kerry Gould: every individual’s route out of depression is unique, photo Bradley Ambrose.

Where does this leave traditional mental health treatment, such as psychological counselling and therapy? It’s still very important for most people with depression, say both Codyre and Ferguson.

Psychologist Kerry Gould, who has been counselling families and young people for about 25 years, describes how depression is “life-constricting” in its effect. The causes are very real, and every individual’s route out of depression is unique because it’s based on their individual biology and individual history, he says.

“So you have to gather people’s resources to help counteract their vulnerabilities. Everybody has a lot of resilience; you just have to help them find it. “It’s the old stressors that trip us up. That’s why we need extra help to handle it. If we could handle it ourselves we would have already done so.”

Meanwhile, Ferguson is encouraged that molecular biologists are now talking directly to clinicians. Over the past decade, he’s attended a dozen conferences to extend his understanding of the issues. “There are these little silos of highly specialised knowledge that are allowing clinicians to access very high-powered biochemistry.”

He hopes more doctors will investigate the courses being offered by the Australasian College of Nutritional and Environmental Medicine. And that once the epigenome has given up its secrets, the treatment of depression will become more sophisticated, more targeted and more effective. Says Codyre: “Over the next 10 years, we’re going to get serious about this stuff. The evidence is so strong – it’s unethical not do something about it.”

Way to go

Psychiatrist David Codyre’s non-medical strategies for treating depression and anxiety:

    • Eat fresh, unprocessed nutritious food. An Australian study found that people who eat a diet high in fresh vegetables, fruit, fish, meat and whole grains are significantly less likely to be depressed or anxious than those who eat highly processed, sugary and fried foods and refined grain and drink beer and other alcohol.

    • Take basic supplements such as omega-3 fish oil. You need enough to get around 1000mg of EPA (eicosapentaenoicacid) a day.

    • A combination of zinc, vitamin B6 and magnesium is important for mood.

    • Get some sunshine – vitamin D – every day for a mood lift.

    • Get your heart rate up at least three to five times a week by doing vigorous exercise – walking, running, dancing or playing sport.

    • Accomplish something every day – something you’ve been putting off, like paying a bill.

    • Give yourself a treat every day – watching a favourite TV programme, having a bubble bath, fishing, surfing or spending time in the shed.

    • Create a gratitude diary. List things you’re grateful for, such as “I’m grateful to talk to my friend Peter”; “meet Helen for a coffee”; “finish my assignment”.

The black cat blues

After decades of depression, an Auckland woman credits supplements with keeping her on an even keel

depression Photo/Thinkstock

Mary (not her real name) has battled depression since her teens. A class captain and keen netball player, she began feeling unwell when she was about 15. “I remember going to bed at night thinking, ‘I wonder when the world’s going to end?’ My mood was like a black cat stalking me in the night.”

Her father was an alcoholic and much older than her mother. She spent her first two years living with an aunt. Once she finished school, she left home to study nursing and loved it. She went on to study psychopaedic nursing at the now-defunct Templeton Hospital in Christchurch. “The first episode was when I came back to Auckland. I was 22. I couldn’t get out of bed, couldn’t look in the mirror, couldn’t read. I was six months in that black hole before I worked my way out of it.”

Since then, the “black cat” has continued to creep into her life. “It hurts in here,” she says, pressing her hand to her chest. “I can feel it coming on; it terrifies me. Even now that I’m better, I’m frightened it’ll come and get me.”

As a young mother, she struggled to cope with breastfeeding, PMT and renovating an old house. “I had several periods of depression,” she says. “But although I was seeing a doctor, I never went on anti-depressants.” Instead, she used alcohol. After 10 years and three children, her marriage broke up and her alcohol dependence worsened. Although her GP continued to offer her anti-depressants, she tried to mask her symptoms for fear of the stigma associated with depression.

Two years ago, she collapsed and was taken from Great Barrier Island to Auckland Hospital by helicopter, but even then she refused help. “I told the docs I was okay, pulled my drip out then went and lived in a tent at Muriwai camping ground.”

Only after a month did she acknowledge she had a problem and went into rehab. It worked. She joined a church, got a job at a home for the elderly and, on the recommendation of her GP, William Ferguson, agreed to take antidepressants as well as a mix of supplements. “It costs about $60 a month, but it’s worth it,” she says. “The effect is of keeping me on an even keel. And blood tests have shown I am on an even keel. I have fewer highs and lows. It’s a feeling of being present in the here and now, and not one of being on drugs.”

But she’s sad that it’s taken about 40 years to take charge of her life. “My gut feeling is that it’s all to do with my biochemistry. I keep thinking, if I’d had help and been diagnosed with depression at a young age, my life would have been different. I might have been closer to my children. Maybe my marriage would have lasted …”

She’s looking forward to the birth of her first grandchild, which an improved relationship with her daughter means she can share to the full. “It’s lovely to feel present at Jane’s upcoming delivery. I’m 55 now and I’ve never felt like this before. Looking back, I wish I’d had a GP like William in my twenties. I don’t know how I got through.”

Supplementary members

Most of GP William Ferguson’s patients didn’t want to talk publicly about their treatment. But several were happy to talk anonymously about how supplements, including SAMe (s-adenosyl methionine) and folic acid in its various forms, steadied them and made them wake up in the morning happy to be alive.

Frances (not her real name) says her life has become carefree. “Things seem to stay in proportion. And best of all, when I do have the occasional meltdown, I pull out of it much more quickly. It used to take me three days to get over a row, now it’s more like an hour.”

Jane, who’s had mental health problems most of her life, talks about a new feeling of stability. “I used to feel anxious all the time, which would occasionally erupt into uncontrollable tantrums, usually directed at my children and husband – the people I loved most.

“That would leave me exhausted for days afterwards – and looking back they were probably responsible for the break-up of my marriage and other relationships. Although most of my family tends to be anxious, we’ve always avoided antidepressants. However, taking a nutritional supplement like SAMe was okay. And since I started it, the tantrums have completely disappeared."

This article was first published in NZ Listener.


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