Is it just me?
Am I the only one who feels uncomfortable when reading articles that assert that a focus on nutrition – the vitamins and minerals we ingest – could be a solution to the world’s mental health crisis? In the last couple of years, I’ve encountered an increasing number of such claims and my immediate response has been to do what I always do when faced with information that does not fit with my existing view: ignore it or file it away in the virtual cabinet labelled, ‘Too difficult to think about’. Or, alternatively, dismiss it while muttering that nutritional approaches offer nothing more than a confirmation that good physical health enhances general contentment; so what?; obvious isn’t it?; no big deal.
I’m a longstanding critic of the dominant bio-medical approach to human suffering, with its spurious assumptions about brain abnormalities and chemical imbalances, and instead lean much more towards the idea that life adversities are the most potent contributors to distress and overwhelm. So when I stumbled upon an online article by the Independent with the headline, ‘WHY NUTRITIONAL PSYCHIATRY IS THE FUTURE OF MENTAL HEALTH TREATMENT’, I experienced that familiar wave of discomfort – like a bigot reading something that did not fit with his long-held prejudices – and started to implement my ignore-and-dismiss tactic. But, on this occasion, I paused, reflected on the fact that I know hardly anything about ‘nutritional psychiatry’, and decided to find out more.
My quest for further information
I read the whole of the Independent article, while trying to keep my internal critic in check. I read that a lack of essential nutrients contributes to the onset of ‘mental disorders’ (yuk, the language of biological psychiatry); that psychiatrists are only now becoming aware of the benefits of using nutritional approaches to mental health and are ‘calling for their peers to support and research this new field of treatment’ (clearly, the self-serving psychiatry profession jumping on the bandwagon); that ‘many mental health conditions are caused by inflammation in the brain’ (more internal deficit, illness-like-any-other mumbo jumbo); and that food supplements such as zinc, magnesium, omega 3, and vitamins B and D3 can ‘improve people’s mood, relieve anxiety and depression, and improve the mental capacity of people with Alzheimer’s disease’ (where’s the evidence for these bold claims?).
Cynicism to the fore, I searched online for more information and found a section on ‘diet and mental health’ on the website of the Mental Health Foundation, a UK charity. Here I read that, ‘Nearly two thirds of those who do not report daily mental health problems eat fresh fruit or fruit juice every day, compared with less than half of those who do report daily mental health problems.’ The article reported similar findings for fresh vegetables, salad, organic foods and meals made from scratch (all associated with better mental health) as compared to chips, crisps, chocolate, ready meals and takeaways (all associated with poorer mental health). At this point, my dissonance-fuelled discomfort started to fade as I realised there was one simple explanation for these reports: the dietary differences represent an index of social deprivation, the variation in mental health outcomes being more likely the result of greater life adversities in the economically poorer group.
Reassured by this conclusion, one totally consistent with my existing viewpoint, I almost ended my search for information. I resisted the temptation, however, and enrolled on a Mad in America continuing education course, titled ‘Nutrition and Mental Health’, a three-lecture online course delivered by Dr Bonnie Kaplan (a Professor of Medicine) and Dr Julia Rucklidge (a Professor of Clinical Psychology). And I’m so glad I did.
So where’s the evidence?
I learned lots of interesting stuff from Drs Kaplan and Rucklidge. How the benefits of diet for mental health were highlighted by Mrs Beaton in her household management book published in the 19th-century. Fascinating biological facts: the brain is responsible for up to 50% of a person’s metabolic activity; and that we are ‘only 10% human’, with 90% of our cells being comprised of microbes, most of them located in the gut. And how the typical Western diet is grossly deficient in vitamins and minerals as a result not only of poor menu choices, but also the depletion of nutrients in our soil and crops (partly a consequence of modern herbicides) – based on this premise, the lecturers refute the ‘eat a balanced diet and you’ll be fine’ assertion.
In studies of efficacy, the presenters argue that it does not make physiological sense to investigate nutrients one at a time; they work synergistically, the total effect being greater than the parts, so cocktails of vitamins and minerals are used. Furthermore, the doses of supplements investigated in the research literature are many-times larger than those obtained over the counter in natural health shops.
So how strong is the evidence that vitamins and nutrients can significantly improve mental health? There are, of course, the intriguing (but inconclusive) cross-sectional findings; a range of studies reporting that people who eat traditional, unprocessed Mediterranean diets suffer less symptoms of anxiety and depression than those eating Western processed diets. More persuasive are the prospective studies where a nutrient-focused intervention corresponded to subsequent mental health benefits: the ‘Whitehall study’ in the UK followed up two groups (those eating mostly process food v those eating mostly whole food) over a five-year period and found significantly fewer depressive symptoms in the latter; omega-3 fatty acid supplements with young people at high risk of psychotic experiences were associated with a significant reduction in subsequent psychotic episodes when compared to a placebo; in the aftermath of an earthquake, people with an ‘ADHD’ diagnosis who continued to take micro-nutrients were significantly less stressed than those who ceased to take them; and the ‘Minnesota Starvation Experiment’ where healthy students who were given a nutrient-deficient diet for 24 weeks described more depressive symptoms, hysteria, apathy, social withdrawal and concentration problems as compared to their counterparts who continued with a normal diet.
All these findings are interesting, and suggest that nutrients might impact upon our emotional wellbeing, but where are the randomised controlled trials? Well, apparently, there are more than two-dozen of them where micronutrients performed better than placebo with regards to a range of mental health problems, including aggression, anxiety, autism, ‘PTSD’ and ‘ADHD’. Furthermore, a recent controlled trial in Australia involving 176 people with ‘major depression’ (the ‘Smiles study’) compared ‘nutritional counselling’ with ‘peer group support’ and found that the dietary group achieved a significantly greater reduction in depressive symptoms.
So, after my first sortie into the ‘nutritional psychiatry’ literature, what are my initial impressions?
There are positives. I’ve learnt that there is a substantial evidence base supporting the premise that the ingestion of cocktails containing very high levels of micronutrients can achieve a beneficial impact on a range of symptoms associated with mental health problems. The side effects of these mineral and vitamin binges seem very rare, thereby avoiding the iatrogenic harm of widespread prescribing of psychiatric drugs. Furthermore, should this approach gain in popularity, there would be economic advantages for our cash-strapped health services, the cost of micronutrients being much less than that of pharmaceuticals.
There are, however, some limitations and valid concerns. First – and arguably the most worrying prospect – is that the suggestion of an important link between nutrition and mental health is likely to be seized upon by biological psychiatry to promote more brain-defect theories of human distress. Ominous signs of this trend are evident when one looks at psychiatric researchers’ speculations about the process by which minerals and vitamins might impact on emotional wellbeing. The scientific papers on this subject already contain references to ‘brain inflammation’, ‘oxidative stress’, ‘enhanced brain plasticity’ and ‘co-factors in the enzyme chain for neuro-transmitters’ as potential explanations. And a lament of Bonnie Kaplan – one of the presenters on the Mad in America course – is that almost all papers that discuss brain inflammation as the mediator of the nutrient-mental health link call for more anti-inflammatory drugs rather than dietary changes.
A further limitation is with regards to the research findings. As far as I can ascertain, the evidence does not suggest a ‘dose-response’ relationship between micronutrients and benefits to mental health. In other words, the results of the relevant studies fail to show that increasing the amounts of minerals and vitamins ingested corresponds to incremental improvements in emotional wellbeing, a relationship that one would expect to find if the dietary supplement was causative. Similarly, there is little evidence to suggest that those people whose blood tests reveal low levels of micronutrients at the start of a study gain greater benefit from dietary supplements as compared to those with normal levels at baseline. So, although the potential link between food supplements and human distress is an intriguing one, worthy of further investigation, we should guard against any premature, magic-bullet conclusions that the current epidemic of mental health problems can be resolved by a population-wide nutrient splurge.
And one final thought. If it could be robustly demonstrated that increasing our intake of vitamins and minerals led to pervasive and sustainable benefits in emotional wellbeing, the term ‘nutritional psychiatry’ would be a misnomer; more appropriate names for this line of enquiry would be ‘nutritional science’ or ‘dietetics’.
Photo courtesy of KEKO64 at FreeDigitalPhotos.net