By Bonnie Kaplan
The relationship between nutrition and mental health is one we have been discovering and rediscovering for 2,600 years. The biblical Book of Daniel describes what may be the first clinical trial of the effect of diet on mental function: During the Babylonian exile (586–538 BC), Daniel and a group of his Israeli friends consumed only legumes and water, then were compared to young men who ate “royal food” during that time (we can only guess at the nature of the royal diet). After 10 days, King Nebuchadnezzar concluded that the appearance of the Israeli men was superior and that “in all matters of wisdom and understanding, that the king inquired of them, he found them ten times better….”
If ancient history does not impress you, go back just one century. The 1910 People’s Home Medical Book, which guided western pioneers and homesteaders who did not have access to urban centres for their health, indicates that the number one cause of mental illness was “imperfect nutrition.”
Scientists took note. From the 1920s until about 2000, misguided researchers studied one nutrient after another, looking for a silver bullet cure for mental illness. Many studies found enticingly positive effects, especially for some B vitamins; vitamins C, D and E; and minerals such as chromium, iron, magnesium and zinc. But it is only in the 21st century that scientists have returned to basic knowledge of human nutrition are looking at human physiological needs across a spectrum.
Large epidemiologic surveys from the United Kingdom, Spain and Australia have found associations between healthy diet and better mental health, as have prospective studies. A 2011 study in PloS One found that poor diet predicted poor mental health in adolescents. The Archives of General Psychiatry published a study in 2010 which found that dietary intervention with adolescents and young adults at risk for psychosis prevented the progression of symptoms over one year.
But can we conclude that mental health problems can be treated nutritionally? A growing body of literature suggests that possibility, as long as the nutrient intervention involves a broad spectrum (no more silver bullet thinking!) and the interaction between nutrient treatment and medication is not ignored.
With a few exceptions, the multi-ingredient research has only begun to be published. Since 2000, research on such formulations has accelerated, particularly in physical health. But recent research has also found evidence for mental health. A study published in 2000 in Psychopharmacology found that compared to placebo, a broad spectrum formulation decreased anxiety in a sample of 80 men. A 2011 issue of Psychiatric Research reported similar results among people affected by the 2010 New Zealand earthquakes.
The most-studied broad spectrum formula in the world is actually Canadian. The Truehope formula consists primarily of vitamins and minerals, amino acids and antioxidants. The 16 or so reports on its efficacy have come from independent investigators in Canada, New Zealand and the United States. In case studies, within-subject crossover designs, open-label case series and large database analyses, this formula seems to show promise for treating bipolar symptoms and explosive rage in adults and adolescents. In a study published in 2010 in the Journal of Child and Adolescent Psychopharmacology, this formula was associated with significantly greater improvement than conventional medication for symptoms associated with autism. One carefully documented case of childhood psychosis also showed response to nutritional intervention, as presented in a 2009 issue of the same journal. A case study in a 2009 issue of the Journal of Anxiety Disorders found that micronutrient treatment worked for obsessive-compulsive disorder.
Several important randomized control trials have also demonstrated an impact on antisocial and violent behaviour. A 1997 study in the Journal of Nutritional and Environmental Medicine reported a 28 per cent difference in rule violations in 62 imprisoned delinquents who received a daily micronutrient supplement when compared to those who received a placebo. In another study, published in 2000 in the Journal of Alternative and Complementary Medicine, 80 schoolchildren aged 6 to 12 received either a broad micronutrient supplement or placebo. Those on the supplement had a 47 per cent lower mean rate of antisocial behaviour than the placebo group. A randomized control trial that is often erroneously cited as an investigation of a single ingredient (essential fatty acids) found a 35 per cent decrease in disciplinary incidents for 231 young offenders who received a supplement consisting of 25 vitamins and minerals, plus essential fatty acids, compared with a reduction of only 6.7 per cent in those receiving a placebo. These findings were replicated in the Netherlands, with results reported in 2010 in Aggressive Behavior.
Yet despite such findings, the debate about the role of diet in mental health treatment and prevention continues. Natural health care practitioners argue that a good diet, often with supplements, can play a primary role in preventing and curing mental illness without drugs. Mainstream mental health professionals, on the other hand, take the position that diet is too simple of a consideration.
But advocating the role of diet in prevention, management and treatment does not imply an anti-psychiatry stance. Psychiatric medication is important. But in my ideal world, we would treat first with micronutrients, and medication would sometimes be used as a supplement, instead of the other way around. Psychiatry can learn from other medical professions that are leap years ahead, using nutrients for infectious disease, wound healing and gut problems. It simply makes sense.
Dr. Bonnie Kaplan is a research psychologist in the Faculty of Medicine at the University of Calgary, where she studies nutrition in relation to brain development and function