br Diet or Supplements Supplements

Diet or Supplements? Supplements in nutrition interventions have often been used to avoid the difficulties of addressing dietary intakes; however, it needs to be stressed that diet and nutritional supplements are not equivalent (Lichtenstein and Russell, 2005) and data supporting the utility of such supplementation in mental illness are somewhat limited and equivocal to date. The exception to this is omega-3 fatty ribosomal s6 kinase supplements, which have a more extensive evidence base, particularly for the use of supplements containing a higher proportion of EPA compared to DHA (Sublette et al., 2011) and as an adjunctive treatment for mood disorders including bipolar depression (Sarris et al., 2012). Sarris et al. reviewed the literature on nutritional supplements for major depressive disorder and found little support for these as monotherapies, but concluded that there was evidence for the utility of folic acid, S-adenosyl-methionine (SAMe), omega-3 fatty acids, and L-tryptophan as adjunctive therapies (Sarris et al., 2009). A more recent systematic review and meta-analysis of nutraceuticals as adjunctive therapies for depression confirmed the efficacy of SAMe, omega 3, methylfolate and Vitamin D, but provided only limited support for zinc, folic acid, vitamin C, and tryptophan (Sarris et al., 2016). Almeida et al. also conducted a recent systematic review and meta-analysis of the literature on the short and long term impact of Vitamin B12 and folate as a treatment for depression (Almeida et al., 2015). They concluded that the evidence did not support these B-group vitamins as a short-term treatment, but that they might offer some preventive potential over the longer term. Other nutraceuticals with methods of action focused on addressing the pathophysiological aberrations that characterise many psychiatric disorders, such as inflammation, oxidative stress, reduced neurogenesis, and mitochondrial dysfunction, have shown considerable promise. For example, N-acetyl cysteine (NAC) – a bioavailable amino acid that upregulates glutathione and modulates glutamatergic, neurotropic, and inflammatory pathways – has shown preliminary efficacy as an adjunctive treatment in schizophrenia and bipolar depression (Berk et al., 2008a,b), but not in major depressive disorder (Berk et al., 2014). Finally, some in the field have argued that the use of single nutrient supplements is flawed as a strategy, given that nutrients are not ever consumed singly in the diet and that humans have evolved to require a broad range of nutrients. In their recent systematic review, which included open label trials and case studies in addition to randomised placebo-controlled trials, Rucklidge and Kaplan (2013) noted the lack of trials of combined multivitamin-mineral formulations in populations with clinical depressive, anxiety or psychotic disorders. However, two randomised, double-blind, placebo-controlled trials of such formulations in adult ADHD (Rucklidge et al., 2014) and for antisocial behaviour in young adult prisoners (Gesch et al., 2002) offer support for such an approach to treatment. Certainly, an assumption that greater efficacy might be attainable using simultaneous and synergistic combinations of nutraceuticals has merit, and a trial of a multi-component nutrient formula, in combination with NAC, for the treatment of bipolar depression is currently underway (Dean et al., 2015). More research in this field is warranted and this is discussed further below.
Where to Now? The field of Nutritional Psychiatry is only just starting to generate data of the quality and consistency required to change public health recommendations and clinical practice. However, we have recently argued for such changes on the basis of the precautionary principle and the imperative to find new ways to address the very high burden of illness associated with mental disorders, and the fact that these are shared risk factors across the suite of non-communicable disorders with which mental disorders are so commonly comorbid (Dash et al., 2016). Such recommendations, including dietary recommendations (Opie et al., 2015b), are also cognizant of the substantial burden of disease associated with the profound and detrimental changes to food systems globally (G. B. D. Risk Factors Collaborators et al., 2015) and the urgent need for governments to address food policy to support better population health (Jacka et al., 2014b).