Nutrition in Mental Health - Sounding the alarm
In general medicine the alarm has been sounded about the health effects of the post-industrialisation Western diet on our bodies and our minds.
There has been a move from whole foods to processed foods favouring durability, transportability, palatability and convenience over nutrition. There is little dispute about the associations between diet and chronic disease including cardiovascular disease, myocardial infarction, type II diabetes, cancers and obesity. Now that same alarm is being sounded in mental health as epidemiologic, basic scientific, and clinical evidence show that diet both influences risk for, and outcomes of mental health disorders.
Deficiency of B12 and folate have been known to be a cause of depression and cognitive dysfunction for some time. But gross deficiency is not the only means by which diet might affect mental health. It is becoming clear that psychiatric disorders share many of the same disease pathways as chronic medical problems including immune dysregulation, chronic inflammation, oxidative stress, mitochondrial dysfunction, alterations in the gut flora (microbiome), and epigenetic changes, perhaps helping to explain the high rates of psychiatric comorbidity with obesity, cardiovascular disease, autoimmune disorders and type II diabetes.
It is now known that the Western diet can drive pathophysiological change at each of these pathways and is a risk factor for the development of depression (throughout the life course including prenatal maternal diet affecting the risk of internalising and externalising behaviour in offspring), anxiety and may play a role in increasing the risk of developing psychosis in high risk individuals.
A series of large population studies from Scandinavia, Spain and Greece showed a clear association between depression and anxiety and diet quality, with a whole food, mediterranean style diet having the lowest risk. Similar studies have demonstrated similar inverse relationships between depression and diet low in processed foods in Asian populations. One recent neuroimaging study demonstrated an inverse relationship between hippocampal volume and diet quality in older adults. Furthermore these studies were controlled for a range of confounders including age, sex, socio demographic status, smoking and education levels. Several prospective trials have begun to address the issue of reverse causality. Unfortunately clinical trials of dietary interventions in psychiatric disorders are methodologically complicated, particularly in maintaining adherence to the dietary intervention and due to the nature of cognitive and behavioural changes in psychiatric disorders.
The number of clinical trials on individual nutraceuticals in psychiatric disorders is also growing. A trial of omega 3 essential fatty acids in young people at high risk of developing psychotic disorders demonstrated a significant protective effect reducing risk of progressing to a psychotic disorder from 40% to 3%. Animal trials have showed transplanting bowel flora from anxious mice to non-anxious mice (after sterilisation of their own bowel flora) induced similar anxiety states and giving probiotics to healthy men helped reduce physiologic and psychological stress with modest improvements in cognitive function.
Nutrients of particular interest in psychiatric disorders include omega 3 essential fatty acids, B vitamins, choline, minerals such as zinc and magnesium, pre and probiotics, S-adenosyl- Methionine (SAMe), a variety of plant chemicals with anti-inflammatory and antioxidant properties such as curcumin, the yellow pigment found in Turmeric or the compounds known as polyphenols including resveratrol.
While conducting intervention trials for dietary interventions are methodologically fraught the lack of randomised controlled trials should not prevent addressing the health of patients with psychiatric disorders holistically. At the very least it will help address the significant physical comorbidity such as metabolic syndrome and has every chance of improving outcomes for their mental health. Moving beyond the individual patient, it is considered that the food industry is at an equivalent point to the tobacco industry in the 50’s and further scrutiny and regulation, along with raised consumer consciousness has the potential to deliver a cost effective and efficacious mental health intervention at the population level.
“...it is considered that the food industry is at an equivalent point to the tobacco industry in the 50’s...”
Jacka FN, Pasco JA, Mykletun A, Williams LJ, Hodge AM, O’Reilly SL, Nicholson GC, Kotowicz MA, Berk M: Association between western and traditional diets and depression and anxiety in women. Am J Psychiatry 2010, 167:305-311
Jacka FN, Mykletun A, Berk M, Bjelland I, Tell GS: The association between habitual diet quality and the common mental disorders in community-dwelling adults: the Hordaland Health study.Psychosom Med 2011, 73:483-490.
Sanchez-Villegas A, Delgado-Rodriguez M, Alonso A, Schlatter J, Lahortiga F, Majem LS, Martinez-Gonzalez MA: Association of the Mediterranean dietary pattern with the incidence of depression: the Seguimiento Universidad de Navarra/ University of Navarra follow-up (SUN) cohort. Arch Gen Psychiatry 2009, 66:1090-1098
Sanchez-Villegas A, Toledo E, de Irala J, Ruiz-Canela M, Pla-Vidal J, Martinez-Gonzalez MA:Fast-food and commercial baked goods consumption and the risk of depression. Public Health Nutr 2012, 15:424-432.
Akbaraly TN, Brunner EJ, Ferrie JE, Marmot MG, Kivimaki M, Singh-Manoux A: Dietary pattern and depressive symptoms in middle age. Br J Psychiatry 2009, 195:408-413.
Chatzi L, Melaki V, Sarri K, Apostolaki I, Roumeliotaki T, Georgiou V, Vassilaki M, Koutis A, Bitsios P, Kogevinas M: Dietary patterns during pregnancy and the risk of postpartum depression: the mother-child ‘Rhea’ cohort in Crete, Greece.Public Health Nutr 2011, 14:1663-1670
Sanchez-Villegas A, Toledo E, de Irala J, Ruiz-Canela M, Pla-Vidal J, Martinez-Gonzalez MA:Fast-food and commercial baked goods consumption and the risk of depression.Public Health Nutr 2012, 15:424-432.
Nanri A, Kimura Y, Matsushita Y, Ohta M, Sato M, Mishima N, Sasaki S, Mizoue T: Dietary patterns and depressive symptoms among Japanese men and women. Eur J Clin Nutr 2010, 64:832-839.
Aihara Y, Minai J, Aoyama A, Shimanouchi S: Depressive symptoms and past lifestyle among Japanese elderly people. Community Ment Health J 2011, 47:186-193.
Liu C, Xie B, Chou CP, Koprowski C, Zhou D, Palmer P, Sun P, Guo Q, Duan L, Sun X, Anderson Johnson C: Perceived stress, depression and food consumption frequency in the college students of China Seven Cities. Physiol Behav 2007, 92:748-754.
Kuczmarski MF, Cremer Sees A, Hotchkiss L, Cotugna N, Evans MK, Zonderman AB: Higher Healthy Eating Index-2005 scores associated with reduced symptoms of depression in an urban population: findings from the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) study. J Am Diet Assoc 2010, 110:383-389
Felice N. Jacka, Nicolas Cherbuin, Kaarin J. Anstey, Perminder Sachdev and Peter Butterworth. Western diet is associated with a smaller hippocampus: a longitudinal investigation. BMC Medicine 2015, 13:215
Jacka FN, Ystrom E, Brantsaeter AL, et al. Maternal and Early Postnatal Nutrition and Mental Health of Offspring by Age 5 Years: A Prospective Cohort Study. J Am Acad Child Adolesc Psychiatry. 2013; 52(10):1038-47
Bravo JA, Forsythe P, Chew MV, Escaravage E, Savignac HM, Dinan TG, Bienenstock J, Cryan JF. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):16050-5. doi: 10.1073/pnas.1102999108. Epub 2011 Aug 2
Dr Clayton Smith
Dr Clayton Smith FRANZCP is a psychiatrist in private practice in Burwood, Sydney and also provides consultancy and supervision at The Mindspot Clinic, an internet delivered Cognitive Behaviour Therapy treatment program. He has a particular interest in the management of anxiety disorders and behavioural therapy, in particular, Acceptance and Commitment Therapy.
Insteading has created a bumper trove of gardening resources, including those designed...
A report led by the University of Western Australia reveals that the pandemic has put many...
The PD Warrior program has arrived in Sydney's north-west, with the potential to improve the...