Is there an association between a high fat diet and depression: systemic review of observational studies?

Abstract

Introduction Depression affects people in all community worldwide and significantly contributes to global burden of disease. Estimate of more than 350 million people are affected by depression. It is the leading cause of disability worldwide. Diet is an important biophysiology factor that plays a central role in the overall health of an individual. Studies have shown that healthier eating pattern is associated with better health outcomes including mental health. 2 From preventive health perspective findings, association between fatty diet and depression can be applied in evidence-based primary care of depressive symptoms. 3 Recently there is emerging evidence that links nutrition pattern to risk of depression. Depression relates to biomarkers of short and long term polysaturated fatty acid intake. There are so many studies on nutrition and depressive symptoms. However there are no enough data on association between high fat diet and depression. The aim of this review is to assess if there is relationship between fat content of the diet and depression. Materials and methods The study design compromises of cohort studies cross sectional designs and case-control study published within ten years of the review. Ten databases were searched for observational studies on the association between fatty diet and depression. The search was limited to English Language report. Search term was diet, nutrition, ω-3 fatty acid, PUFA, MUFA and depression/depressive symptoms. Inclusion criteria for the review includes one quantitative assessed dietary variable in the analysis with depression or depressive symptoms as outcome. The study must have a validated tool for dietary assessment such as food frequency questionnaire with at least 35 validated items. Assessment of depression should be based on a standard measurement such as physician diagnosis or initiation of anti-depressant etc. Some selected articles and reviews in the references were tracked to see if they met the inclusion criteria. For articles included in the review, the following information were obtained; the author's name and publication year, setting and study design, data analysis, subject characteristics (age and sex), dietary assessment instrument, depression assessment tool, adjusted variable (if any) and the main findings. Abstract Background: There are many studies on association between some biological factors and depression. However there are not too many studies showing association between depression and fatty diet. The aim of this study is to provide a systemic review on association between depression and fatty diet.