Researchers in Tehran investigated whether the level of variety in the daily diet is related to stress and depression in women.
Mental health issues are an increasing global concern. The World Health Organization (WHO) estimates that depressive disorders make up the third largest burden of disease worldwide. Several studies have highlighted the importance of a healthy diet in preventing and treating mental disorders. These have often focused on the consumption of particular nutrients, but it is also important to evaluate overall dietary patterns. Researchers in Tehran, Iran investigated the relationship between the level of diversity in daily diet and depression in women attending health clinics. They reported their findings in the Annals of General Psychiatry.
The study recruited 360 women, between 20-49 years old, attending 10 different health centres in the south of Tehran. Women previously diagnosed with depression or physical illnesses, pregnant women, or those following specific diets were excluded from the study.
Assessing Psychological Status
Researchers assessed the psychological status of the women using the Depression, Anxiety and Stress Scales (DASS) questionnaire. This is a 42-item questionnaire which identifies symptoms of stress and depression. Based on their scores, participants were classified into three groups: normal mood, mild or moderate depression, or severe depression.
Participants also completed a 24-hour diet recall questionnaire in a face-to-face interview. The questionnaire asked about food consumed in the last 24 hours in nine main food groups: cereals; dark green leafy vegetables; vitamin A rich fruit and vegetables; other fruits and vegetables; organ meat (offal); meat, fish and seafood; eggs; legumes, nuts and seeds; milk and milk products. The questionnaire allows the calculation of a Dietary Diversity Score which gives a measure of the variety in the daily diet.
Increased Variety in Diet Related to Decrease in Risk of – Severe Depression
The prevalence of depression and stress amongst the participants was 31.4% and 25.8% respectively. There was a positive relationship between the Dietary Diversity Score and the intake of energy, protein, carbohydrate, fat, vitamins A, B6, B12, folic acid and other nutrients. A one-unit increase in the Dietary Diversity Score led to 38% reduction in the risk of severe depression. This relationship remained significant after adjusting for other factors which may influence the result. No association was found between the Dietary Diversity Score and mild or moderate depression, or stress.
The authors point out that there were some limitations to this study. This was a relatively small study, and the 24-hour dietary recall questionnaire only provides a snapshot of an individual’s overall diet. Also, lack of variety in diet could be a consequence rather than a cause of depression. However, the findings are in line with previous studies which have shown that a balanced, varied diet, (a “Mediterranean” pattern diet) with a higher Dietary Diversity Score can be protective against depression. This could be an important intervention in promoting mental health and further research is needed.
Written by Julie McShane, Medical Writer
Reference: Poorrezaeian M, Siassi F, Milajerdi A, et al. Depression is related to dietary diversity score in women: a cross-sectional study from a developing country. Ann Gen Psychiatry (2017) 16:39. DOI 10.1186/s12991-017-0162-2.
