Role of nutritional factors in depression is subject to increasing research interest.Studies have indicated roles for folate, vitamins, omega fish oils, chocolate, tomatoes etc. Prospective studies have examined the role of dietary patterns as well. A recent prospective study of UK office workers found some evidence that a higher consumption of the ‘whole food’ diet, characterised by high intakes of vegetables, fruits and fish, was associated with fewer depressive symptoms 5 years later (Akbaraly et al 2009).
Mediterranean diet: This is reported to be associated with better physical health. A hallmark of this diet is the abundant use of olive oil, which is rich in monounsaturated fatty acids (MUFAs) and low intake of meat and meat products. This diet generally have 1) high ratio of MUFAs to saturated fatty acids (SFAs), (2) moderate alcohol intake, (3) high intake of legumes, (4) high intake of cereal (such as bread), (5) high intake of fruit and nuts, (6) high intake of vegetables, (7) low intake of meat and meat products, and (8) moderate intake of milk and dairy products. (9) high fish intake.
J Rienks AJ Dobson and GD Mishra investigated the association between dietary patterns and prevalence and incidence 3 years later of depressive symptoms using data from the mid-aged cohort ( more than 10000 participants) in the Australian Longitudinal Study on Women’s Health. Depression was assessed by self reported symptoms in the previous week. Dietary pattern was studied using the self report of usual consumption of various food items over the last 12 months.
Findings: Participants were classified in to six different dietary patterns.After adjusting for socio demographic and lifestyle factors, the ‘Mediterranean-style’ dietary pattern was found to have both a cross-sectional and prospective relationship with the latter showing a 17% reduction in the odds of reporting incidence of depressive symptoms 3 years later. Most interestingly, women in the highest intake quintile of the ‘Mediterranean-style’ pattern were less likely to report subsequent depressive symptoms by more than a third.( dose response relationship).vLimitations: Association is tested in a women only cohort.Information on depression and diet is self reported. Even though most confounders were taken in to account, residual confounding could still be present as there maybe unmeasured (e.g.: family history of depression and personality traits) or imprecisely measured confounders (such as physical activity). Food questionnaires have limitations, for e.g. the one used in this study did not ask about olive oil consumption.
Conclusions: Mediterranean-style diet may have protective effect against depression in middle-aged women.
Summary of the article:
Mediterranean dietary pattern and prevalence and incidence of depressive symptoms in mid-aged women: results from a largecommunity-based prospective study. Rienks J, Dobson AJ, Mishra GD.Eur J Clin Nutr. 2013 Jan;67(1):75-82