Study finds that overall healthy diet may protect against depression in middle age

On Monday I wrote about omega 3 fats and how they are important for brain function and in protecting against and treating depression.  Today I wanted to look at a UK study which has just been published in the British Journal of Psychiatry (1).

The study authors (1) wanted to examine the association between overall dietary patterns and depression.  Data from over 3000 participants aged around 55 years was analysed.  Two main dietary patterns were found in the participants.  A ‘whole food’ pattern which was high in vegetables, fruit and fish and a ‘processed food’ pattern which was high in sweetened desserts, friend foods, processed meats, refined grains and high-fat dairy products.  Self reported depression was assessed in the study participants 5 years after the initial dietary analysis.  A special reputable scale, called the Center for Epidemiologic Studies – Depression (CES–D) scale, was used to make the assessment.  The study showed that participants who adhered most strongly to the ‘whole food’ pattern of eating had a significantly lower risk of depression.  Those individuals with the highest consumption of processed foods had the highest risk of depression.  The authors conclude “In middle-aged participants, a processed food dietary pattern is a risk factor for CES–D depression 5 years later, whereas a whole food pattern is protective”.(1)

The study is interesting as it looks at diet as a whole rather than individual nutrients or components.  The study shows that eating healthily and including a high proportion of vegetables, fruits and fish is associated with protection against depression in middle-age.  Processed and refined foods can not only damage our health they also seem to impact our mood.   Specifically, the researchers in the study found that (1) participants whose diet was high in processed foods had a 58% higher risk of receiving a CES-D depression rating five years later.  The study does not prove that a processed food diet causes depression, it simply shows an association or a link, it could be, for example, that people who become depressed become inclined to eat more processed foods or that there is a yet undiscovered factor behind the association.

However, the results of this study show a strong association and are interesting, when added to results from several other studies there is certainly a suggestion that a healthy diet does protect against mental illness.  Eating a high quality, healthy and nutritious diet is important for overall health an wellbeing.  Vegetables, fruits, beans/pulses, unprocessed meats and oily fish are important components to consider.  If you are concerned that your diet consistently falls short then you may wish to consider taking an omega 3 fatty acid supplement together with a good quality food-state multivitamin and mineral supplement.  It is important to be clear that supplements can never be viewed as a replacement for a healthy diet.

(1)Akbaraly TN et al.  2009.  Dietary pattern and depressive symptoms in middle age.  The British Journal of Psychiatry.  195:408-413
Written by Ani Kowal