Over the years various lines of enquiry have pointed to the fact that mood is affected by food. Not uncommonly, the focus has tended to be on particular types of sugary or fatty foods along with their nutritional value, or lack of. Most people, for example, have heard of the benefits of the Mediterranean diet in so far as it appears to protect against certain cardiovascular problems and possibly even depression. Of course for many of us the Mediterranean diet is either something unfamiliar or at least does not constitute our main daily diet.
Recently, the British Journal of Psychiatry reported the effects of two different types of dietary patterns and their effects on depression. Over three thousand middle-aged adults (average age 55, 26 percent of the sample women) were monitored over a period of five years. Participants in the study were categorized into those whose diets included whole foods, fruit, vegetables and fish, and those who ate a mainly processed food diet, such as sweetened desserts, fried food, processed meat, refined grains and high-fat dairy products.
Researchers also accounted for education, physical activity, smoking, age, gender and chronic diseases. When the numbers were crunched it was found that participants who had a dietary pattern of largely processed foods had a 58 per cent higher risk of depression. People whose intake of whole foods was the highest had a 26 per cent lower risk of future depression than those who ate the least whole foods.
Big studies like this provide a stark reminder of the importance of diet to our mental health and general wellbeing. Exactly why some foods seem to protect us from, or actually promote depression, isn't fully understood. The effects of diet upon mental health are clear however, and this is an important message.
Akbaraly, T.N., Brunner. E.J., Ferrie .J.E., Marmot .M.G., Kivimaki. M., Singh-Manoux. A. (2009) Dietary pattern and depressive symptoms in middle age The British Journal of Psychiatry 195: 408-413.