Processed Foods Found to Affect Mental Health

by | Jul 27, 2011 | 2009, Brain Health, Depression, Processed Foods, Whole Foods - General

Written by Greg Arnold, DC, CSCS. In a 5-year study of 3,486 participants, those who had the highest 20% of whole foods intake had a 26% reduced risk of depression while those in the highest 20% of processed food intake had a 58% increased risk of depression. 

Major depressive disorder is the leading cause of disability in the U.S. for ages 15-44 (1), affecting nearly 15 million American adults each year, which is nearly 7 percent of the U.S. population aged 18 and older (2).  Major depressive disorder is a significant contributor to the $83 billion cost of depression to our healthcare system each year (3).  A large scale study (4) has found that processed foods, known to increase prostate cancer risk (5), may also increase risk for depression.

In the study, 3,486 patients with an average age of 55.6 years who participated in the Whitehall II study (6) provided dietary information of 127 foods that were divided into 37 groups (7) with a special emphasis on either ‘whole foods’ (heavily loaded by vegetables, fruits and fish) and ‘processed foods’ (heavily loaded by sweetened desserts, fried food, processed meat, refined grains and high-fat dairy products).   The patients were then followed up over an average span of 5 years and completed a depression questionnaire called the CES-D (8).

After the 5 years of follow-up, researchers found that those in the highest 20% of whole foods intake had a 26% reduced risk of depression as depicted in the CES-D scale.    In contrast, those in the highest 20% of processed food intake was associated with a 58% increased risk of depression from the CES-D scale.  While the researchers cited high antioxidant intake (9), folic acid intake (10), and fish consumption (11), all of which were characteristics of the ‘whole food’ diet, to probably play a role in reducing depression risk, they cited the role of processed food in depression as “a novel finding”.  For the processed food diet they put the onus on increased sugar intake (12) and resulting inflammation (13) as contributing to increased depression risk.

For the researchers, “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.”

Source: Akbaraly, Tasnime N., Eric J. Brunner, Jane E. Ferrie, Michael G. Marmot, Mika Kivimaki, and Archana Singh-Manoux. “Dietary pattern and depressive symptoms in middle age.” The British Journal of Psychiatry 195, no. 5 (2009): 408-413.

© 2009 Royal College of Psychiatrists

Posted July 27, 2011.

Reference:

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