Dietary Omega-6 Increases Risk of Depression
Bottomline: A large 10-year follow-up study shows that omega-6 fatty acids in the American diet significantly increase the risk of depression in men. Prog Neuro-Psychopharmacol Biol Psychiatry (2009).
Background: A recent study spanning 60 countries and 250,000 people indicated that depression produces the greatest decrement in health compared with the chronic diseases of angina, arthritis, asthma, and diabetes. Depression strikes 17 million Americans per year, more than cancer and heart disease, combined.
In the past century, there has been a dramatic rise in the consumption of polyunsaturated omega-6 fatty acids, predominantly from vegetable oils, at the expense of omega-3 fatty acids. Linoleic acid is the most commonly eaten omega-6 polyunsaturated fat in westernized countries.
Earlier studies indicate that depressed patients have: higher omega-6 fatty acids in their tissues and elevated proinflammatory omega-6 compounds such as thromboxanes, leukotrienes and cytokines.
Study:The association between severe depressed mood and dietary fatty acids were assessed among nearly 5000 adults aged 25–74 years who were examined in 1971–1975 as a part of a the National Health and Nutrition Examination Survey Epidemiology (NHES). The subjects in this study had an average of 10.6 years of follow-up.
Depression was assessed using the Center for Epidemiologic Studies Depression Scale questionnaire. Dietary fatty acid intake was evaluated using a 24-hour recall method, administered by dietitians, who also used food models to help the subjects assess their portions of food eaten.
Findings: There was a dose–response association between linoleic acid (omega-6) intake and depression among men. Men in the highest tertile group of linoleic intake (averaging 19 grams of dietary linoleic acid/day) had twice the risk being depressed compared to those in lowest third intake group, who ate on average 3.5 grams of linoleic acid/day. Notably, these risk estimates were adjusted for fish consumption.
Oleic fatty acid (the chief fatty acid in olive oil) was associated with a decreased risk of depression among women in a dose–response relationship. The authors concluded that a higher intake of oleic fatty acid reduced the risk of depression among women while increased intake of linoleic acid increased the risk of severe depressed mood among men.
Study quote: "The current study provides strong evidence that diets rich in omega-6 fatty acids may enhance the risk of depression among general population".
Comment: Experimental studies show that eicosapentaenoic acid (EPA), the omega-3 fat associated with mood improvement, is reduced in the cells, as a consequence of eating a diet high in omega-6 fat. (See High Omega-6 Diet Lowers Omega-3 Status, but Low Omega-6 Diet Preserves)
To get an idea of the linoleic acid content in food check out the Omega-6 Fat Tracker widget: How Much Omega-6 in Vegetable Oils? The Omega-6 Fat Tracker Widget
While the results from this study were different for men and women, the findings still fit with the benefits of eating a classic Mediterranean diet,which is low in omega-6 fat and rich in omega-9 fat (olive oil)--for more details see:
Link to Study:
Background: A recent study spanning 60 countries and 250,000 people indicated that depression produces the greatest decrement in health compared with the chronic diseases of angina, arthritis, asthma, and diabetes. Depression strikes 17 million Americans per year, more than cancer and heart disease, combined.
In the past century, there has been a dramatic rise in the consumption of polyunsaturated omega-6 fatty acids, predominantly from vegetable oils, at the expense of omega-3 fatty acids. Linoleic acid is the most commonly eaten omega-6 polyunsaturated fat in westernized countries.
Earlier studies indicate that depressed patients have: higher omega-6 fatty acids in their tissues and elevated proinflammatory omega-6 compounds such as thromboxanes, leukotrienes and cytokines.
Study:The association between severe depressed mood and dietary fatty acids were assessed among nearly 5000 adults aged 25–74 years who were examined in 1971–1975 as a part of a the National Health and Nutrition Examination Survey Epidemiology (NHES). The subjects in this study had an average of 10.6 years of follow-up.
Depression was assessed using the Center for Epidemiologic Studies Depression Scale questionnaire. Dietary fatty acid intake was evaluated using a 24-hour recall method, administered by dietitians, who also used food models to help the subjects assess their portions of food eaten.
Findings: There was a dose–response association between linoleic acid (omega-6) intake and depression among men. Men in the highest tertile group of linoleic intake (averaging 19 grams of dietary linoleic acid/day) had twice the risk being depressed compared to those in lowest third intake group, who ate on average 3.5 grams of linoleic acid/day. Notably, these risk estimates were adjusted for fish consumption.
Oleic fatty acid (the chief fatty acid in olive oil) was associated with a decreased risk of depression among women in a dose–response relationship. The authors concluded that a higher intake of oleic fatty acid reduced the risk of depression among women while increased intake of linoleic acid increased the risk of severe depressed mood among men.
Study quote: "The current study provides strong evidence that diets rich in omega-6 fatty acids may enhance the risk of depression among general population".
Comment: Experimental studies show that eicosapentaenoic acid (EPA), the omega-3 fat associated with mood improvement, is reduced in the cells, as a consequence of eating a diet high in omega-6 fat. (See High Omega-6 Diet Lowers Omega-3 Status, but Low Omega-6 Diet Preserves)
To get an idea of the linoleic acid content in food check out the Omega-6 Fat Tracker widget: How Much Omega-6 in Vegetable Oils? The Omega-6 Fat Tracker Widget
Link to Study:
Wolfe AR, Ogbonna EM, Lim S, Li Y, Zhang J.
Dietary linoleic and oleic fatty acids in relation to severe depressed mood: 10 years follow-up of a national cohort.
Prog Neuropsychopharmacol Biol Psychiatry. 2009 May 6. doi:10.1016/j.pnpbp.2009.05.002
Posted by Evelyn Tribole MSRD at July 11, 2009 10:15 AM 
Categories: EPA,Depression,Linoleic Acid,Diet,Brain,mood,2009 Studies,Omega-6 Fat,Abstract
Categories: EPA,Depression,Linoleic Acid,Diet,Brain,mood,2009 Studies,Omega-6 Fat,Abstract
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