Standard American diet promotes depression via fatty acid imbalance
To date, few clinical studies have tested the antidepressant value of omega-3s, and they've produced mixed results.
While we await the results of future clinical research, a new animal study suggests a reason for the mixed results ... excessive intake of omega-6 fats.
The standard American diet is overloaded with omega-6 fats from the cheap vegetable oils used in most home kitchens and most prepared foods (corn, soy, sunflower, safflower, and cottonseed).
Omega-6 excess seen in sad rats... and average American diet
Tel Aviv University researchers recently compared the brains of rats genetically "programmed” to experience chronic depression with brains of normal rats.
To their surprise, they found that the chief distinction between the two lay in the brain levels of omega-6 fatty acids.
They'd expected that the depressed rats would have lower levels of omega-3s, but that was not the case.
Instead, the brains of the depressed rats higher levels of arachidonic acid, an omega-6 fat the body makes from the omega-6 fats in plant foods and vegetable oils.
Lead researcher Dr. Pnina Green noted that prior animal studies indicate that increased omega-3 intake may reduce brain levels of omega-6 arachidonic acid, which could account for the anti-depression effects of omega-3 fats.
- Green P, Gispan-Herman I, Yadid G. Increased arachidonic acid concentration in the brain of Flinders Sensitive Line rats, an animal model of depression. J Lipid Res. 2005 Jun;46(6):1093-6. Epub 2005 Apr 1.
- Alessandri JM, Guesnet P, Vancassel S, Astorg P, Denis I, Langelier B, Aid S, Poumes-Ballihaut C, Champeil-Potokar G, Lavialle M. Polyunsaturated fatty acids in the central nervous system: evolution of concepts and nutritional implications throughout life. Reprod Nutr Dev. 2004 Nov-Dec;44(6):509-38.
- Horrocks LA, Farooqui AA. Docosahexaenoic acid in the diet: its importance in maintenance and restoration of neural membrane function. Prostaglandins Leukot Essent Fatty Acids. 2004 Apr;70(4):361-72. Review.