An interesting study from London, England shows that people with schizophrenia have an abnormal ratio of fatty acids in their cell membranes and giving them omega-3 fatty acids corrects both their schizophrenia and membrane abnormalities (1).
Depression may be caused by omega-3 deficiency that results from not eating enough nuts, whole grains, beans and other seeds, and seafood (2). Many psychiatrists treat depression with drugs that raise brain levels of serotonin. A diet deficient in omega-3 fatty acids may lower brain levels of serotonin and cause depression. Depression is associated with low levels of red blood cell membrane and low intake of omega-3 fatty acids (3), and a high ratio of omega-6 to omega-3 fatty acids is associated with depression (4,5).
Depression is 60 times more common in New Zealand (6 percent) than in Japan (.12 percent), where the Japanese eat far more omega-3s in their fish (6). Pregnancy uses up omega-3s which may be the primary cause of post-partum depression. Women with the low blood levels of omega-3s are at increased risk for post-partum depression.
Depression increases a person’s chances of getting a heart attack. Depressed people often have low blood levels of omega-3s and so do people who are likely to suffer heart attacks (6). The association of depression and schizophrenia with heart attacks may be explained by both being caused by low omega-fatty acid levels. If these studies can be supported by further studies, some cases of depression may be prevented and treated by eating large amounts of deep-water fish, nuts, beans, whole grains and other seeds.
Fats are classified into primarily saturated and primarily polyunsaturated fats. Fresh polyunsaturated fats are good because they help to lower cholesterol and prevent heart attacks. Polyunsaturated fats are further classified by their chemical structure into omega-3 and omega-6 fatty acids. You need both omega-3s and omega-6s to be healthy, but they have different functions in your body. You may have heard that you need to eat deep-water fish oils to get omega-3s but this is not true. You get omega-3s from plankton or anything that eats plankton in the ocean; and from many different seeds, including nuts, beans and whole grains.
Some seeds, such as walnuts and flaxseeds, are particularly rich sources of omega-3s, but you don’t need to eat them if you eat plenty of seeds that contain smaller amounts, such as whole grains and beans. To prevent flour from spoiling, the miller removes the germ which contains almost all the omega-3 fatty acids before he grinds it into flour. Therefore you may lack adequate amounts of omega-3 fatty acids if you eat bakery and pasta products and do not eat other sources of omega-3s:deep-water fish and seeds.
More on omega-3s
1) BK Puri, AJ Richardson, DF Horrobin, T Easton, N Saeed, A Oatridge, JV Hajnal, GM Bydder. Eicosapentaenoic acid treatment in schizophrenia associated with symptom remission, normalisation of blood fatty acids, reduced neuronal membrane phospholipid turnover and structural brain changes. International Journal of Clinical Practice, 2000, Vol 54, Iss 1, pp 57-63.
2) C B. Nemeroff, D Musselman, MD. Emory. Archives of General Psychiatry April, 1999.; 56:381.
3) Edwards R, Peet M, Shay J, Horrobin D. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord. 1998;48:149-155.
4) Adams PB, Lawson S, Sanigorski A, Sinclair AJ. Arachidonic acid to eicosapentaenoic acid ratio in blood correlates positively with clinical symptoms of depression. Lipids. 1996;31:S-157-161.
5) Maes M, Smith R, Christophe A, Cosyns P, Desnyder R, Meltzer H. Fatty acid composition in major depression: decreased omega 3 fractions in cholesteryl esters and increased C20:4 omega-6/C20:5 omega-3 ratio in cholesteryl esters and phospholipids. J Affect Disord. 1996;38:35-46.
6) Musselman DL, Evans DL, Nemeroff CB. The relationship of depression to cardiovascular disease: epidemiology, biology, and treatment. Arch Gen Psychiatry. 1998;55:580-592.