Omega-3 is an essential fatty acid that promotes cardiovascular health. High levels of the bad cholesterol -- low-density lipoproteins and triglycerides -- and low levels of the good cholesterol high-density lipoproteins can lead to cardiovascular disease. Omega-3 can help lower the blood content of the bad cholesterol and raise the good cholesterol. More recently, omega-3 has received attention for its possible positive effects on mood-disorders such as major depression, generalized anxiety disorder, panic disorder and bipolar disorder.
Omega-3 Fatty Acids
Omega-3 is found in high amounts in salmon, tuna, sardines, wild game and walnuts. The fat is "essential" because it must be supplied through the food, as the body cannot synthesize it. The other essential fatty acid is omega-6, found in corn, dairy products and soybean oil. Omega-3 and omega-6 have complementary functions. Omega-3 decreases inflammation and is an important component of cell membranes and nerve synapses. Omega-6 increases inflammation when there are foreign invaders in the body.
Omega-3 and Depression
As reported in Science Daily, a 2001 study completed in Finland showed that infrequent consumption of fish and depression were significantly correlated. A Dutch study published in 2003 showed that people who were depressed and those without depression had significantly different intakes of omega-3 fatty acids. In a newer study published in the June 2010 issue of "Journal of Clinical Psychiatry," it was found that omega-3 supplements were as efficient as conventional antidepressant medications in the treatment of major depression.
Serotonin in Anxiety and Depression
According to Joseph R. Hibbeln from the National Institute on Alcohol Abuse and Alcoholism, omega-3 can affect the functionality of the neurotransmitter serotonin, which plays a critical role in both depression and anxiety. Depression and anxiety have similar chemical profiles. Both disorders are characterized by low brain levels of serotonin. The most widely used antidepressant drugs, selective serotonin re-intake inhibitors, or SSRIs, work by slowing the speed with which serotonin outside the neurons is broken down and re-absorbed into the cells. These drugs are also commonly prescribed for anxiety disorders. If omega-3 fatty acids can help prevent depression by increasing the functionality of serotonin, it can also help prevent anxiety.
The 2011 study of the lack of dietary omega-3 suggests that it may help prevent mood disorders. Omega-3 is essential to the optimal function of two brain regions involved in motivation and emotional regulation -- the prefrontal cortex and the nucleus accumbens. As a lack of motivation is more significant in depression than in anxiety, suggesting that omega-3 may have a greater positive effect on depression than anxiety.