The Evolving Omega-3 Fatty Acid Story: The Icing on the Cake (And Why It Shouldn’t Be Eaten)
Omega-3 fatty acids are important for brain development and function and are essential to the human diet since they cannot be synthesized by the body. Omega-3 fatty acids are derived from canola oil, walnuts, flax seed oil, leafy vegetables, and especially fish. The main omega-3 fatty acids include eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). They have anti-inflammatory effects, unlike omega-6 fatty acids, which are pro-inflammatory. The omega-6 fatty acids come from soy, peanuts, corn oil, and meats, and are associated with increases in obesity, myocardial infarction, and stroke.
In a recent review of the literature, John Davis and Joe Hiblen found that diets that include high levels of omega-3 fatty acids are associated with decreased incidence of depression, suicide, and cardiovascular disease. The researchers performed a meta-analysis of all the prospective depression treatment studies of omega-3 fatty acids compared to placebo. They found that EPA had antidepressant effects in humans, with moderate effect size and a high degree of statistical significance. DHA, however, did not appear to have an antidepressant effect, and pure DHA was even associated with some worsening of depression.
Editor’s note: This meta-analysis helps clarify some of the ambiguities in the literature about the antidepressant efficacy of the omega-3 fatty acids, clarifying that EPA alone is an effective antidepressant. The one study that did not find antidepressant effects with EPA was carried out by the Bipolar Collaborative Network, in which I am an investigator. Our study, published in an article by Keck et al., showed that 6g of EPA was not significantly more effective than placebo in bipolar depression or in rapid cyclers. However, there is some indication that 6g may be too high a dose of EPA, and most of the recommendations now suggest using 1-2g of either EPA or an EPA/DHA combination. Read more
Ketamine Infusions May Help in Suicidal Emergencies
Intravenous ketamine has consistently been found to bring about almost immediate antidepressant effects (usually within two or three hours), which can last three to five days in duration. Typical doses are 0.5 mg/kg IV infusion over 40 minutes. A new abstract presented at the meeting of the American College of Emergency Physicians in 2010 indicated that when patients received 0.2 mg/kg ketamine infused over a period of 1-2 minutes, suicidal ideation decreased within 40 minutes. Fourteen of 15 subjects were no longer suicidal after the infusion, and in 13 of those 14 the improvement was sustained at follow-up ten days later.
Editor’s note: Such rapidly occurring, robust antidepressant/antisuicidal effects from IV ketamine continue to suggest that it is useful for emergency room therapeutic maneuvers.
Early Life Stressors Linked to Persistent Inflammation and Endocrine Abnormalities
Epigenetics is a relatively new area of study that examines changes in DNA regulation and structure that can come about as a result of environmental events, as opposed to the genetic inheritance (DNA sequence) people receive through their parents’ genes. Epigenetic effects occur when an environmental stressor or chemical causes methyl or acetyl groups to attach to DNA or to histones (around which DNA are wound). These epigenetic changes determine how difficult it is to turn on genes coded in the DNA (see here for more information about the way the environment produces these epigenetic effects).
After the jump: Several studies presented at the 65th Annual Scientific Convention of the Society of Biological Psychiatry earlier this year suggested a link between environmental stress and both inflammation and abnormalities in DNA.
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