Fighting Depression and Improving Cognition with Omega-3 Fatty Acids
By Laurie Barclay, MD
Benefits of Omega-3s in Pregnancy
At the other end of the age spectrum, eating seafood during pregnancy is linked to better neurodevelopmental outcomes in childhood. To some extent, these findings were unexpected, given concerns about potential harm to the baby from the mercury content in some fish. Researchers evaluated data from 11,875 pregnant women taking part in the Avon Longitudinal Study of Parents and Children.19
Surprisingly, women who followed their doctor’s recommendation to limit their seafood intake during pregnancy to 340 grams weekly had a 48% greater risk that their children would be in the lowest quarter of verbal IQ scores, compared with mothers who ate more than 340 grams of fish weekly. Mothers who ate less seafood also had a greater risk that their children would have problems with social behavior, motor skills, communication, and social development.
Translating these findings to clinical studies, researchers at the University of Western Australia randomly assigned 98 pregnant women to receive either high-dose fish oil (2200 mg DHA plus 1100 mg EPA daily) or placebo (olive oil) from 20 weeks of pregnancy until delivery. Neither the women nor the scientists knew which women were assigned to fish oil until the study was complete.20
Although children in both groups had similar growth rates at 2.5 years of age, those whose mothers received fish oil during pregnancy had significantly better eye-hand coordination.
The benefits of omega-3 also extend to infants born prematurely. They have been found to have decreased levels of DHA in brain cortex. Both preterm and term infants fed DHA have enhanced cortical visual acuity and cognitive outcomes.21 In fact, some infant formulas are now enriched with omega-3 fatty acids in response to recommendations that pregnant and nursing women maintain an adequate dietary intake of DHA to meet their own increased needs as well as those of the fetus or infant.22
How Much is Enough?
America’s obsession with thinness over the past three decades has led us to spurn all dietary fats, including beneficial omega-3 fatty acids such as EPA and DHA. The result has been a tidal wave of depression, attention-deficit/hyperactivity disorder (ADHD), and other psychiatric diagnoses.23,24 The incidence of depression has climbed higher with each decade of the twentieth century, as have health care costs for antidepressant medications and other mental health treatment.25
In North America today, the average daily intake of EPA plus DHA is only 130 mg, falling far short of the daily 1000-2000 mg total omega-3 fatty acids recommended by some clinicians for optimal health, mood, and cognitive function. Based on clinical trials, dosages of 1000-4000 mg may offer maximal benefits for those with depressed mood.26
“Although the precise mechanism of action is still unknown, accumulating evidence suggests that 1000-2000 mg daily of EPA may be useful in the treatment of mild to moderate depression,” Dr. Yamina Osher, lead author of a recent review of 12 clinical trials of PUFAs in depression, bipolar disorder, and other mood disorders27 and a member of the Faculty of Health Sciences at Ben Gurion University in Beer Sheva, Israel, tells Life Extension.
Researchers are currently investigating whether a diet deficient in omega-3 essential fatty acids increases the risk for depression, aggression, and suicide associated with alcoholism. Scientists are comparing the effect of omega-3 fatty acids with that of placebo in aggressive alcoholics, women with depression during pregnancy, and suicide attempters.
Additional therapeutic benefits are being explored, including the use of omega-3 in attention deficit disorder and in autism, but there is still insufficient evidence on which to base firm conclusions.
Other recent research reviews have noted the need for well-controlled clinical trials.28-32
Implications for Treatment
Despite this unfinished picture, the Committee on Research on Psychiatric Treatments of the American Psychiatric Association invited scientists to participate in the Omega-3 Fatty Acids Subcommittee. This expert panel convened in 2006 to review published studies and those presented at scientific meetings that evaluated the effect of omega-3 fatty acids in major depressive disorder, bipolar disorder, schizophrenia, dementia, borderline personality disorder and impulsivity, and ADHD.
Their conclusions, which were approved by three separate committees of the American Psychiatric Association, declared that population-based studies and tissue studies support a protective effect of omega-3 essential fatty acid intake, particularly EPA and DHA, in mood disorders. A review of the randomized controlled trials showed negligible risks and a statistically significant benefit of omega-3 fatty acids in both major depression and in bipolar depression, with less evidence of benefit in schizophrenia.33,34
“The evidence suggests that omega-3 fatty acids are important for optimal human health and brain function,” Marlene P. Freeman, MD, lead author of the American Psychiatric Association review, tells Life Extension. “In some studies, investigators have demonstrated a beneficial effect of omega-3 fatty acids on mood disorders, and more research is underway. Individuals with serious mental health disorders should always receive a full evaluation and know their treatment options.”
“As professionals, we encourage anyone with depression or other disorders to get the medical attention that they deserve,” says Dr. Freeman, who is also Director of the Women’s Mental Health Program and Associate Professor of Psychiatry, Obstetrics and Gynecology, and Nutritional Sciences at the University of Arizona’s College of Medicine. She concludes, “Omega-3 fatty acids may be an important part of the treatment of some psychiatric disorders, and at this time researchers are figuring out where they fit in to treatment. They may be an effective treatment for some individuals, with important medical benefits.”
Omega-3 fatty acids from fish oil may have anti-thrombotic effects. Individuals who have bleeding disorders and those taking warfarin (Coumadin®) should only use fish oil in consultation with a physician.35
Essential for healthy brain structure and function, omega-3 fatty acids may be critical for maintaining healthy mood and keeping mental distress at bay. These powerful fatty acids are essential throughout life—helping ensure healthy brain development in infants, maintaining a healthy mood in adulthood, and protecting the aging brain against cognitive decline and dementia. Optimizing your intake of omega-3 fatty acids is not only essential for a healthy body, but also for a healthy mind.
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