by John Casey, Medical Writer
The link between omega-3
fatty acids and cardiovascular health is well documented. Less well known,
however, but perhaps equally as important, is new research showing that
persons with bipolar disorder, depression, even schizophrenia, may see
significant improvements in symptoms with increased omega-3 consumption.
"The research work is a
long way from complete," says Dr. Joseph R. Hibbeln, chief of the outpatient
clinic at the National Institute on Alcohol Abuse and Alcoholism at the
National Institutes of Health, who has done extensive research on omega-3
and mood disorders. "And if someone is severely depressed or has acute psychiatric
problems, that person should not change treatment, but that being said,
what we are finding out about omega-3 and the treatment of mood disorders
is really astonishing."
Surprisingly Positive Outcomes
Dr. Andrew Stoll, director of psychopharmacology at Mclean Hospital and an assistant professor of psychiatry at Harvard University, recently led a two-center trial on bipolar disorder and increased omega-3 consumption at Brigham and Women's Hospital in Boston and Baylor College of Medicine in Houston."The study was supposed to be 9 months long," says Dr. Stoll. "But the supply of the omega-3 compound we were using was suddenly and unexpectedly suspended just after we completed the first phase of the investigation. By then, we had enough data to see that the placebo patients were doing really horribly, and since we were going to run out of our supply of omega-3 anyway, we decided to stop the study early and give all the subjects the remaining supply."
The 4-month, double-blind, placebo-controlled trial compared omega-3 fatty acids to placebo, in addition to the subjects' usual treatment, in 30 patients with bipolar disorder. A Kaplan-Meier survival analysis for the subjects found that the omega-3 group had a significantly longer period of remission than the placebo group. In his findings, Dr. Stoll wrote that "fatty acids may inhibit neuronal signal transduction pathways in a manner similar to that of lithium carbonate and valporate, two effective treatments for bipolar disorder." In a larger study of 240 subjects with manic depression at the Stanley Foundation in Bethesda, Maryland, researchers are attempting to replicate Dr. Stoll and colleagues' findings.
|
How It Helps Stabilize Mood
Although the exact mechanism by which omega-3 stabilizes mood is unclear, researchers suspect that the compound works by increasing the amounts of essential fatty acids available in the synaptic membranes of the brain. When the synapses do not have enough docosahexaenoic acid (DHA), an important component of some omega-3s, levels of a key brain transmitter, serotonin, appear to be affected."We know that patients with low concentrations of serotonin are associated with a greatly increased risk of depression and suicide," says Dr. Jerry Cott, a psychopharmacologist at the National Institutes of Health, who recently completed a review of omega-3 research on mood disorders. "Omega-3 appears to play an absolutely crucial role in maintaining serotonin levels and mood stabilization."
Altered Diet, More Mood Disorder
"Archaeological dietary studies show that when we evolved as human beings, we had diets that were much higher in DHA-rich omega-3," says Dr. Hibbeln. "We ate more fish and game meat, and we used to eat organ meats and brains. In 100 years, we've eliminated a lot of these sources of omega-3 from our diets, and studies of the prevalence of depression show that it has increased about 100-fold over the same time period," says Dr. Hibbeln. Other, nonanimal sources of omega-3 include flax seed, pumpkin seed, and walnuts. Most omega-3 supplements are derived from several species of cold-water fish."Today, in our industrialized society, we get most of our fats from vegetable sources, such as corn and safflower," says Dr. Cott. "We eat oils rich in trans-fatty acids that are taken up more quickly than omega-3 and block omega-3 absorption. So not only do we eat less omega-3 in general, but the fats that we do eat tend to block it from getting to where we need it."
Although some biochemists have cast doubt on the efficacy of flax seed as a source of DHA-rich omega-3, studies show it has the same beneficial properties, without the fishy aftertaste of some fish-oil pills. "While flax seed is an omega-3, it has an 18-carbon chain, as opposed to the 20-carbon chain of DHA-containing omega-3 fish oils," says Dr. Hibbeln. "From a biochemistry standpoint, you'd think that flax seed would be an inefficient source of omega-3." But in studies with bipolar patients, Dr. Cott says, flax-seed oil appears to have an even faster effect than fish oil on mood stabilization. Some patients are reporting anxiety reduction within a half an hour of taking it," he says. "It's not supposed to be possible, but that's what we're seeing."
Although Dr. Stoll's omega-3 small study of 30 bipolar patients is the only such US study so far to have had its findings published in a peer-reviewed journal, several larger-scale studies are now underway here and in England to try to replicate Dr. Stoll's findings.
Where the Research Is Headed
More studies are going forward in several areas right now. In Sheffield, England, Dr. Malcolm Peete is directing a large-scale study looking at omega-3's ability to help control symptoms of schizophrenia.Here in the United States, Dr. Stoll and Dr. Lauren Marangell of Baylor University have two omega-3 studies in the works. "We got funding from that National Institutes of Health to do a larger follow-up study with 120 bipolar patients across a full year," says Dr. Stoll. "In the pilot study, we had only 30 patients, and they were all in different mood states and on varying medication or no medication. This study will be more controlled by having everyone in the same mood state and all on the same medications." Dr. Stoll also is conducting a study on omega-3 at Harvard University of 80 patients with regular, or unipolar, depression, who are not currently in treatment.
All of these findings are proving surprising, even to researchers in the field. "If these preliminary findings are replicated, then this is a remarkable discovery," says Dr. Cott. "We're seeing an efficacy with omega-3 that is equal to or better than current medications"
For more information
on the treatment of depression, bipolar disorder, and schizophrenia, visit
the National Institute of Mental Health at www.nimh.nih.gov
on the Web.
John Casey is a CBSHealthWatch staff member. He has written for Parade magazine and numerous online publications.
Reviewed for medical accuracy by a faculty physician, Beth Israel Deaconess Medical Center (BIDMC) and Harvard Medical School.