Heart disease continues to reign as the number one cause of death in the U.S. and for heart disease patients also suffering from depression, the chances for death are even greater. Researchers have documented that one characteristic both conditions share is low levels of omega 3 fatty acids. It would stand to reason then that the addition of an omega 3 supplement to the existing depression medicine regimen of these patients might yield a benefit—not so, according to a recently published study.
The randomized, placebo-controlled study, which was published in the October 21 issue of the Journal of the American Medical Association (JAMA October, 21 2009;302(15):1651-1657), set out to determine whether omega 3s could improve the response to sertraline (Zoloft) in 122 patients with both major depression and coronary heart disease.
Following a two-week run-in period during which all patients were given 50 mg/d of sertraline, 62 (59 by the time the study concluded) randomly selected patients received 2 g/d of omega 3 fatty acid ethyl esters (930 mg of eicosapentaenoic acid [EPA] and 750 mg of docosahexaenoic acid [DHA]). The 60 (56) remaining patients received corn oil placebo capsules. This dosing lasted 10 weeks.
At the conclusion of the trial, patients were evaluated using the Beck Depression Inventory and the Hamilton Rating Scale for Depression. Researchers were surprised to find no difference between the two groups when it came to the regression of their depression.
Lead study author Robert Carney, PhD, professor of psychiatry and director of the Behavioral Medicine Center at Washington University School of Medicine’s Department of Psychiatry in St. Louis, MO, said he was “very surprised” that the results of the study were so disappointing. “Omega 3 blood levels and dietary intake are low in depressed patients,” he explained. “Smaller studies showed big effect on depression when added to standard antidepressant treatment. We thought omega 3 may help explain the relationship between depression and heart disease (depression is a risk factor for cardiac events).”
He added that in hindsight the results could have been attributed to several factors. “Possibly [the] dose was too low or the DHA/EPA ratio may not have been optimal,” he said. “[It’s] hard to judge based on this and other published studies.”
He and his colleagues also conjectured whether higher doses of sertraline, or a different ratio of EPA to DHA, longer treatment, or omega 3 monotherapy could improve depression in patients with coronary heart disease, but that remains to be determined.
“We have much to learn about the relationship between omega 3 and depression and heart disease,” he said. “More clinical trials should be undertaken, but it is also important to understand the mechanisms that may explain how omega 3 is related to depression.”
Despite this study’s less than favorable outcome, Dr. Carney and his colleagues continue to be intrigued with this area. “We are currently exploring our data more carefully to decide our next step,” he said, when asked what their next step might be.
For now though, he said, there isn’t enough evidence to warrant this type of treatment recommendation to people with or without heart disease.