NEW YORK (Reuters Health) – Fish oil pills and B vitamins may not help ward off depression after a heart attack or stroke, a new clinical trial finds.
In fact, men who were randomly assigned to take fish oil actually ended up with an increased risk of depression symptoms.
It’s not clear whether the fish oil is to blame. For now, however, the researchers say there’s no evidence to support using fish oil or B vitamins to ward off depression. What’s more, it’s not clear if people with cardiovascular disease should routinely use the supplements for any reason.
Studies have found that people who suffer depression after a heart attack or stroke tend to fare worse than their non-depressed counterparts. It’s not clear why that is, but the findings have sparked interest in finding ways to prevent depression in heart disease and stroke survivors.
Fish oil has seemed like a good candidate because it’s rich in omega-3 fatty acids, which are thought to be good for the heart — and possibly for mental well-being. Similarly, B vitamins could be helpful, in theory. Deficiency in folate, for instance, has been linked to a decline in serotonin.
But in the new study, Dr. Valentina A. Andreeva of the University of Paris and colleagues found that giving patients supplements — of B vitamins, fish oil or both — did nothing to prevent depression symptoms over nearly five years.
As reported online May 30th in the American Journal of Clinical Nutrition, the research team randomly assigned 2,000 middle-aged and older adults who’d suffered a heart attack, stroke or angina to receive either a mix of folate and vitamins B6 and B12 each day; fish oil capsules; fish oil and B vitamins; or placebo capsules.
Over the next three to five years, almost one-third of the study group had some degree of depression symptoms. And about 7% had moderate to severe depression.
There was no evidence that the risk was any lower for people who’d been on B vitamins or fish oil, versus the placebo group. But among men, those on fish oil were 28% more likely to develop some level of depression symptoms.
It’s not clear what to make of that, the researchers say. They point to another recent clinical trial that tested fish oil for preventing depression in older adults. And while those researchers found no benefits, they also found no increased risks.
For now, there appears to be no reason for people with a history of heart disease or stroke to routinely use fish oil or B vitamins.
Dr. Andreeva said that in earlier reports on this same study group, the researchers found that neither supplement cut the risk of future heart problems or stroke. Nor was there any evidence the supplements curbed cancer risk.
And a recent meta-analysis of 14 past studies reached similar conclusions: There’s no clear evidence that fish oil prevents heart attacks or strokes in people with existing heart disease.
That does not, however, mean people shouldn’t eat fish. In fact, the American Heart Association and other groups recommend that people eat fish at least twice a week — preferably fattier varieties, like salmon and tuna, that contain more omega-3.
Am J Clin Nutr 2012.