Feature Archive

Fish Oil to Treat Depression?

Omega-3's may have an affect on serotonin levels.

WebMD Feature Dave thinks a lot about fish these days. Study after study has suggested benefits for omega-3 fatty acids, which are plentiful in certain fish oils. But what intrigues Dave isn't that omega-3's might reduce his risk of heart attack, or ease the pain of arthritis. He's hoping to lubricate his mind.

A handful of small studies have suggested that omega-3 fatty acids can help smooth out the mood swings of bipolar disorder. There are few effective treatments against the disease, so the news is a hot topic now at support groups for manic-depressives, like the Berkeley, CA, group in which Dave participates.

The first news to attract attention was a 1998 report in the Journal of Affective Disorders. Researchers noted significantly lower levels of omega-3's in the red blood cell membranes of patients with depression.

Then in the May 1999 Archives of General Psychiatry, Andrew Stoll, M.D., and colleagues reported a study of fish oil in 30 manic-depressive patients. Sixty-four percent of those who took 10 grams of fish oil per day for four months reported a marked improvement in their symptoms. By contrast, only 19 percent of those receiving the placebo benefited.

Cell Softeners?

These studies aren't the only research that points to the benefits of fish oil for mood problems. "There are a lot of reasons to believe it works," says Stoll. "In countries where the average fish consumption is high we see lower rates of depression."

On the biochemical front, researchers point out that cell membranes are made up partly of omega-3's. It is possible that increasing the omega-3 levels makes it easier for serotonin -- a chemical that carries messages from one brain cell to another -- to pass through cell membranes. "Research still needs to be done on the exact mechanisms involved," Stoll notes, "but we do know that omega-3 does affect the membranes and changes functioning." And increasing omega-3 "has direct effects on serotonin levels."

Diet and Depression

Joseph Hibbeln, M.D., a psychiatrist at the National Institute of Health, thinks omega-3's might explain why the rate of depression is rising in the United States.

In a health-conscious push to rid our diets of saturated fats and cholesterol, Americans have been eating less red meat and eggs -- two good sources of omega-3's. Furthermore, we have been switching to the polyunsaturated fats, such as corn, soybean, and sunflower oils, which are relatively low in omega-3's.

Supplement or Go Fish

But just how to mend that situation remains controversial. Omega-3's might worsen some chronic illnesses. (Check with a doctor if you have such a condition before starting to take supplements.) The Food and Drug Administration is now considering what quantity of omega-3's to recommend; currently it has no recommendation but classifies three grams per day as "safe."

Though Stoll gave patients 10 grams of fish oil a day for his study, he advises starting with lower doses. He believes that packaged fish oil supplements are the easiest -- and possibly safest -- way to increase omega-3 levels.

"Unfortunately in our country eating too much fresh fish is potentially dangerous because of possible mercury and pesticide levels," he explains. "Farm-raised fish is perhaps safer, but depending on what they are fed, the fish may not have the needed quantity of omega-3's."

But concerns have also been raised about the levels of contamination in fish oil supplements. Regulators do not currently test the purity of supplements.

Hibbeln cautions that people should not take cod liver oil in the quantity necessary to get three grams per day of omega-3's because that much cod liver oil would contain dangerous levels of vitamin A.

On the other hand, flaxseed oil is a good source of omega-3's. It can be taken as a supplement or used in salad dressings. Unlike fish oils, which contain a different combination of omega-3's, flaxseed oil should not be cooked because heat can destroy the omega-3's.

More answers are expected soon. The National Institute of Mental Health's Center for Complementary and Alternate Medicine is sponsoring Stoll in a large new study, one of three now under way. All three are expected to be complete by the end of next year.

But Dave probably won't wait for the results. "Looks like I need to go out and get myself some fish oil," he says.

©1996-2005 WebMD Inc. All rights reserved.
Last Editorial Review: 1/30/2005 10:41:28 PM



STAY INFORMED

Get the Latest health and medical information delivered direct to your inbox!