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Prozac of the Deep

Fish Oils for Depression and Manic-Depression

For years, scientists had wondered why Greenland Eskimos had such a low incidence of heart disease, despite a diet of seal blubber and other high-fat foods. Studies eventually revealed the reason: They eat a lot of fish rich in compounds called
omega-3 fatty acids, a "good" fat with cardioprotective effects. Now, compelling new evidence suggests these fish oils may be providing another benefit as well--keeping the Eskimos "even keeled" and happy.

In a study from Harvard Medical School, assistant professor of psychiatry Dr. Andrew Stoll and colleagues at McLean Hospital in Boston found that the omega-3s in salmon, mackerel, tuna, sardines, and other deep sea, cold-water fish may have a profound effect on mood. In the study (Archives of General Psychiatry, 5/99), 30 patients with manic depression--also called bipolar disorder--received either fish oil or olive oil (as a placebo) along with their standard medications, including lithium and Depakote. After four months, 65% of the fish oil recipients improved, compared with only 19% of the olive oil group. The results were so impressive that the researchers halted the study early so that those in the placebo group could begin taking fish oil if they wished.

No one knows exactly how omega-3s regulate mood. One theory is that they work like lithium and certain other standard drugs by dampening overactive nerve-to-nerve communication channels in the brain. "We know that omega-3s have this effect in other parts of the body, so we assume that it happens in the brain as well," says Dr. Stoll. "The other theory is that we are simply replacing what's missing in the American diet," he says. Indeed, research by Joseph Hibbeln at the National Institute on Alcohol Abuse and Alcoholism suggests that the increase in the number of people suffering from depression in the United States over the past few decades may be directly linked to the declining consumption of fish over the same time period.

"Omega-3s, which are lacking in diets in the U.S. and other developed countries, are very abundant fats in the brain and are essential for normal brain function," says Dr. Stoll. "It's likely that they are involved in a range of disorders in addition to manic depression, including major depression and schizophrenia."

A safe, natural mood stabilizer
Dr. Stoll is beginning a more rigorous manic depression study, and trials of omega-3s for other forms of depression are under way. Still, he finds the data promising enough to recommend omega-3s to many of his own patients with
depression or manic depression. "If omega-3s were a toxic substance, I wouldn't use them on the basis of preliminary data, although the data were strong. But because they are safe and because they may work, we use them as an adjunct, adding them to other medications people are using," he says.

"In mild cases we sometimes go with omega-3s first because you have very little to lose and everything to gain," says Dr. Stoll. "If the person doesn't respond to omega-3s, you can move on to conventional treatments." He cautions, however, that anyone with depression or manic depression should first see a doctor. "It's not that the therapy is dangerous, but the conditions are dangerous and need professional intervention," he says.

Unlike Prozac and other antidepressants that can cause sexual problems and other troubling side effects, fish oils appear to cause nothing more serious than occasional indigestion. They are also compatible with most prescription medications, although those taking blood-thinning drugs or herbs, such as Coumadin, aspirin, or ginkgo biloba, should watch out for excessive bleeding since, in theory at least, fish oils may have an anticoagulant effect.

Suggested dose:
For mood disorders, Dr. Stoll recommends 3 to 10 grams daily of the two omega-3 fatty acids found in fish oils--EPA and DHA--under the supervision of your doctor. Divide into three doses, and take with food.

Cod liver oil is not an appropriate source of omega-3s. "The amount you'd have to take to supply a therapeutic dose of omega-3s provides a toxic dose of vitamin A," warns Dr. Stoll.

Buying fish oils: the ABCs of omega-3s

Omega-3s, a "good" type of polyunsaturated fat, are essential nutrients for the brain and other tissues. Numerous studies indicate that they may protect against heart disease and inflammatory conditions such as psoriasis and rheumatoid arthritis. And new research suggests that fish oils may be a safe, natural way to relieve depression. But while eating fish once or twice a week may supply enough omega-3s to lower your risk of heart disease, higher doses are probably needed to fight mood disorders.

Fish oils contain two kinds of omega-3s--EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). A third type, called alpha-linolenic acid, comes from flaxseed oil, walnuts, and a few other plants, including plankton (which fish eat and convert to EPA and DHA). Alpha-linolenic acid may also have mood-stabilizing effects, but unlike EPA and DHA it has not yet been tested for this purpose.

To fight depression and manic depression, research indicates that you need 3 to 10 grams daily of fish-oil omega-3s--or EPA plus DHA. A fish oil supplement is your best bet, but read the label carefully. Serving sizes, capsule sizes, and concentrations vary widely from one brand to the next, as does the proportion of EPA to DHA.

For example, a 1-gram fish oil capsule may contain, say, 180 mg of EPA and 120 mg of DHA. To get the total omega-3s, add these two together (don't worry about the relative proportions). One capsule thus supplies 300 mg total omega-3s. You would need 10 capsules to get a 3 gram (3,000 mg) dose, and 20 for a 6 gram dose. There are other ways to get a high dose of omega-3s (see below), but clearly, fish oil capsules are the most economical and convenient.

For 6 grams a day of EPA plus DHA omega-3s, you would need:

Source Daily Dose Daily Cost
CONCENTRATED FISH OIL SUPPLEMENTS (e.g., Twinlab's TwinEPA Extra Strength, Solgar's Omega-3 700) 7 to 9 softgels $2.51
REGULAR-STRENGTH FISH OIL SUPPLEMENTS (e.g., Nature's Way Max EPA) 15 to 20 softgels $2.09 FISH OIL SUPPLEMENTS IN LIQUID FORM 3 tablespoons $2.32
TUNA, CANNED Four 6-1/2 oz. cans $4.76
TUNA, FRESH Two 7-oz. fillets $11.33
SARDINES Four 3-1/2 oz. tins $8.36
SALMON Two 8-oz. steaks $6.99
SWORDFISH Three 8-oz. steaks $17.92
HALIBUT Six 8-oz. steaks $26.85
CAVIAR, ALL TYPES 4 oz. $16.36 to $160.00

Date Published: 10/23/2000
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