Health in the News - 23.Apr.01
Depression & Nourishing your Brain
'A spate of cross-national studies has also linked low fish consumption to high rates of major depression, bipolar disorder, postpartum depression and suicidal tendencies.'
It's no secret that the fats in fish and walnuts are good for your heart. New research suggests they may also ward off depression and mental maladies, as Newsweek reports
Psychiatrist Andrew Stoll has seen plenty of patients with bipolar disorder, but few more serious than a middle-aged man he calls "X."
Patient X suffered his first episode of mania in Rome, where he became so delusional that he landed first in jail and then in a psychiatric ward. Patient X escaped and was re-arrested, but by then the Italian authorities had had enough. They bundled him onto a plane back to Boston, where he was taken to Stoll's office at Brigham and Women's Hospital. Stoll tried all the usual medications. But lithium alone didn't work, and Patient X was unable to tolerate the side effects of strong antipsychotic drugs.
That's when Stoll, an assistant professor of psychiatry at Harvard, turned to a more unconventional remedy-he instructed Patient X to eat a quarter pound of salmon every day, while continuing to take his lithium. The treatment proved a success. The brain is an astonishing 60 percent fat, and it needs omega-3s to function properly. Salmon? As psychiatric regimens go, it may sound fishy.
But in a new book called "The Omega-3 Connection," Stoll argues that fish oils-with their high content of polyunsaturated, omega-3 fatty acids-may help a range of psychiatric disorders. The brain is an astonishing 60 percent fat, and it needs omega-3s to function properly. In the last century, however, Americans have drastically reduced their intake of these oils, as we moved to diets based on processed foods. This deficit, scientists agree, has contributed to an epidemic of heart disease.
Now a spate of cross-national studies has also linked low fish consumption to high rates of major depression, bipolar disorder, postpartum depression and suicidal tendencies.
"Heart disease and depression often go hand in hand," says Dr. Joseph Hibbeln, the National Institutes of Health psychiatrist who conducted a number of these surveys. "Now we may know why."
It is impossible to reduce the cause to a single explanation-especially since omega-3s may function differently in each of these conditions. For major depression, omega-3s appear to work in part by making it easier for the receptors on brain cells to process mood-related signals from neighboring neurons.
"Think of the receptor as a doorbell on a house," says Dr. Lauren Marengell of Baylor College of Medicine. Omega-3s provide the lubrication that frees up a stuck doorbell and allows it to respond to a messenger's touch. The same fats may combat bipolar disorder (which involves mania as well as depression) by inhibiting a process called signal transduction, which occurs inside a brain cell after a messenger has "rung the bell." In a normal brain, the process is orderly.
But in a bipolar patient, it's as if everyone in a house started running in different directions at the sound of the buzzer-and not necessarily answering the door. Omega-3s-like all the major medications used to treat bipolar disorder-help quiet this confusion. If a woman is low on omega-3s to begin with, this depletion may set the stage for postpartum depression. While omega-3s are important for everyone, an adequate supply is especially critical for infants and mothers.
Gestating and newborn babies often deplete their moms of these fats in order to nourish their own brains. If a woman is low on omega-3s to begin with, this depletion may set the stage for postpartum depression. A child takes in large amounts of these fats during the third trimester of gestation, and breast milk maintains a steady supply following birth. Infant formulas, by contrast, deliver very little. (The World Health Organization recommends supplementing formulas with omega-3s, but the U.S. Food and Drug Administration has not yet approved supplementation. The matter is under review.)
No one doubts that omega-3 fatty acids help build and maintain brain tissue. But can the same fats help treat psychiatric disorders?
Researchers have not conducted the large clinical trials needed to answer that question, but the early evidence is encouraging. When Stoll supplemented the medications of 30 bipolar patients with either 10 grams of omega-3s or a placebo, those getting the fish oil did so much better that he switched the controls over to fish oil just four months into a nine-month trial.
British doctors have also gotten impressive results in trials for depression and schizophrenia. Other researchers, however, have found negative or neutral results in pilot studies, so it's not yet possible to deem fish oil an effective therapy.
"The field is still in its infancy," cautions Hibbeln. "What we have now are provocative hypotheses, not a lot of hard-nosed data."
Fortunately, because omega-3s are a normal part of the diet, they have caused virtually no side effects in the trials. "Omega-3s just give back to the body what it requires for proper functioning," says Stoll.
So how can we boost our omega-3 levels? The American Heart Association has recently changed its dietary guidelines to recommend that adults eat at least two servings of fish each week. Oily fish such as anchovies, mackerel and salmon have the most omega-3s. (The FDA, however, recently warned pregnant women against eating four types of fish with high mercury levels-shark, swordfish, tilefish and king mackerel.) Flaxseed, flaxseed oil, wheat germ and walnuts are good sources, too, as are dark greens such as spinach and kale. You can also boost your omega-3 levels by switching from corn and soybean oil to canola oil.
Some hens are even fed flax and fishmeal to boost the levels of omega-3s in their egg yolks. Look for cartons that mention omega-3 levels. Beyond that, says Stoll, your best bet is supplements. For general health, one to two grams of omega-3s a day should be sufficient. To correct mood problems, two to five grams or more may be required.
For all their promise, omega-3 fatty acids won't replace Prozac. Except in mild cases, omega-3s will likely be an adjunct to standard therapy. Stoll calls them "an 'and' rather than an 'or'." "Many factors play a role in modifying depression," says Hibbeln. "People are too complex to be governed by one or two molecules." But look on the bright side. Even if omega-3s don't leave you depression-proof, they'll boost your heart health. It's hard to be downbeat about that.
© 2001 Newsweek, Inc.
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