4/16/01 Nourishing Your Brain
NEWSWEEK April 23 issue
By Anne Underwood
Its 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
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 Stolls office at Brigham and Womens Hospital. Stoll
tried all the usual medications. But lithium alone didnt work, and Patient X
was unable to tolerate the side effects of strong antipsychotic drugs. Thats
when Stoll, an assistant professor of psychiatry at Harvard, turned to a more
unconventional remedyhe instructed Patient X to eat a quarter pound of
salmon every day, while continuing to take his lithium. The treatment proved
Salmon? As psychiatric regimens go, it may sound fishy. But in a new
book called The Omega-3 Connection, Stoll argues that fish oilswith their
high content of polyunsaturated, omega-3 fatty acidsmay 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
explanationespecially 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 messengers 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, its as if everyone in a house started running in different
directions at the sound of the buzzerand not necessarily answering the door.
Omega-3slike all the major medications used to treat bipolar disorderhelp
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 its 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.