пятница, 14 сентября 2012 г.

Health Benefits of Fatty Acids - NPR Morning Edition

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BOB EDWARDS, HOST: There is some clear evidence that fish oil is good for your heart. In a recent study, men who ate fatty fish like tuna, salmon and mackerel once a week cut their chances of a heart attack by half. Researchers are becoming interested in how fish oil works in the brain. NPR's Rebecca Perl reports that some researchers think it may be effective in treating some mental illnesses.

REBECCA PERL, NPR REPORTER: It could be a coincidence, but some scientists think there may be a link between these two facts. First, the incidence of depression in the United States has been on a steady increase since the beginning of this century. Second, Omega 3 (ph) essential fatty acids, which play a critical role in the brain, have largely been eliminated from the American diet during this same period.

Dr. Joseph Hiblin (ph), a research psychiatrist at the National Institutes of Health, says that it's possible that dietary changes have resulted in there being too little of these fatty acids in the membrane of neurons or brain cells, and this, he says, may impair their ability to communicate with one another.

DR. JOSEPH HIBLIN, RESEARCH PSYCHIATRIST, NATIONAL INSTITUTES OF HEALTH: Human beings, the crowning achievement of their evolution has been the development of their mind. And so what I'm suggesting is that perhaps the first thing to go because of these nutritional changes are some of our more delicate and poetic aspects that we have evolved: the functions of the mind.

PERL: Omega 3 fatty acids come from fish and leafy green plants and canola oil, foods most people don't eat a whole lot of. Also, the amount of Omega 3s we do consume may not get into brain cells. That's because the modern American diet is awash with Omega 6 fatty acids, which compete with the Omega 3s. The ubiquitous Omega 6s come from corn and soybean oils which in contrast are found in nearly everything we eat. According to Hiblin, this altered fatty acid ratio could account for some mental imbalances.

HIBLIN: It's as if these fatty acids are the concrete that build the walls and structures of these neurons. Just as if you change the foundation of a house, more than one system is going to be affected.

If the house is a little bit out of kilter the windows are going to be a little bit off, the electrical system's going to be a little bit off, maybe the plumbling'll leak. Now what that translates to for a brain is that you have billions of different cells and connections all firing and communicating with each other, all that are just a little bit off kilter, and this may result in a variety of different manifestations of psychiatric disorders and psychiatric illnesses.

PERL: Recently, Hiblin gathered together scientists doing research on Omega 3 fatty acids to see what they're coming up with.

Researchers are looking at the role of fatty acids in mental disorders and in the developing brain of infants. In England researchers have found that giving certain components of fish oil to schizophrenics along with their normal medication reduced symptoms, including hallucinations, delusions and paranoia, by 25 percent.

A study done at Harvard by Dr. Andrew Stowell (ph) looked at manic depression. Stowell compared patients who took large doses of fish oil along with their regular medication to those who got a placebo.

DR. ANDREW STOWELL, ASSOCIATE PROFESSOR OF PSYCHIATRY, HARVARD MEDICAL SCHOOL: We found that the patients receiving the concentrated fish oil did far better clinically. They had fewer recurrences of mania, fewer recurrences of depression. And there were no side effects to the treatment either.

PERL: Stowell, who is an associate professor of psychiatry at Harvard Medical School, said the study was supposed to last nine months.

STOWELL: We took a preliminary look at the data at four months and the differences were so striking that we stopped the study at that point.

PERL: Stopped the study and put all the patients on fish oil supplements. Researchers say these results sound promising, but they've not been published yet, nor have they been replicated by another university, something that is key to confirming the original findings.

Interest in fish oil's role in treating mental disorders grew out of research on monkeys that suggests that fatty acids may play an important role in the development of their brains. Now some scientists are doing tests on human infants and say that fatty acids should be added to infant formula. Fatty acids are present in breast milk and are already added to formulas in Europe and Japan.

DR. MARTHA NEURINGER (PH), ASSOCIATE PROFESSOR, OREGON HEALTH SCIENCES UNIVERSITY: In the United States the FDA and the formula companies have been more cautious. And I don't think that that's necessarily a bad thing. Because we're talking about something that's going to be fed to millions of babies.

PERL: Dr. Martha Neuringer is an associate professor at Oregon Health Sciences University. She says fatty acids play an important role in the eye. They make up about a quarter of the part of the retina that initiates vision. So fatty acids have a critical effect on how quickly and how well an infant sees. Now scientists in this country are grappling with whether adding fatty acids will benefit newborn development.

NEURINGER: In general, in pre-term infants the results have shown improvements in visual acuity development with supplementation.

I think in full terms the evidence is tending in that direction. And when concerns about safety of the formulas are answers, I think they will be by, you know, undergoing clinical trials. Then I think it may be appropriate.

PERL: An even more conservative voice on the role of fatty acids is Dr. Richard Wyatt (ph), chief of the Neuropsychiatry Branch of the National Institutes of Mental Health in Bethesda.

DR. RICHARD WYATT, CHIEF, NEUROPSYCHIATRY BRANCH, NATIONAL INSTITUTES OF MENTAL HEALTH: My major skepticism about it is that there are too many claims. It's almost as if the substance could walk on water, and that hasn't happened for a few thousand few.

PERL: Wyatt says he's seen other substances that have been held up as painless panaceas, some vitamins, for instance, that turned out to be of minimal help. But he says if fish oil could help with even one mental disorder, that would be extremely fortunate. And he cautions that sometimes when you want something badly enough it has a way of slipping into the data.

WYATT: I think we're all a bit desperate for cures and treatments and we like things to be easy, and sometimes they are, most of the time they're not, they require a bit more work and effort than alternative medicine, other kinds of medicines (unintelligible). Now, occasionally they're going to provide something that's going to surprise us, and when it does that's wonderful, but it's not going to be often.

PERL: But Joseph Hiblin of the National Institutes of Health says that's exactly why scientists are building hypotheses, gathering at meetings, and doing studies: to put Omega 3 fatty acids to the hard test and see what they can do.

Rebecca Perl, NPR News, Washington.

This is a rush transcript. This copy may not be in its final form and may be updated.

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