Omega-3 levels in orbitofrontal cortex linked to schizophrenia

[David Baxter PhD]

Omega-3 levels in orbitofrontal cortex linked to schizophrenia
03 April 2007
Schizophr Res 2007; 91: 37?50

Deficiency of omega-3 fatty acid in the orbitofrontal cortex (OBC) appears to play a role in the pathophysiology of schizophrenia, say US researchers.

The findings suggest that such deficiencies are gender-specific and partially normalized by antipsychotic medications, they add.

Patients with drug-na?ve, first-episode schizophrenia have been shown in previous studies to have significant abnormalities in the fatty acid composition of peripheral tissues, particularly in omega-3 and omega-6 polyunsaturated fatty acids. These abnormalities are partially normalized by chronic antipsychotic treatment.

Robert McNamara, from University of Cincinnati College of Medicine in Ohio, and colleagues determined the total fatty acid composition of OFCs obtained at postmortem from 21 drug-free and antipsychotic-treated schizophrenia patients and 26 age-matched controls.

Using gas chromatography and correcting for multiple comparisons, the team found that the OFC of schizophrenia patients had 20% lower docosahexaenoic acid (DHA) concentrations and 12.5% greater levels of vacceinic acid (VA) than controls, the team notes in the journal Schizophrenia Research.

Further analysis showed that male patients had deficits in DHA in the OFC, along with increased ratios of arachidonic acid (AA) to DHA and oleic acid (OA) to DHA compared with male controls. However, no such differences were found in female patients.

Schizophrenia patients who had died of cardiovascular diseases had 31% lower DHA and 19% lower AA concentrations, along with 20% greater OA and 17% higher VA levels, than their peers without schizophrenia.

Furthermore, the DHA and AA deficits, and increases in OA and VA, in the OFC were numerically greater in drug-free schizophrenia patients than in those treated with antipsychotic medications. The alterations in patients treated with antipsychotic medication were partially normalized.

It was also found that the abnormalities could be attributed wholly to lifestyle factors or postmortem tissue variables.

The team writes: "The present data therefore have implications for future clinical trials because they would suggest, for example, that drug-free male schizophrenia patients would exhibit the greatest benefit from omega-3 fatty acid treatment, whereas atypical antipsychotic-treated female schizophrenia patients would exhibit the least benefit."

Free abstract

 

[HA]

Here is an interesting article on Omega-3's from 1995 (links have updated information):

Most Canadians not getting enough omega 3s
CTV News Toronto

Recent studies suggest limiting the intake of some fish because of contaminants. But fish are a rich source of omega 3 fatty acids and many more studies suggest we are simply not getting enough.

Health groups have urged consumers to limit their intake of farmed salmon which can have high levels of PCBs, and limiting tuna and other fish because of mercury.

With the studies raising concerns about the man-made pollutants in our seas, some fish shop owners have watched sales slide by as much as 50 per cent.

And that worries some doctors who say their patients are not getting enough omega 3s -- essential fatty acids that some plants provide in small amounts, but are in rich supplies in fish.

Studies suggest those who don't get enough omega 3 fatty acids appear prone to a number of diseases.

"That includes certain forms of cancer, diabetes, arthritis, and other autoimmune disorders like lupus," says Dr. Peter Jones of McGill University.

Omega 3s are vital for brain and eye development in children. They are anti-inflammatories in adults and studies suggest they prevent heart disease and macular degeneration. Deficiencies of omega 3s are also linked to depression and schizophrenia.

The American Heart Association says omega 3s can help decrease irregular heartbeat, decrease triglyceride levels, and decrease growth rate of plaque in the arteries.

Yet more than 50 per cent of Canadians are already deficient in omega 3s -- even though many say they eat fish.

"Unfortunately, much of the fish that North Americans are eating is breaded fish," says Professor Bruce Holub of the University of Guelph.

"And so they're getting high trans fats and low omega 3s -- 10 parts of trans for every one part omega 3s."

Now, a Canadian company, NutraSource Diagnostics, is commercializing a simple blood test that allows doctors to measure how much of the fish oils a patient may need.

And for the first time, it's being rolled-out through the health care system.

"This test measures the levels of EPA and DHA in your blood. Based on results, you are advised to maintain or increase your intake of these vital nutrients," NutraSource president Will Rowe told CTV.

Dr. Tom Barnard has been using the newly developed test with many of his patients.

"I've tested hundreds of people and most have virtually no omega 3s," he says.

One of Barnard's patients is Andre Maloche, a nine-year-old with colitis, a painful digestive disorder. When tests showed he was seriously deficient in omega 3s, Dr. Barnard suggested high doses of fish oil in the form of capsules.

"I just feel better, more energetic, more strong. And I just had a good feeling when I started taking it," he says.

His improvement may be due to chance, but his parents are convinced the fish oils played a role.

"We noticed that when he gets sick we don't hear much about it. He still has the occasional headache, but nothing even close to what it was before," says his mother Adrianna Maloche.

Some researchers believe the omega 3 blood test will become commonplace in the next five years as doctors learn much more about how our bodies need these omega 3 oils.

In the meantime, the director of McGill's School of Dietetics and Human Nutrition says the test should prove useful for a growing cross-section of the population.

"Testing omega-3 levels in blood is important," Dr. Peter Jones said, "because recent data from leading scientists in the area have shown a closer association between heart disease risk and omega 3 fats than has been shown for our leading indicator of heart disease health which is bad cholesterol."

"That's really astounding."


American Heart Association: Fish, Mercury, and Omega-3 Fatty Acids

Heart & Stroke Foundation - The reel deal on salmon

Health Canada - Food safety and PCBs found in fish

MDS Diagnostic Services - Omega 3 blood test (.pdf file)

NutraSource Diagnostics - Omega 3 Profiles Test

CMAJ - Omega 3 fatty acids in cardiovascular care

American Journal of Clinical Nutrition - Effects of supplementation with fish oil-derived n-3 fatty acids and gamma-linolenic acid on on circulating plasma lipids and fatty acid profiles in women

Dr. Bruce Holub - nutritional sciences, Guelph University