EPA for Psych. & Neurodegen. Disease

A new review found controversial results from studies on the effects of eicosapentaenoic acid, a type of omega-3 fatty acid, on psychiatric and neurodegenerative diseases.

Neurodegenerative diseases are neurological disorders marked by the loss of nerve cells. Examples include Alzheimer's disease, Huntington's disease and Parkinson's disease.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are both contained in fish oil, as well as some nuts (English walnuts) and vegetable oils (canola, soybean, flaxseed/linseed and olive).

There is evidence from multiple large-scale population (epidemiologic) studies and randomized controlled trials that intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements lowers triglycerides, reduces the risk of death, heart attack, dangerous abnormal heart rhythms and stroke in people with known cardiovascular disease, slows the buildup of atherosclerotic plaques ("hardening of the arteries") and lowers blood pressure slightly. However, high doses may have harmful effects, such as an increased risk of bleeding.

Researchers from the University of Prince Edward Island in Canada explained that decreased n-3 fatty acid levels have been reported in patients with depression, schizophrenia or Alzheimer's disease.

The review reported that recently, EPA has been used to treat several psychiatric and neurodegenerative diseases due to its anti-inflammatory and neuroprotective effects. A total of six out of seven clinical trials have shown that EPA significantly improved symptoms of depression when compared with the placebo-treated populations.

Several investigations have also reported that EPA could effectively treat schizophrenia. A case report and a clinical trial have shown that EPA was beneficial for the management of most symptoms of Huntington's disease, while a more extensive clinical investigation has demonstrated that EPA could only improve motor functions.

The authors concluded that further clinical studies are required to fully explore the effects of EPA on other neurodegenerative diseases. The limitations of previous studies and further research directions were also discussed in the review.

The American Heart Association (AHA) recommends including fish in the diet for all individuals, and fish oil supplements in those with a history of cardiovascular disease.

Fish oil has been suggested as beneficial in conditions associated with low levels of omega-3 fatty acids (in plasma and/or membrane phospholipids) such as some psychiatric disorders. For mood disorders, Dr. Andrew Stoll of HarvardUniversity has recommended 3-10 grams daily of EPA and DHA, in three divided doses with meals. Dr. Dean Ornish (creator of the Ornish diet ®) has recommended 2 grams per day of fish oil (MaxEPA®) for "cardiovascular improvement."

For more information on EPA and other omega-3 fatty acids, please visit Natural Standard's Herbs & Supplements database.

To comment on this story, please click here to enter the Natural Standard blog.

References:

1) Song C, Zhao S. Omega-3 fatty acid eicosapentaenoic acid. A new treatment for psychiatric and neurodegenerative diseases: a review of clinical investigations. Expert Opin Investig Drugs. 2007 Oct;16(10):1627-38. View Abstract.

2) Natural Standard Research Collaboration: The Authority on Integrative Medicine. www.naturalstandard.com. Copyright © 2007.