Omega 3: The Good, the Bad, and the Ineffective

Fish oil shown to reduce risk of heart failure and psychotic disorders, but ineffective against atrial fibrillation

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Omega-3 fatty acid (fish oil) supplements have been shown to boost heart health and even fight against psychotic episodes in certain studies, but a new report claims the supplement is ineffective against atrial fibrillation (AF).

AF is a highly prevalent disorder of the heart that results in irregular heartbeats, putting sufferers at risk of heart attack and stroke. Previous studies had indicated omega-3 polyunsaturated fatty acids might offer a safe, effective treatment option for AF, but new research from the Lankenau Institute for Medical Research, Wynnewood, Pa., suggests the treatment lacks efficacy.

In a randomized clinical trial, researchers looked at prescription omega-3 fatty acids in 663 AF patients at a significantly higher dose than what had been tested in previous trials. Most of the patients (542) had symptomatic paroxysmal (sudden attacks) of AF while 121 exhibited persistent AF.

After a six-month follow-up, the scientists found a total of 147 AF events (46 percent) in the placebo group and 167 (52 percent) in the prescription group.

Fish oil has also proven ineffective in the fight against Alzheimer's disease (AD), contradicting prior studies that suggested the supplement's possible benefit for AD patients. In a study from the Oregon Health and Science University and the Portland VA Medical Center in Portland, Ore., patients did not experience a reduction in the rate of cognitive and functional decline compared to patients who received placebo.

Omega-3 fatty acids have shown efficacy in reducing psychosis in individuals at extremely high risk of developing mental illness. These patients appeared less likely to develop psychotic disorders following 12 weeks taking fish oil supplements that contained long-chain omega-3 polyunsaturated fatty acids, according to researchers at the Medical University of Vienna and the Orygen Youth Health Research Centre in Melbourne, Australia, who conducted a randomized, double-blind, placebo-controlled clinical trial.

Eating fatty fish such as salmon also has been shown to reduce the risk of heart failure, building on previous research suggesting these fish and omega-3 fatty acids in general help fight risk factors for a score of heart-related conditions by lowering triglycerides (fats in the blood) and reducing blood pressure and heart rate.

Heart failure, the leading cause of hospitalization among patients 65 and older, is characterized by weakness, fatigue, persistent wheezing and rapid or irregular heartbeat. This life-threatening condition occurs when the heart cannot pump enough blood to meet the body's requirements.

Researchers at the Cardiovascular Epidemiology Research Center in Sweden found that men who ate fatty fish (herring, mackerel, salmon, whitefish and char) once a week were 12 percent less likely to develop heart failure compared with men who ate no fatty fish in a study. Researchers followed 39,367 Swedish men between the ages of 45 and 79 from 1998 to 2004.

Reviewed by: 
Review Date: 
December 28, 2010
Last Updated:
December 29, 2010