Fish Oil Prevents Deadly Irregular Heartbeats
Anti-Arrhythmic Effects May Help Explain Heart-Healthy Benefits of Fish Oil
April 30, 2004 -- A fish oil infusion may help prevent a
potentially deadly quickening of the heart (arrhythmia) in people at risk for
sudden cardiac death, a new study shows.
Although more studies will be needed to confirm these results,
researchers say these early findings may help explain how fish oil appears to
reduce the risk of sudden cardiac death in certain people.
Several studies have shown that a diet rich in fatty fish or
use of fish oil supplements containing omega-3 fatty acids can reduce the risk
of sudden cardiac death. But until now researchers have been unable to provide
direct evidence of how fish oils may work to prevent the irregular heartbeats,
known as arrhythmias, often responsible for triggering sudden cardiac
Fish Oil Protects Heart
In the study, published in this week's issue of The
Lancet, researchers examined the effects of fish oil in 10 people at high
risk for sudden cardiac death. The patients all had implanted defibrillators
(to shock their hearts out of a dangerous arrhythmia if needed) and a history
of ventricular tachycardia, or a dangerous quickening of the heartbeat.
In the study, researchers injected the patients with an
infusion of omega-3 fatty acids and then tried to induce an episode of
ventricular tachycardia. At the start of the study, researchers were able to
induce this irregular heartbeat in seven out of 10 of the participants.
After the fish oil infusion was delivered, researchers were
only able to induce the arrhythmia in two of the patients, and the second was
only after a more aggressive attempt. In the remaining five, the fish oil
appeared to prevent the irregularity.
Although researchers say this was a small study designed to
look at the safety of using fish oil infusions in protecting against
ventricular arrhythmias, the results show that fish oil may have
In a commentary that accompanies the study, Christine Albert,
MD, of Brigham and Women's Hospital in Boston, says these results are only
preliminary. But combined with previous research, they provide a possible
mechanism that explains the selective benefits of fish oil in reducing sudden
cardiac death found in other studies.
"If these and other trials confirm the anti-arrhythmic
properties of these [omega-3 acids], fish oil may become a less toxic and more
appetizing alternative to traditional anti-arrhythmic," writes Albert.