NEW YORK - Fish oil could
potentially save more lives than cardiac defibrillators, devices used to revive
individuals whose hearts have stopped beating and to prevent and treat
life-threatening heart arrhythmias, researchers estimate in a new report.
Past research has linked the omega-3 fatty acids found in oily fish to a
lower risk of fatal heart rhythm disturbances. This latest study tried to
estimate the potential public health impact of raising adults' omega-3 levels
with fish oil supplements.
Using a computer-simulated community of 100,000 Americans and data from past
medical studies, the researchers calculated that raising omega-3 levels would
save 58 lives each year.
This amounts to a 6.4-percent total death reduction -- mostly by preventing
sudden cardiac death in apparently people, according to the study authors, led
by Dr. Thomas E. Kottke of the Heart Center at Regions Hospital in St. Paul,
Minnesota.
Conversely, the researchers estimate that far fewer lives would be saved by
defibrillators, devices that deliver a "shock" to restart the heart or to
resolve ventricular fibrillation, an otherwise fatal heartbeat irregularity in
which the heart quivers instead of contracting normally.
For example, the study found, even if automated external defibrillators
(AEDs) were available in every home and public area, the devices would lower a
community's annual death rate by less than 1 percent.
AEDs are portable devices that can be used by lay people to shock someone in
cardiac arrest. They are frequently available in public places such as large
stores or on airplanes. Though the devices do save lives, the researchers note
that AEDs would make little difference in the overall rate of sudden cardiac
death.
Kottke's team estimates that implantable defibrillators would lower the
cardiac death rate by 3.3 percent, still not as much as the 6.6-percent lower
death rate achieved by increasing the use of fish oil supplements.
Though the implantable devices are effective, the researchers point out that
about half of adults who die suddenly from cardiac arrest have no warning signs
beforehand -- and would, therefore, never be candidates for an implanted
defibrillator.
The study, which is published in the American Journal of Preventive Medicine,
has its limitations, as a computer simulation. Though the researchers based
their estimates of fish oil benefits on two large studies, it's not yet clear
that omega-3 fatty acids prevent sudden cardiac death in apparently healthy
people.
Ongoing trials in Italy and England may help answer this question, Kottke and
his colleagues note.
If fish oil is as effective against fatal heart arrhythmias as evidence
suggests, the researchers conclude, it would have more widespread benefits than
either AEDs or implanted defibrillators.
SOURCE: American Journal of Preventive Medicine, October
2006.
