Omega-3 Fatty Acid May Protect Heart
EPA, a Fatty Acid in Fish Oil, May Prevent Nonfatal Heart Problems
March 29, 2007 -- An omega-3 fatty acid found in fish oil may help prevent
nonfatal heart problems in some people with high cholesterol, a Japanese study
The omega-3 fatty acid is called EPA (eicosapentaenoic acid). It's found in
fish such as salmon and mackerel, along with another fatty acid called DHA
The Japanese study looked at more than 18,600 adults with high cholesterol,
including 3,660 people with a history of coronary artery disease.
The coronary arteries supply blood to heart muscle. Unhealthy coronary
arteries make heart attacks more likely, and high cholesterol is a risk factor
for coronary artery disease.
Study participants were followed for more than four years, on average.
During that time, they all took cholesterol-lowering statin drugs.
The researchers assigned half the participants to also take pills containing
highly purified EPA. For comparison, the other participants only took their
statins, with no EPA pills.
Then the researchers tracked major coronary events, such as sudden cardiac
death, fatal or nonfatal heart attack, or other nonfatal heart problems, in
both groups for 4.6 years, on average.
During the study, the vast majority of patients had no major heart
However, 2.8% of those taking EPA along with statins experienced a major
coronary event, compared with 3.5% of those only taking statins.
That's a 19% difference, note the researchers, who included Mitsuhiro
Yokoyama, MD, of Kobe University in Kobe, Japan.
EPA pills weren't linked to any difference in fatal heart attacks or sudden
When Yokoyama's team took a closer look at the data, they found the EPA
advantage only applied to patients with a known history of coronary artery
Patients with high cholesterol but no history of coronary artery disease may
also get some heart protection from EPA, but that's not certain, since so few
of them had major heart problems during the study.
The researchers conclude that EPA is a "promising treatment" for the
prevention of heart problems in Japanese patients with high cholesterol.
Fish is a staple of the traditional Japanese diet. That may partly explain
why EPA pills didn't seem to curb fatal heart events. "Our patients could
possibly all have had intakes of fish that were above the threshold for
prevention of fatal coronary events or sudden cardiac death," write
Yokoyama and colleagues.
The researchers didn't ask patients about their diets.
Yokoyama's team also warns that the findings might not apply to people who
don't eat lots of fish. "EPA might affect risk only at very high levels of
fish intake, such as those common in Japan," they write.
Lastly, the researchers note that they only tested EPA pills, not fish or
fish oil. The pills were made in Japan by Mochida Pharmaceutical Co., which
funded the study.