The fatty acid is called eicosapentaenoic acid (EPA). It's one of the disease-fighting omega-3 fatty acids.
In a study of more than 18,000 men and women, those who took high doses of EPA plus a cholesterol-lowering statin drug (either Zocor or Pravachol) were 19% less likely to suffer a variety of heart ailments, compared with those who took statins alone.
After 4.5 years, 2.8% of people taking the statin-EPA cocktail had adverse events vs. 3.5% in the statin-only group. The adverse events included sudden cardiac death, heart attacks, unstable angina, and the need to undergo procedures to reopen clogged arteries.
Further analysis showed that people with existing heart disease benefited most from the combination approach.
"Omega-3 fatty acids have powerful benefits in preventing adverse outcomes compared with statins alone," says researcher Mitsuhiro Yokoyama, MD, chief of cardiovascular and respiratory medicine at Kobe University Graduate School of Medicine.
The study was presented at the annual meeting for the American Heart Association.
Beyond Cholesterol-Lowering Benefits
Yokoyama tells WebMD that the omega-3 fatty acids seem to have a variety of heart-healthy benefits, including anticlotting effects and triglyceride-lowering effects, that go beyond cholesterol lowering.
"Both combination and statin-only therapy reduced LDL "bad" cholesterol by the same amount -- 26% -- yet double therapy lowered cardiovascular risk significantly more than single therapy," he says.
Lawrence Appel, MD, professor of medicine at Johns Hopkins University in Baltimore and an American Heart Association spokesman, says, "The study reinforces the benefits of fish oil in a high-risk population with prior cardiovascular disease." Appel was not involved in the study.
But he worries that the high dose of omega-3 fatty acids -- 1,800 milligrams of highly purified EPA in capsule form per day -- could be toxic. "That's roughly 10 times the dose you get in a typical capsule. Ten tablets a day could cause a lot of side effects."
The big unresolved issue, Appel tells WebMD, is whether omega-3 fatty acids will prevent heart attacks and stroke in healthy people that do not eat a lot of fish. The Japanese diet is about 40% fish, while the majority of Americans don't even eat fish three times a week.
"What we really need to do now in the U.S. is a big trial testing fatty acids in healthy people," he says.