With heart disease continuing to rank as the number one cause of death in the U.S., researchers at the Cardiac Rehabilitation and Prevention department at the Ochsner Heart and Vascular Institute in New Orleans have issued evidence that they say confirms the need for omega 3 purified fatty acids to join the ranks of other vitamins and minerals that bear recommended daily intake (RDI) values.

The study, published in the Journal of the American College of Cardiology (Aug. 11, 2009), reviewed data from a broad range of studies spanning about 40,000 patients ranging from healthy individuals to those who had experienced a heart attack or other cardiac problem, and concluded that supplementation would not only help prevent cardiovascular diseases in healthy individuals, but also reduce the incidence of cardiac events and mortality in patients with existing heart disease.

“This isn’t just hype; we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years, that demonstrates the protective benefits of omega 3 fish oil in multiple aspects of preventive cardiology,” said Carl Lavie, MD, FACC, medical director of Cardiac Rehabilitation and Prevention, Ochsner Medical Center, and lead author of the article. “The strongest evidence of a cardioprotective effect of omega 3s appears in patients with established cardiovascular disease and following a heart attack with up to a 30% reduction in CV-related death.”

The study also underscored that the dietary intake of fish oil plays a vital role in the reduction of the risks of atherosclerosis, arrhythmias, heart attack, sudden cardiac death and even health failure. Dr. Lavie added that although there is a smaller benefit in reducing heart failure death—9% mortality benefit in a major recent randomized controlled trial—this is still impressive given patients’ grave prognosis.

“If we translate this finding, it means that we only need to treat 56 patients for four years to prevent one death,” he said. “And we are talking about a very safe and relatively inexpensive therapy.”

Most of the evidence for the cardioprotective benefits cited by the researchers supports the use of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). According to Dr. Lavie, EPA and DHA work by penetrating the membranes of cells and, in doing so, may help to improve the heart’s electrical activity, vascular tone, plaque stabilization and blood pressure, among other benefits. Studies show that the reduction in cardiovascular events is inversely related to the tissue level of EPA and, even more so, DHA.

Based on those findings, and because the body does not produce its own essential fatty acids, the authors recommended that healthy individuals should consume 500 mg daily of omega 3 fish oil containing EPA and DHA, and people with known heart disease or heart failure aim for at least 800 to 1000 mg daily.

“There are clear health and heart benefits associated with increasing one’s intake of foods that are rich in omega 3s, including oily fish like salmon, sardines, trout, herring, and oysters,” said Dr. Lavie. “Patients should talk with their doctors about whether a fish oil supplement is needed to get the right amount and, in turn, benefit from the associated cardiovascular protection.

Dr. Lavie and his team came across only a few negative studies, including a recent report that showed no benefit in post-MI patients, but it has raised the possibility that omega 3 fatty acids may not provide as much additional protective benefits in low-risk patients already receiving extensive and rigorous post-MI therapies. “It was a one-year study that enrolled fewer than 4000 patients and the majority were using aspirin, clopidogrel, statins, beta-blockers and ACE-inhibitors—the best of modern medicine,” he said. “It may be that their risk was so low to start, that a larger study with longer follow-up would be required to better assess the true efficacy of omega 3 in such relatively low-risk patients.”

The authors said further studies are needed to flesh out optimal dosages, as well as the relative ratio of DHA and EPA that provides maximal heart protection in those at risk of cardiovascular disease, and in the treatment of atherosclerosis, arrhythmias and heart attacks.

The reaction to the research team’s suggested omega 3 RDIs have been met primarily with support, although Dr. Robert Bonow, past president of the American Heart Association and co-director of the Bluhm Cardiovascular Institute at Northwestern University in Chicago, told ABC News that while advising patients to increase consumption of fish oil may be “good advice,” it should be tempered by adding the caveat that the data are “strongest in those with established heart disease…with the principal benefit being a reduction in serious rhythm problems.

“The other benefits do appear to be real, but there is less evidence—and in some cases no evidence—that these lead to better patient outcomes,” Dr. Bonow added.

Despite the dissention, it’s worth noting that The American Heart Association (AHA) already recommends those with confirmed coronary heart disease should consume 1000 mg of combined DHA + EPA every day. For healthy adults, the AHA recommends consuming 500 mg per day, which works out to about two servings of fatty fish a week.

Industry advocates for omega 3 are also on board. “In general, I thought (the study) provided an accurate representation (including limitations when applicable) of the current body of science for secondary prevention,” commented Harry Rice, director of Regulatory and Scientific Affairs, Global Organization for EPA and DHA (GOED). “The recommendation for primary prevention of 500 mg/day EPA + DHA is in line with GOED’s current position and other international recommendations. This review combined with the review by Harris et al., 2008 (Current Atherosclerosis Reports 10:503-509), which cited even more supporting studies, forms a clear and robust argument that anyone concerned about primary cardiovascular disease prevention should be consuming 500 mg/day EPA + DHA. We are very happy to see it called out since, historically, it has not received adequate attention.”