January 16, 2019 by Laura Pincus and Patty Shillington
Prescribed, Pure Omega-3 Fish Oil Lowers Heart Attack, Stroke Risk For Some, Study Finds
A new, large clinical trial may be the first step in preventing heart attacks and strokes in some high-risk patients thanks to large doses of a certain omega-3 fatty acid found in fish oil.
The findings from this trial can be of primary benefit to people with persistently elevated levels of triglycerides, a type of fat (lipid) found in a persons’ blood. These patients have cardiovascular disease or diabetes, and other risk factors — but have controlled cholesterol levels via statin therapy.
Researchers concluded that adults treated with statins to control cholesterol levels — but still had high levels of triglycerides — had a 25 percent reduction in their relative risk of heart attacks, strokes and other cardiac events after being prescribed high doses of the purified EPA, an omega-3 fatty acid. Their results were compared to a control group of patients who received a placebo, or pill with no medical or therapeutic effect. Both groups had good cholesterol control with statins.
The trial’s findings, which involve the drug Vascepa, came as a surprise to many cardiovascular experts who had previously placed confidence on smaller, less significant studies that found little or no benefits to adding fish oil to statin therapy for lowering heart attack and stroke risks.
Moreover, many studies have found that popular “fish oils containing omega-3” fatty acid products, which include supplements promoted extensively as helping lower cholesterol levels, are ineffective for the prevention of heart disease. This new research involving large doses of prescription EPA has no relation to these popular supplements, emphasizes Jonathan Fialkow, M.D., Deputy Medical Director Chief of Cardiology and a certified lipid specialist at Miami Cardiac & Vascular Institute at Baptist Hospital.
EPA and DHA are the primary omega-3 fatty acids believed to have cardiovascular benefits. Dietary supplements have varying levels of DHA and EPA, and often, high levels of other fats including saturated fats. Prescription omega-3 medications are pure omega-3. Some have combinations of EPA and DHA. In the case of this most recent study, Vascepa is a prescription drug that contains highly purified EPA.
The study, which enrolled 8,179 adults and followed them on average for about five years, is the first of its kind and marks an important milestone in the use of prescribed omega-3s, says Dr. Fialkow. The trial found that Vascepa was safe.
Amarin, the manufacturer of the drug, is expected to present the full results and data at an annual American Heart Association conference in November. The next step is for the trial’s data to be fully reviewed by the medical community and then reviewed by the U.S. Food and Drug Administration (FDA). While the FDA has already approved Vascepa for lowering triglyceride levels, the agency would have to approve the pure EPA drug for use in the specific classification of high-risk patients like those treated in the trial.
“There’s never been a pure omega-3 outcome trial,” says Dr. Fialkow. “There have been lots of small trials looking at the benefits of fish oil. This trial uses a much higher omega-3 dosing in a pure form. So there has been some confusion. But this one is looking at the benefits of prescription-grade omega-3.”
The Vascepa trial focused on two groups of high-risk patients: People with a history of cardiovascular events, such as heart attacks, strokes and angina; and people with type 2 diabetes and other risk factors such as high blood pressure or tobacco use. The patients also had to have high triglycerides. The median baseline level of triglycerides among the subjects was 216 milligrams per deciliter — well above what is considered normal, which is 150 milligrams per deciliter. In addition, all of the patients were on statins, which lower cholesterol.
“In this high-risk population, the elevated triglycerides is a marker of something going on in their bodies that produces continued cardiovascular risk and now we have an additional weapon that will lower their risk — on top of statin therapy,” explains Dr. Fialkow.
However, Dr. Fialkow is concerned that the general public might be more confused about omega-3s and that marketers of fish oil supplements might use these new findings as a sales booster.
Earlier this year, a large review of randomized trials found no association between regular consumption of the fish oil supplements that contained omega-3 and a lowered risk for death from heart disease, or nonfatal heart attacks or other major cardiovascular events. The analysis, published in JAMA Cardiology, pooled data from 10 randomized trials focusing on people who had had cardiovascular disease or were at high risk for heart disease.
Omega-3 fatty acids are essential parts of heart healthy diet. However, fish oils in omega-3 dietary supplements contain lower levels of EPA and DHA than prescription products and are not approved or intended to treat disease.
“This trial represents a promising new weapon in a high-risk population, but I can foresee companies that manufacture cheap, poorly defined fish oil products with no benefits try to profit from the results of this study.” says Dr. Fialkow. “This study is about a whole different substance, a prescription-strength pure omega-3.”