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Expert offers insight on recent omega-3 trials, ideal candidates
New data from three recent large-scale trials assessing omega-3 supplementation have demonstrated mixed findings for different groups of patients, suggesting a cardiovascular benefit for some high-risk individuals assigned a prescription-grade agent and likely no benefit for a primary prevention population.
The studies, presented at the American Heart Association scientific sessions in November and the European Society of Cardiology in August, showed that for most adults, long-term supplementation with fish oil is not associated with a CV benefit, though select subgroups might see CV risk reduction. However, for patients at high CV risk with a high triglyceride level that persists with statin therapy, a clear omega-3 benefit was observed, according to Christie M. Ballantyne, MD, FACC, FACP, FAHA, FNLA, professor of medicine, chief of the section of cardiovascular research and director of the Center for Cardiometabolic Disease Prevention at Baylor College of Medicine.
Endocrine Today spoke with Ballantyne about the findings from the recent omega-3 studies, the distinction between prescription-grade omega-3 agents and over-the-counter fish oil supplements, and the continued importance of maintaining a healthy diet.
There are now data from several large-scale trials evaluating at omega-3 supplementation. What does the latest research say about the value of fish oil?
Ballantyne: There has been some very interesting data presented recently — at AHA in particular, where two studies, VITAL and REDUCE-IT, were presented back-to-back.
VITAL used a prescription-quality omega-3 formulation that contains DHA docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) at 1 g per day. That study missed its primary endpoint, and the trial presented a few months before, the ASCEND study, also missed its primary endpoint. They were both disappointing. However, results from REDUCE-IT were very different. VITAL was a general population study. For REDUCE-IT, participants had to be high-risk individuals. Most had clinical CVD or diabetes, were taking a statin and still had a triglyceride level over 150 mg/dL. Then the dose there was 4 g per day of pure EPA — and that study showed a benefit. It is difficult to compare these results across studies. What you can probably conclude is a low-dose of a mixture of DHA and EPA didn’t do anything, although there were some encouraging secondary analyses in VITAL. It didn’t hurt, and it may turn out that there was some benefit. However, for a high-risk population with high triglycerides on top of statin therapy, there is a benefit when using a much higher dose of EPA over 5 years’ duration — a long course of treatment.
How important is the omega-3 dose or formulation ?
Ballantyne: In both VITAL and REDUCE-IT, a prescription agent was used — VITAL just used a lower dose. I think that is important to remember. When we are talking about supplements, there is a difference between a supplement and a prescription agent.
An over-the-counter drug is an FDA-approved agent, which still has to undergo FDA inspections. Compare that with a supplement, which has an entirely different set of requirements in regard to the quality process, production and what they can put on the label. Data from these studies suggest that the dose and the formulation — along with who gets the therapy — may all be important.
How important is fish consumption vs. supplementation?
Ballantyne: We do want to start with a healthy diet. Most people would not like to ever get diabetes or have coronary heart disease. The data show that a healthy diet that is low in saturated fat and carbohydrates can help prevent type 2 diabetes and obesity.
Cold-water fish are a good source of protein and omega-3 fatty acids. They have healthy oils in them and protein, and you are not getting any carbohydrates if eating this kind of fish. It is a very healthy protein source and preferable to other sources that might be otherwise. Processed meat, for example, is unhealthy as is eating a lot of fatty red meat, which has a lot of saturated fat. For processed meat, the adverse data are clear. Do we really need to go vegan? I don’t think so. But clearly, eating more fish and cutting out processed meats makes a lot of sense.
In light of the recent trials (VITAL, REDUCE-IT, ASCEND), who are ideal candidates for omega-3 supplementation?
Ballantyne: Right now, we have the data that suggest that the high-risk individual with CVD — and I would go broad and say that includes MI, revascularization, stroke and peripheral arterial disease — who is prescribed statin therapy and still has a triglyceride level over 150 mg/dL could derive a benefit from a prescription-quality omega-3 agent. My guess is it may be beneficial for people with diabetes as well. However, we are talking about 4 g of EPA per day. Omega-3 supplements usually have about 120 mg to 180 mg of EPA, and the rest is DHA. You have to take a lot of capsules to get that much EPA.
VITAL was somewhat encouraging. Participants at higher risk had more benefit, even though VITAL overall was a negative study. I tend to be on the more enthusiastic side.
It always depends on the patient profile. If the person is at high risk, go with what you know works. What we know works is a prescription, highly purified agent at a high dose. For a person in a lower-risk category, we don’t know that a supplement works. It certainly doesn’t seem to hurt, and there might be some benefit for certain subgroups, but we just don’t know for sure. – by Regina Schaffer
Disclosure: Ballantyne reports he has received honoraria from Amgen.