A Cochrane review in July of 2018 found no real benefit to fish oil in reducing risks of heart attack, stroke or cardiovascular risk. That challenged the conventional belief that this was one over-the-counter supplement that actually worked. However, a few recent studies have contradicted the Cochrane review and found there may be some benefit after all. How does this new data affect you and your patients?
REDUCE-IT has the most promising data on fish oil and the reduction of cardiovascular risks so far. REDUCE-IT demonstrated a statistically significant relative risk reduction of 25% in the first occurrence of major adverse cardiovascular events in individuals provided 4 grams/day of Vascepa, a prescription fish oil, compared to those receiving placebo.
The patients in REDUCE-IT were patients with high triglycerides despite already being treated with statins. It’s also of interest that Vascepa is EPA only, where most fish oils are a mixture of EPA and DHA. With the over-the-counter variety, it’s always unclear exactly what the ratio is. Even if it is stated on the label, you never know what you’re getting. Another important point is that patients in REDUCE-IT got 4 grams of Vascepa every day. Most clinicians recommend 1 gram daily.
Other recent studies have shown some benefit in combination fish oils with lower doses. The recent ASCEND study studied the effects of 1000 mg of fish oil in patients with diabetes. August 2018, showed that there were fewer vascular deaths in the EPA/DHA group than in the placebo group. The reduction in total coronary death was not significant. These results were not as promising as the REDUCE-IT trial but did show some benefit to fish oil supplementation.
VITAL studied Omacor, a prescription combination of EPA and DHA, and vitamin D. The primary endpoint in this trial was the prevention of cardiovascular events and cancer in men 50 years of age or older and in women 55 years of age or older. The primary cardiovascular event endpoint included myocardial infarction, stroke, or death from CVD.
VITAL did not find Omacor was effective for primary prevention of CV or cancer events among healthy middle-aged men and women over 5 years of follow-up. VITAL did find significant differences in some of the secondary endpoints. Omacor reduced the risk of total MI by 28% and of coronary heart disease by 17%. This was the first large-scale primary prevention trial looking at heart disease as an outcome.
What does this mean to your patients? It appears that fish oil is probably beneficial, but I’m not sure it is beneficial enough to recommend to everyone. REDUCE-IT tested a very specific population: patients with elevated triglycerides who were already being treated with a statin. As seen by the Cochrane Review and VITAL and ASCEND, the data on more diverse populations isn’t as conclusive.
Most insurances don’t cover fish oil, though that will change if evidence dictates. Currently,
An interesting finding from VITAL was that African Americans and people with lower fish intake benefited more from fish oil than others. So, what I do recommend to my patients is that maybe they take an OTC fish oil supplement if it makes them feel better, but definitely eat those healthy fish that are high in EPA, like:
- Sturgeon fish
- Rainbow trout
As an added benefit to the potential cardiovascular risk reduction, replacing a red meat meal with fish leads to an overall healthy diet. It’s always better to get it from your diet than from a supplement when possible.