Research Update on Fish Oil Supplements
Researchers performed a meta-analysis of studies that examined EPA and DHA as dietary supplements to see if there was a reduction in CVD events and mortality. In this study, researchers included 40 studies with 135,267 participants. While they examined many different variables, including whether EPA was better than DHA and whether they could find the best combination or ratio, almost every analysis they ran demonstrated benefits for those who use fish oil supplements: a 13% decrease in the risk of a heart attack, a 10% decrease in any coronary heart disease event, and a 35% reduction in the risk of a fatal heart attack.
For me, the most significant finding was that there was a dose-response effect of taking fish oil supplements. In other words, CVD events decreased with higher intake of fish oil supplements.
The Problems with the Prescription Study
There were three issues with the EVAPORATE study I talked about in Thursday’s Memo. First, there was a significant loss of subjects. Most of the loss was in the experimental group, which reduced the number of subjects from 40 to 31.
Second, they did not compare the prescription fish oil with an equivalent amount of fish oil dietary supplement, whether it contained DHA or not, which seems to be a glaring omission to me.
Finally, the study was funded by the manufacturer; several of the researchers had a relationship with the pharmaceutical manufacturer as well. That doesn’t mean anything shady was going on, but it does put in question the conclusions that can be drawn about the significance of the entire clinical trial.
The Problem with the Fish Oil Supplement Study
The primary problem with the fish oil supplement study is that it was a meta-analysis. Even though that method is becoming popular, and even though by all accounts the researchers tried their best in selecting the correct studies for inclusion, there’s always the specter that they may have left out some studies. To their credit, they re-ran the analysis without several of the clinical trials and did get slightly different findings. However, it did not change the outcomes related to heart attacks or coronary heart disease events.
The study was funded by Global Organization for EPA and DHA Omega-3s. Just as with the pharmaceutical study, there’s an inherent bias implied. In both cases though, if the funding organizations didn’t sponsor the research, who would? There are only so many research dollars available, and many dollars are being siphoned off to fund urgent COVID-19 studies.
The Bottom Line
I think that these studies establish that fish oil is beneficial to reduce CVD events and reduce disease progression. Because there appears to be a dose-response relationship to fish oil and the reduction of CVD risk, the higher amount of fish oil a person takes, up to four grams, the better the potential outcomes.
Which one is better: prescription versus supplements? Until there’s a study that directly compares prescription fish oil to fish oil supplements, I don’t believe it matters; both studies we reviewed demonstrate benefits. The key is that if you have been diagnosed with CVD, you should take fish oil. Talk it over with your physician first and then get going. Your heart will love you for it. And don’t forget to eat better and move more as well.
What are you prepared to do today?
Dr. Chet
References:
1. European Heart Journal (2020) 00, 1–8 doi:10.1093/eurheartj/ehaa652
2. https://doi.org/10.1016/j.mayocp.2020.08.034
