People who had higher blood levels of omega-3 fatty acids at the time of a heart attack were far less likely to die or to have repeat heart attacks within three years, compared to those who had lower levels (J Am Coll Cardiol, Nov, 2020;76(18):2089-2097). The sources of omega-3s in the 944 heart attack patients in this study included both fish and plants.

Omega-3 fatty acids can help to lower high triglycerides, which may help to prevent heart muscle damage before and during a heart attack (Circulation, Aug 2, 2016;134(5):378–391). Omega-3s also significantly lower inflammation, an overactive immunity that increases heart attack risk (Cardiovasc Res, 2009;82:240-249). People whose diet includes deep-water fish are at a reduced risk for suffering and dying from a heart attack (Circulation, 2018;138:e35-e47).

Possible Benefits from Prescription Fish Oil Pills
If you have high blood levels of triglycerides (>150mg/dL), a major risk factor for heart attacks and diabetes, you may benefit from taking high-dose prescription fish oil omega-3 pills. Vascepa was the first FDA-approved drug to reduce cardiovascular risk among patients with elevated triglyceride levels, as an add-on to statin therapy (FDA press release, December 13, 2019). In a study of 8,179 patients over age 45 with a history of heart disease or diabetes, those who received Vascepa were significantly less likely to have a cardiovascular event such as a stroke or heart attack. Vascepa’s active ingredient is eicosapentaenoic acid or EPA, an omega-3 fatty acid derived from fish oil. Other prescription fish oil products approved by the FDA include Lovaza, Epanova and Omtryg.

The prescription sources of omega-3s appear to be preferable to over-the-counter fish oil pills because they are more concentrated and contain only EPA, while over-the-counter products contain both EPA and DHA (docosahexaenoic acid), which may raise LDL cholesterol. The prescription pills may also be less likely to be rancid or contaminated (Cardiovasc J Afr, 2013;24:297-302). However, they are expensive and will only be covered by insurance if you have the high triglycerides that they are approved to treat. Check with your doctor.

Get Your Omega-3s from Foods
The possible benefits of over-the-counter fish oil pills are controversial (Clinical Nutrition, May 19, 2017) and I believe that you should be able to get enough omega-3s from eating oily fish (such as salmon or sardines) and a wide variety of plants. Some foods are marketed as particularly rich sources of omega-3s — flaxseeds, chia seeds, hemp seeds, soybeans, seaweed, algae, perilla oil and so forth — but you can get plenty of omega-3s in your regular diet if you eat lots of ordinary vegetables, nuts, beans and other seeds. Omega-3 fatty acids are classified into short chain fatty acids found in plants and long chain fatty acids found in fish. The health-promoting benefits of omega-3s come primarily from the long chain omega-3s, but some of the short chain omega-3s in plants can be converted to long chain omega-3s, so you can get the heart attack preventing benefits with a healthful plant-based diet (J Am Coll Cardiol, 2020;76(18):2098-2101).

Issues with Over-the Counter Fish Oil Pills
• A review of ten large randomized studies that followed 77,917 people, average age 64, for an average of 4.4 years, showed that taking fish oil pills did not prevent heart attacks, heart diseases, or major clotting events such as strokes (JAMA Cardiology, Jan 31, 2018). These studies were done with healthy people and on those with prior histories of heart attacks, diabetes, high blood cholesterol, or taking statin drugs.
• More than 21 studies have shown that fish oil pills do not prevent or treat any form of heart disease (Curr Cardiol Rep, Jun, 2017;19(6):47).
• From 2005 to 2012, 22 studies showed no benefit in preventing heart attacks or strokes in high-risk populations including people who were obese, did not exercise, ate meat daily, smoked, had a history of heart disease, had high cholesterol, had high blood pressure or had Type 2 diabetes (JAMA Intern Med, 2014;174(3):460-462).
• A review of 28 studies showed that fish oil pills did not help to prevent heart attacks (Clinical Nutrition, May 19, 2017).
• A clinical trial of 12,000 people found that fish oil pills did not reduce the rate of death from heart attacks and strokes (N Engl J Med, May 9, 2013; 368:1800-1808).

The debate over possible benefits from fish oil pills probably occurs because there is no way to monitor the quality of the pills taken by the people in these studies. Stale omega-3 oils in pills can be harmful and increase heart attack risk, which would cancel out any benefits that might be shown. If you decide to take fish oil pills, cut open the first capsule in the bottle and smell it. If it has a strong fish-oil odor, get rid of them. See Check Those Fish Oil Pills

My Recommendations
• The evidence that eating fish twice a week helps to prevent heart attacks is so strong that I believe everyone should do that.
• If you don’t like fish and want to take omega-3 pills instead, realize that they may not be beneficial, and remember to test for rancidity by breaking open a capsule from each bottle you purchase. If they smell fishy, throw the whole bottle out, since rancid fish oils increase risk for heart attacks and certain cancers.
• If you are a vegan who eats no seafood, be sure to eat a wide variety of plants and include lots of seeds (beans, nuts, whole grains, seed oils and so forth). Also take vitamin B12 pills to prevent nerve damage caused by lack of that vitamin.