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Fish Oil Supplements & Your Heart

Fish oil. It is one of the most commonly used supplements these days, estimated to be taken by 19 million adults in the U.S. alone. In the media, claims of its health benefits are broad and ubiquitous, ranging from heart disease and cancer prevention to treatment of ADHD. However, while there is little doubt that a diet rich in omega-3 foods is beneficial, do fish oil supplements—which also provide omega-3 fats—confer the same benefits for your health? And what if you are currently on one or thinking about starting—what are the ‘right’ reasons for doing so and the potential risks to consider? And finally, what should you look for in a product?

In answering these questions today, I hope to equip you with the confidence to make the best decisions in regards to your health.

Fish Oil at a Glance – Key Points

  • Omega-3 fatty acids are important for the maintenance of health.

  • Fatty fish is the best way of obtaining crucial EPA and DHA, but a fish oil supplement may help if one is having trouble getting enough through food.

  • Past and ongoing research demonstrate that diets rich in omega-3 fats confer numerous health benefits, but whether the same degree of benefit can be derived from fish oil supplements is still unclear in some areas.

  • While omega-3 fats from food have been shown to protect against heart attacks and strokes, fish oil supplements have not been proven to confer the same benefit.

  • Studies on fish oil supplements suggest that they can be beneficial to those with high triglycerides, high blood pressure, rheumatoid arthritis, mild cognitive impairment, and women who are pregnant or breastfeeding.

  • For those already on blood-thinning medications, taking fish oil in combination may potentially increase the risk of bleeding.

  • Ultimately, whether you should take a daily fish oil supplement should be a decision made in conjunction with your physician, as he or she can help you weigh the potential benefits and risks given your personal health status.

• • •

Heart Health Benefits

The Current Evidence

Heart Attacks and Strokes

The bottom line: This is where some of the confusion lies, but as of now, there is no clear evidence that fish oil supplements help prevent heart attacks or strokes. Diets rich in omega-3 fats do confer this benefit, however.

A closer look:

  • From the 1960’s to 2005, many studies had been conducted to evaluate the effects of omega-3 supplements (ie. fish oil), on heart disease risk. In these studies, researchers compared the number of heart attacks and strokes in people who took omega-3 supplements with those who didn’t. The conclusions of these studies were inconsistent with each other, with some indicating that the supplements were protective in that they lowered the risk of heart attacks and strokes, while others showed no benefit at all.

  • At the same time, studies looking at people who consumed foods rich in omega-3 fats found that they consistently had lower rates of heart attacks and strokes (both in healthy people and those who already had heart disease).

  • In 2012, in order to take a closer look, two groups of scientists went back and gathered these previous studies and cross-analyzed the data (in what is called a meta-analysis). Neither group found convincing evidence of a protective effect of fish oil supplements.

  • In 2014, researchers re-examined the results of the newest high-quality studies, all of which were completed in 2005 or later. Of the nine studies evaluated, only one showed clear evidence of a beneficial effect.


Studies have shown that high doses of fish oil supplements (up to 4 grams/day) can significantly reduce triglyceride levels (high levels of which can lead to pancreatitis and heart disease) and is currently used as a prescribed treatment for this purpose. (Note: Such doses of fish oil should never be taken without the supervision of a physician.)


Both omega-3’s from food and fish oil supplementation can improve good HDL cholesterol. However, it has little effect on bad LDL cholesterol (and high supplement doses may actually increase LDL). Therefore, given its ‘neutral’ effect on cholesterol, fish oil supplements should not be taken solely for this purpose. If you are looking to naturally lower your cholesterol, this article will help.

Blood Pressure

Both dietary omega-3’s and fish oil supplementation have been shown to slightly improve blood pressure in people with high blood pressure.

Cardiac Arrhythmias

A few studies suggest that in people who are at risk of having abnormal heart rhythms, both omega-3 from food and fish oil supplementation may reduce the risk of an fatal event.

Fish Oil Safety

Bleeding risk:

Fish oil (as well as fatty fish in extremely large amounts) can have an antiplatelet effect (like aspirin), prolonging the time it takes for your blood to clot. Therefore, if you are already taking aspirin, warfarin (Coumadin), clopidogrel (Plavix), or nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen or naproxen on a regular basis, taking fish oil supplements in combination technically may increase your risk of bleeding. The same goes for herbal supplements—some that are known to have ‘blood-thinning’ properties are ginkgo biloba, garlic, and saw palmetto.

With that said, the actual risk of a bleeding event depends largely on the dose of medications/supplements and fish oil you take. Although most research suggest that fairly large doses of fish oil (2-3 grams or more daily) are required before this effect becomes significant, if you take any of these medications or supplements, it is crucial that you let your doctor know, as he or she can help you weigh the potential health risks and benefits to decide what you should take and to adjust the dosages if necessary.

Other issues to consider:

  • Side effects: Side effects of fish oil are uncommon and typically consist of minor gastrointestinal symptoms, such as belching, indigestion, or diarrhea.

  • Fish allergy: It is still uncertain whether people with fish or shellfish allergies can safely consume fish oil supplements.

  • Prostate cancer risk: As noted above, there is widely conflicting evidence about whether omega-3 fatty acids found in fish and fish oil affect the risk of prostate cancer, and more data is needed before this can be considered conclusive.

Selecting a Supplement

If you find that you cannot incorporate enough fish into your diet to meet the daily goal (500 mg/day for adults), a fish oil supplement may be helpful. Things to consider when shopping for one:

  • Concentration/serving size: Many supplements contain up to 1,000 mg of fish oil per serving but only 300 mg of EPA/DHA. Choose a supplement that contains at least 500 mg of combined EPA/DHA per 1,000 mg of fish oil.

  • Purity & authenticity: Not all fish oil supplements contain what they say they do. To ensure a quality product, choose a supplement that is “third-party tested” or has the GOED standard of purity.

  • Sustainability: Try to buy fish oil that is certified by the MSC, the Environmental Defense Fund, or a similar organization. Small fish with short lifespans tend to be more sustainable.

Other types of omega-3 supplements:

  • Algal oils: The oil from algae is a rich source of EPA/DHA and is a good option for vegetarians and vegans.

  • ALA supplements: These are made from plant sources (eg. flaxseed, chia, and hemp seeds) and contain omega-3’s in the form of ALA but contain no EPA/DHA. However, as about 10% of ALA will get converted by your body into EPA/DHA, a tablespoon of flaxseed oil that provides 7 grams of ALA will yield approximately 0.7 grams of EPA/DHA.

  • Fish liver oils: Fish liver oils such as cod liver oil, are not the same as fish oil. Fish liver oils contain vitamins A and D as well as omega-3 fatty acids. Avoid getting these as both of these vitamins can accumulate to toxic doses in your body if taken in abundance.

Once purchased, store your supplements away from light, in a cool, dry place or a refrigerator. To ensure best absorption, take the supplement with your largest meal.As fish oil will eventually oxidize and go rancid, open a capsule once in a while to check the odor.

If you take several different daily supplements, the chart below can help you plan your regimen:

The Bottom Line

There is no question that a balanced diet consisting of seafood rich in omega-3 fats is beneficial. The question remains, though, whether omega-3 supplements are beneficial to the same degree. Therefore, the decision to use fish oil should always be made with your physician who can take into account your overall health, medical conditions, current medications, and potential risks. This is especially important if you are someone who is pregnant or breastfeeding, are on blood-thinning medications, or are allergic to seafood.

With that said, here’s to better health for better days!

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