Fish Oil and Heart Disease

by Glenn Gandelman, M.D., M.P.H. Health Professional

Fish oil contains Omega-3, a substance that has remarkable and beneficial effects on heart disease.

Omega-3 fatty acid is often misnamed an "alternative" or "natural" medication. Penicillin was, of course, derived from a living organism and was therefore "natural" in the same way that Omega-3s are natural. Currently, Omega-3 supplements are primarily derived from fish, and like penicillin, they have a therapeutic effect.

Omega-3 fatty acids are often referred to as "essential" fatty acids (EFAs) because they are needed for human health but are not sufficiently produced by the body.

The two major health promoting Omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are naturally found in certain cold-water fatty fish such as salmon, tuna, and mackerel. They can also be derived in the body from alpha-linolenic acid (ALA), which is an Omega-3 found in certain seeds and plant-based oils.

However, the body is very inefficient at converting ALA into EPA and DHA, which is why sufficient amounts of Omega-3s typically can not be obtained from plant-based sources alone.

Over the last century, the modern diet has become overloaded with unhealthy Omega-6 fatty acids (especially arachidonic acid) and largely depleted of the healthy Omega-3 essential fatty acids. The increased consumption of vegetable oils and shortenings, beef, and dairy is a major reason for this imbalance. The high amount of Omega-6 and low Omega-3 fatty acids in the Western diet are thought to contribute to an overall inflammatory state and possibly to cause heart disease. The North American population, in particular, has among the lowest dietary intake of Omega-3s found in the world and the highest amount of the harmful Omega-6s. .

Recent scientific developments have shown that the Omega-3s, in particular EPA and DHA, play a vital role in a healthy cardiovascular and central nervous systems, as well as, cognitive, joint, immune and metabolic function. EPA and DHA not only protect good overall physical and emotional health, but also can reduce the risk of heart disease and exert powerful anti-inflammatory effects that can help treat many diseases.

Cardiovascular benefits of Omega-3s include:

  • Reduction in death after a heart attack

  • Decrease in triglycerides and other bad cholesterol such as LDL

  • Increasing good cholesterol or HDL

  • Preventing abnormal heart rhythms

  • Preventing blockages of the heart's arteries.

Other diseases where Omega-3s may help include high blood pressure, arthritis, back pain, osteoporosis, psoriasis, lupus, Crohn's Disease, back pain, dry eyes, depression, bipolar disorder, ADHD, and stress-related disorders. Omega-3s are also important for pregnant women and infants, where their depletion may lead to visual or central nervous system problems in children.

Cardiovascular Benefits For several decades, it has been known that Greenland Eskimos, who eat fish as a large portion of their diet, experience lower rates of heart disease than other populations. Their diet, comprised of cold-water fish, seal, and whale, is high in Omega-3 content. Since the observation that populations high in fish consumption have lower rates of heart disease and other health problems, scientific evidence has shown that the Omega-3 essential fatty acids EPA and DHA help protect against cardiovascular disease.

The American Heart Association (AHA) now recommends the dietary intake of Omega-3s for both individuals with, and without, heart disease. The US Food and Drug Administration also claims that Omega-3s play a role in reducing coronary heart disease. Finally, the FDA has approved Omega-3 to treat high levels of triglycerides - a substance that can cause blockage of the hearts arteries and heart attacks.

Many clinical trials have shown that Omega-3 fatty acid supplements can reduce the risk of a number of different cardiovascular events, including sudden death, arrhythmias, heart attacks, and strokes. Studies of individuals who have survived a heart attack show that Omega-3s may decrease the risk of a second heart attack by nearly 30%, while individuals consuming even a moderate amount of Omega-3s may reduce their risk of a stroke by 50%. While it is not precisely known why Omega-3s confer such cardiovascular protective effects, it is likely that they work through several different mechanisms of action.

The Omega-3s EPA and DHA are believed to reduce blood clots inside arteries. These clots are caused by platelets sticking together and blocking blood flow to the heart and the brain among other organs. In addition to their effect on platelets, Omega-3s are seen to have anti-inflammatory effects. Inflammation may contribute to damage of blood vessels.

Numerous studies also confirm the important role that Omega-3s play in decreasing high triglycerides, a type of fat that can lead to arterial damage and now recognized as an independent risk factor for heart disease. The American Heart Association recommends that patients who need to lower their triglycerides should take 2-4 grams of EPA + DHA per day.

Other potential cardiovascular benefits of Omega-3s include lowering blood pressure and improving vascular tone. Studies of certain populations that consume more fish in their diets suggest that Omega-3s may also improve HDL, the body's "good cholesterol."

The American Heart Association now recommends the consumption of Omega-3 essential fatty acids for overall heart health, adding further that individuals with documented heart disease consume about 1 gram per day of EPA + DHA. Individuals with high triglycerides may benefit from higher doses of EPA and DHA. Supplementing one's diet with an adequate amount of Omega-3s to promote cardiac health can be safely done with high-purity supplements free of environmental contaminants.

Dietary Supplementation with Omega-3 Products Although the beneficial effects of Omega-3s are clear, there are several factors to consider in selecting a specific brand: fish contain heavy metals such as mercury and other toxins that should be avoided; some forms of omega-3 fatty acids are less purified and contain harmful saturated fats; there is a dramatic difference in the cost of omega-3s; there should be an optimal balance of both DHA and EPA.

Since some larger fish species may contain high levels of mercury, polychlorinated biphenyls (PCBs), dioxins or other contaminants, achieving an optimal amount of Omega-3s through the intake of fish alone raises a number of safety concerns. Omega-3 supplements that are certified free of environmental contaminants offer a safe way to obtain health-promoting benefits.

Most brands of Omega-3 products successfully remove contaminants from fish. In fact, the highly purified Omega-3 supplements that are now available on the market provide extremely safe and efficient EPA and DHA.

The majority of omega-3 products contain unhealthy saturated fats. In fact, there were no products at my local pharmacy that didn't contain 30-50% saturated fats. The same was true at my local nutritional store.

The only two products that are overwhelmingly Omega-3 essential fatty acids are the prescription omega-3 Omacor ( and the over-the-counter Omax3 ( These supplements are very similar (both provide >/= 90% pure omega-3s per serving). Table 1 compares many Omega-3s currently available.

The table below lists many of the available Omega-3 products on the market.



Concentration of Total Omega-3s

Concentration of EPA + DHA

Cost for 1g of Omega-3s *


Internet/some stores



$0.78 1


By Prescription



$1.66 2

IcelandHealth Maximum Strength Omega-3

Internet/some stores



$1.67 3

Purity Products Omega-3




$0.93 4

N.V. Perricone MD Omega-3




$1.80 5

Nature's Bounty Omega-3

Retail Stores



$0.35 6

Nordic Naturals EPA Extra

Internet/some stores



$0.87 7

Nordic Naturals Omega-3

Internet/some stores



$0.83 8

Nature's Way Fisol Fish Oil

Internet/some stores



$0.76 9

Life Fitness Omega-3

Retail Stores



$0.39 10

For internet purchases, does not include shipping/handling costs; for retail store purchase, does not include sales tax

  1. Price based on purchase of 1 box at ($34.95 per box; 60 825 mg capsules)

  2. Price based on pharmacy retail, at $44.69 for 30 one gram capsules

  3. Price based on purchase of 1 box at ($49.95 per box; 30 one gram capsules)

  4. Price based on purchase of 1 box at ($34.95 per box; 60 one gram capsules)

  5. Price based on purchase of 1 box at ($97 per bottle; 270 one gram capsules)

  6. Price based on purchase of 1 bottle at retail outlet ($5.99 per bottle; 50 one gram capsules)

  7. Price based on purchase of 1 bottle at ($39.95 per bottle; 60 one gram capsules)

  8. Price based on purchase of 1 bottle at ($14.95 per bottle; 60 one gram capsules)

  9. Price based on purchase of 1 bottle at retail outlet ($16.99 per bottle; 90 500 mg capsules)

  10. Price based on purchase of 1 bottle at retail outlet ($7.99 per bottle; 60 one gram capsules)**


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Glenn Gandelman, M.D., M.P.H.
Meet Our Writer
Glenn Gandelman, M.D., M.P.H.

Dr. Glenn Gandelman is board certified in internal medicine, cardiology, echocardiography, and nuclear medicine. He specializes in prevention, diagnosis and treatment of cardiovascular disease. He wrote for HealthCentral as a health professional for Heart Disease and High Blood Pressure.